diff options
| author | Linus Torvalds | 2011-03-15 15:48:13 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2011-03-15 15:48:13 -0700 |
| commit | 422e6c4bc4b48c15b3cb57a1ca71431abfc57e54 (patch) | |
| tree | 81ceb21f84a79e796ee33b5d17e17406f096abcb | |
| parent | c83ce989cb5ff86575821992ea82c4df5c388ebc (diff) | |
| parent | 574197e0de46a8a4db5c54ef7b65e43ffa8873a7 (diff) | |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (57 commits)
tidy the trailing symlinks traversal up
Turn resolution of trailing symlinks iterative everywhere
simplify link_path_walk() tail
Make trailing symlink resolution in path_lookupat() iterative
update nd->inode in __do_follow_link() instead of after do_follow_link()
pull handling of one pathname component into a helper
fs: allow AT_EMPTY_PATH in linkat(), limit that to CAP_DAC_READ_SEARCH
Allow passing O_PATH descriptors via SCM_RIGHTS datagrams
readlinkat(), fchownat() and fstatat() with empty relative pathnames
Allow O_PATH for symlinks
New kind of open files - "location only".
ext4: Copy fs UUID to superblock
ext3: Copy fs UUID to superblock.
vfs: Export file system uuid via /proc/<pid>/mountinfo
unistd.h: Add new syscalls numbers to asm-generic
x86: Add new syscalls for x86_64
x86: Add new syscalls for x86_32
fs: Remove i_nlink check from file system link callback
fs: Don't allow to create hardlink for deleted file
vfs: Add open by file handle support
...
57 files changed, 1483 insertions, 1253 deletions
diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c index fe698b5045e9..376f22130791 100644 --- a/arch/alpha/kernel/osf_sys.c +++ b/arch/alpha/kernel/osf_sys.c @@ -230,44 +230,24 @@ linux_to_osf_statfs(struct kstatfs *linux_stat, struct osf_statfs __user *osf_st return copy_to_user(osf_stat, &tmp_stat, bufsiz) ? -EFAULT : 0; } -static int -do_osf_statfs(struct path *path, struct osf_statfs __user *buffer, - unsigned long bufsiz) +SYSCALL_DEFINE3(osf_statfs, const char __user *, pathname, + struct osf_statfs __user *, buffer, unsigned long, bufsiz) { struct kstatfs linux_stat; - int error = vfs_statfs(path, &linux_stat); + int error = user_statfs(pathname, &linux_stat); if (!error) error = linux_to_osf_statfs(&linux_stat, buffer, bufsiz); return error; } -SYSCALL_DEFINE3(osf_statfs, const char __user *, pathname, - struct osf_statfs __user *, buffer, unsigned long, bufsiz) -{ - struct path path; - int retval; - - retval = user_path(pathname, &path); - if (!retval) { - retval = do_osf_statfs(&path, buffer, bufsiz); - path_put(&path); - } - return retval; -} - SYSCALL_DEFINE3(osf_fstatfs, unsigned long, fd, struct osf_statfs __user *, buffer, unsigned long, bufsiz) { - struct file *file; - int retval; - - retval = -EBADF; - file = fget(fd); - if (file) { - retval = do_osf_statfs(&file->f_path, buffer, bufsiz); - fput(file); - } - return retval; + struct kstatfs linux_stat; + int error = fd_statfs(fd, &linux_stat); + if (!error) + error = linux_to_osf_statfs(&linux_stat, buffer, bufsiz); + return error; } /* diff --git a/arch/parisc/hpux/sys_hpux.c b/arch/parisc/hpux/sys_hpux.c index 30394081d9b6..6ab9580b0b00 100644 --- a/arch/parisc/hpux/sys_hpux.c +++ b/arch/parisc/hpux/sys_hpux.c @@ -185,26 +185,21 @@ struct hpux_statfs { int16_t f_pad; }; -static int do_statfs_hpux(struct path *path, struct hpux_statfs *buf) +static int do_statfs_hpux(struct kstatfs *st, struct hpux_statfs __user *p) { - struct kstatfs st; - int retval; - - retval = vfs_statfs(path, &st); - if (retval) - return retval; - - memset(buf, 0, sizeof(*buf)); - buf->f_type = st.f_type; - buf->f_bsize = st.f_bsize; - buf->f_blocks = st.f_blocks; - buf->f_bfree = st.f_bfree; - buf->f_bavail = st.f_bavail; - buf->f_files = st.f_files; - buf->f_ffree = st.f_ffree; - buf->f_fsid[0] = st.f_fsid.val[0]; - buf->f_fsid[1] = st.f_fsid.val[1]; - + struct hpux_statfs buf; + memset(&buf, 0, sizeof(buf)); + buf.f_type = st->f_type; + buf.f_bsize = st->f_bsize; + buf.f_blocks = st->f_blocks; + buf.f_bfree = st->f_bfree; + buf.f_bavail = st->f_bavail; + buf.f_files = st->f_files; + buf.f_ffree = st->f_ffree; + buf.f_fsid[0] = st->f_fsid.val[0]; + buf.f_fsid[1] = st->f_fsid.val[1]; + if (copy_to_user(p, &buf, sizeof(buf))) + return -EFAULT; return 0; } @@ -212,35 +207,19 @@ static int do_statfs_hpux(struct path *path, struct hpux_statfs *buf) asmlinkage long hpux_statfs(const char __user *pathname, struct hpux_statfs __user *buf) { - struct path path; - int error; - - error = user_path(pathname, &path); - if (!error) { - struct hpux_statfs tmp; - error = do_statfs_hpux(&path, &tmp); - if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) - error = -EFAULT; - path_put(&path); - } + struct kstatfs st; + int error = user_statfs(pathname, &st); + if (!error) + error = do_statfs_hpux(&st, buf); return error; } asmlinkage long hpux_fstatfs(unsigned int fd, struct hpux_statfs __user * buf) { - struct file *file; - struct hpux_statfs tmp; - int error; - - error = -EBADF; - file = fget(fd); - if (!file) - goto out; - error = do_statfs_hpux(&file->f_path, &tmp); - if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) - error = -EFAULT; - fput(file); - out: + struct kstatfs st; + int error = fd_statfs(fd, &st); + if (!error) + error = do_statfs_hpux(&st, buf); return error; } diff --git a/arch/powerpc/platforms/cell/spufs/syscalls.c b/arch/powerpc/platforms/cell/spufs/syscalls.c index 187a7d32f86a..a3d2ce54ea2e 100644 --- a/arch/powerpc/platforms/cell/spufs/syscalls.c +++ b/arch/powerpc/platforms/cell/spufs/syscalls.c @@ -70,7 +70,7 @@ static long do_spu_create(const char __user *pathname, unsigned int flags, if (!IS_ERR(tmp)) { struct nameidata nd; - ret = path_lookup(tmp, LOOKUP_PARENT, &nd); + ret = kern_path_parent(tmp, &nd); if (!ret) { nd.flags |= LOOKUP_OPEN | LOOKUP_CREATE; ret = spufs_create(&nd, flags, mode, neighbor); diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c index 975613b23dcf..c70e047eed72 100644 --- a/arch/um/drivers/mconsole_kern.c +++ b/arch/um/drivers/mconsole_kern.c @@ -124,35 +124,18 @@ void mconsole_log(struct mc_request *req) #if 0 void mconsole_proc(struct mc_request *req) { - struct nameidata nd; struct vfsmount *mnt = current->nsproxy->pid_ns->proc_mnt; struct file *file; - int n, err; + int n; char *ptr = req->request.data, *buf; mm_segment_t old_fs = get_fs(); ptr += strlen("proc"); ptr = skip_spaces(ptr); - err = vfs_path_lookup(mnt->mnt_root, mnt, ptr, LOOKUP_FOLLOW, &nd); - if (err) { - mconsole_reply(req, "Failed to look up file", 1, 0); - goto out; - } - - err = may_open(&nd.path, MAY_READ, O_RDONLY); - if (result) { - mconsole_reply(req, "Failed to open file", 1, 0); - path_put(&nd.path); - goto out; - } - - file = dentry_open(nd.path.dentry, nd.path.mnt, O_RDONLY, - current_cred()); - err = PTR_ERR(file); + file = file_open_root(mnt->mnt_root, mnt, ptr, O_RDONLY); if (IS_ERR(file)) { mconsole_reply(req, "Failed to open file", 1, 0); - path_put(&nd.path); goto out; } diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index 518bb99c3394..98d353edfff3 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -851,4 +851,6 @@ ia32_sys_call_table: .quad sys_fanotify_init .quad sys32_fanotify_mark .quad sys_prlimit64 /* 340 */ + .quad sys_name_to_handle_at + .quad compat_sys_open_by_handle_at ia32_syscall_end: diff --git a/arch/x86/include/asm/unistd_32.h b/arch/x86/include/asm/unistd_32.h index b766a5e8ba0e..f4c4973fc2ac 100644 --- a/arch/x86/include/asm/unistd_32.h +++ b/arch/x86/include/asm/unistd_32.h @@ -346,10 +346,12 @@ #define __NR_fanotify_init 338 #define __NR_fanotify_mark 339 #define __NR_prlimit64 340 +#define __NR_name_to_handle_at 341 +#define __NR_open_by_handle_at 342 #ifdef __KERNEL__ -#define NR_syscalls 341 +#define NR_syscalls 343 #define __ARCH_WANT_IPC_PARSE_VERSION #define __ARCH_WANT_OLD_READDIR diff --git a/arch/x86/include/asm/unistd_64.h b/arch/x86/include/asm/unistd_64.h index 363e9b8a715b..81a3d5b70235 100644 --- a/arch/x86/include/asm/unistd_64.h +++ b/arch/x86/include/asm/unistd_64.h @@ -669,6 +669,10 @@ __SYSCALL(__NR_fanotify_init, sys_fanotify_init) __SYSCALL(__NR_fanotify_mark, sys_fanotify_mark) #define __NR_prlimit64 302 __SYSCALL(__NR_prlimit64, sys_prlimit64) +#define __NR_name_to_handle_at 303 +__SYSCALL(__NR_name_to_handle_at, sys_name_to_handle_at) +#define __NR_open_by_handle_at 304 +__SYSCALL(__NR_open_by_handle_at, sys_open_by_handle_at) #ifndef __NO_STUBS #define __ARCH_WANT_OLD_READDIR diff --git a/arch/x86/kernel/syscall_table_32.S b/arch/x86/kernel/syscall_table_32.S index b35786dc9b8f..c314b2199efd 100644 --- a/arch/x86/kernel/syscall_table_32.S +++ b/arch/x86/kernel/syscall_table_32.S @@ -340,3 +340,5 @@ ENTRY(sys_call_table) .long sys_fanotify_init .long sys_fanotify_mark .long sys_prlimit64 /* 340 */ + .long sys_name_to_handle_at + .long sys_open_by_handle_at diff --git a/fs/Kconfig b/fs/Kconfig index 3db9caa57edc..7cb53aafac1e 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -47,7 +47,7 @@ config FS_POSIX_ACL def_bool n config EXPORTFS - tristate + bool config FILE_LOCKING bool "Enable POSIX file locking API" if EXPERT diff --git a/fs/Makefile b/fs/Makefile index a7f7cef0c0c8..ba01202844c5 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -48,6 +48,8 @@ obj-$(CONFIG_FS_POSIX_ACL) += posix_acl.o xattr_acl.o obj-$(CONFIG_NFS_COMMON) += nfs_common/ obj-$(CONFIG_GENERIC_ACL) += generic_acl.o +obj-$(CONFIG_FHANDLE) += fhandle.o + obj-y += quota/ obj-$(CONFIG_PROC_FS) += proc/ diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c index ff27d7a477b2..b4ffad859adb 100644 --- a/fs/btrfs/export.c +++ b/fs/btrfs/export.c @@ -21,9 +21,13 @@ static int btrfs_encode_fh(struct dentry *dentry, u32 *fh, int *max_len, int len = *max_len; int type; - if ((len < BTRFS_FID_SIZE_NON_CONNECTABLE) || - (connectable && len < BTRFS_FID_SIZE_CONNECTABLE)) + if (connectable && (len < BTRFS_FID_SIZE_CONNECTABLE)) { + *max_len = BTRFS_FID_SIZE_CONNECTABLE; return 255; + } else if (len < BTRFS_FID_SIZE_NON_CONNECTABLE) { + *max_len = BTRFS_FID_SIZE_NON_CONNECTABLE; + return 255; + } len = BTRFS_FID_SIZE_NON_CONNECTABLE; type = FILEID_BTRFS_WITHOUT_PARENT; diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 9007bbd01dbf..4a0107e18747 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4806,9 +4806,6 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir, int err; int drop_inode = 0; - if (inode->i_nlink == 0) - return -ENOENT; - /* do not allow sys_link's with other subvols of the same device */ if (root->objectid != BTRFS_I(inode)->root->objectid) return -EPERM; diff --git a/fs/compat.c b/fs/compat.c index 691c3fd8ce1d..c6d31a3bab88 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -262,35 +262,19 @@ static int put_compat_statfs(struct compat_statfs __user *ubuf, struct kstatfs * */ asmlinkage long compat_sys_statfs(const char __user *pathname, struct compat_statfs __user *buf) { - struct path path; - int error; - - error = user_path(pathname, &path); - if (!error) { - struct kstatfs tmp; - error = vfs_statfs(&path, &tmp); - if (!error) - error = put_compat_statfs(buf, &tmp); - path_put(&path); - } + struct kstatfs tmp; + int error = user_statfs(pathname, &tmp); + if (!error) + error = put_compat_statfs(buf, &tmp); return error; } asmlinkage long compat_sys_fstatfs(unsigned int fd, struct compat_statfs __user *buf) { - struct file * file; struct kstatfs tmp; - int error; - - error = -EBADF; - file = fget(fd); - if (!file) - goto out; - error = vfs_statfs(&file->f_path, &tmp); + int error = fd_statfs(fd, &tmp); if (!error) error = put_compat_statfs(buf, &tmp); - fput(file); -out: return error; } @@ -329,41 +313,29 @@ static int put_compat_statfs64(struct compat_statfs64 __user *ubuf, struct kstat asmlinkage long compat_sys_statfs64(const char __user *pathname, compat_size_t sz, struct compat_statfs64 __user *buf) { - struct path path; + struct kstatfs tmp; int error; if (sz != sizeof(*buf)) return -EINVAL; - error = user_path(pathname, &path); - if (!error) { - struct kstatfs tmp; - error = vfs_statfs(&path, &tmp); - if (!error) - error = put_compat_statfs64(buf, &tmp); - path_put(&path); - } + error = user_statfs(pathname, &tmp); + if (!error) + error = put_compat_statfs64(buf, &tmp); return error; } asmlinkage long compat_sys_fstatfs64(unsigned int fd, compat_size_t sz, struct compat_statfs64 __user *buf) { - struct file * file; struct kstatfs tmp; int error; if (sz != sizeof(*buf)) return -EINVAL; - error = -EBADF; - file = fget(fd); - if (!file) - goto out; - error = vfs_statfs(&file->f_path, &tmp); + error = fd_statfs(fd, &tmp); if (!error) error = put_compat_statfs64(buf, &tmp); - fput(file); -out: return error; } @@ -2312,3 +2284,16 @@ asmlinkage long compat_sys_timerfd_gettime(int ufd, } #endif /* CONFIG_TIMERFD */ + +#ifdef CONFIG_FHANDLE +/* + * Exactly like fs/open.c:sys_open_by_handle_at(), except that it + * doesn't set the O_LARGEFILE flag. + */ +asmlinkage long +compat_sys_open_by_handle_at(int mountdirfd, + struct file_handle __user *handle, int flags) +{ + return do_handle_open(mountdirfd, handle, flags); +} +#endif diff --git a/fs/exec.c b/fs/exec.c index 52a447d9b6ab..ba99e1abb1aa 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -115,13 +115,16 @@ SYSCALL_DEFINE1(uselib, const char __user *, library) struct file *file; char *tmp = getname(library); int error = PTR_ERR(tmp); + static const struct open_flags uselib_flags = { + .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, + .acc_mode = MAY_READ | MAY_EXEC | MAY_OPEN, + .intent = LOOKUP_OPEN + }; if (IS_ERR(tmp)) goto out; - file = do_filp_open(AT_FDCWD, tmp, - O_LARGEFILE | O_RDONLY | __FMODE_EXEC, 0, - MAY_READ | MAY_EXEC | MAY_OPEN); + file = do_filp_open(AT_FDCWD, tmp, &uselib_flags, LOOKUP_FOLLOW); putname(tmp); error = PTR_ERR(file); if (IS_ERR(file)) @@ -721,10 +724,13 @@ struct file *open_exec(const char *name) { struct file *file; int err; + static const struct open_flags open_exec_flags = { + .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, + .acc_mode = MAY_EXEC | MAY_OPEN, + .intent = LOOKUP_OPEN + }; - file = do_filp_open(AT_FDCWD, name, - O_LARGEFILE | O_RDONLY | __FMODE_EXEC, 0, - MAY_EXEC | MAY_OPEN); + file = do_filp_open(AT_FDCWD, name, &open_exec_flags, LOOKUP_FOLLOW); if (IS_ERR(file)) goto out; diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c index 4b6825740dd5..b05acb796135 100644 --- a/fs/exportfs/expfs.c +++ b/fs/exportfs/expfs.c @@ -320,9 +320,14 @@ static int export_encode_fh(struct dentry *dentry, struct fid *fid, struct inode * inode = dentry->d_inode; int len = *max_len; int type = FILEID_INO32_GEN; - - if (len < 2 || (connectable && len < 4)) + + if (connectable && (len < 4)) { + *max_len = 4; + return 255; + } else if (len < 2) { + *max_len = 2; return 255; + } len = 2; fid->i32.ino = inode->i_ino; @@ -369,6 +374,8 @@ struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid, /* * Try to get any dentry for the given file handle from the filesystem. */ + if (!nop || !nop->fh_to_dentry) + return ERR_PTR(-ESTALE); result = nop->fh_to_dentry(mnt->mnt_sb, fid, fh_len, fileid_type); if (!result) result = ERR_PTR(-ESTALE); diff --git a/fs/ext3/namei.c b/fs/ext3/namei.c index b27ba71810ec..561f69256266 100644 --- a/fs/ext3/namei.c +++ b/fs/ext3/namei.c @@ -2253,13 +2253,6 @@ static int ext3_link (struct dentry * old_dentry, dquot_initialize(dir); - /* - * Return -ENOENT if we've raced with unlink and i_nlink is 0. Doing - * otherwise has the potential to corrupt the orphan inode list. - */ - if (inode->i_nlink == 0) - return -ENOENT; - retry: handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS(dir->i_sb) + EXT3_INDEX_EXTRA_TRANS_BLOCKS); diff --git a/fs/ext3/super.c b/fs/ext3/super.c index 85c8cc8f2473..9cc19a1dea8e 100644 --- a/fs/ext3/super.c +++ b/fs/ext3/super.c @@ -1936,6 +1936,7 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent) sb->s_qcop = &ext3_qctl_operations; sb->dq_op = &ext3_quota_operations; #endif + memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid)); INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */ mutex_init(&sbi->s_orphan_lock); mutex_init(&sbi->s_resize_lock); diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 5485390d32c5..e781b7ea5630 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2304,13 +2304,6 @@ static int ext4_link(struct dentry *old_dentry, dquot_initialize(dir); - /* - * Return -ENOENT if we've raced with unlink and i_nlink is 0. Doing - * otherwise has the potential to corrupt the orphan inode list. - */ - if (inode->i_nlink == 0) - return -ENOENT; - retry: handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + EXT4_INDEX_EXTRA_TRANS_BLOCKS); diff --git a/fs/ext4/super.c b/fs/ext4/super.c index f6a318f836b2..5977b356a435 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3415,6 +3415,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) sb->s_qcop = &ext4_qctl_operations; sb->dq_op = &ext4_quota_operations; #endif + memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid)); + INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */ mutex_init(&sbi->s_orphan_lock); mutex_init(&sbi->s_resize_lock); diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 86753fe10bd1..0e277ec4b612 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -757,8 +757,10 @@ fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable) struct inode *inode = de->d_inode; u32 ipos_h, ipos_m, ipos_l; - if (len < 5) + if (len < 5) { + *lenp = 5; return 255; /* no room */ + } ipos_h = MSDOS_I(inode)->i_pos >> 8; ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24; diff --git a/fs/fcntl.c b/fs/fcntl.c index cb1026181bdc..6c82e5bac039 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -131,7 +131,7 @@ SYSCALL_DEFINE2(dup2, unsigned int, oldfd, unsigned int, newfd) SYSCALL_DEFINE1(dup, unsigned int, fildes) { int ret = -EBADF; - struct file *file = fget(fildes); + struct file *file = fget_raw(fildes); if (file) { ret = get_unused_fd(); @@ -426,15 +426,35 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, return err; } +static int check_fcntl_cmd(unsigned cmd) +{ + switch (cmd) { + case F_DUPFD: + case F_DUPFD_CLOEXEC: + case F_GETFD: + case F_SETFD: + case F_GETFL: + return 1; + } + return 0; +} + SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg) { struct file *filp; long err = -EBADF; - filp = fget(fd); + filp = fget_raw(fd); if (!filp) goto out; + if (unlikely(filp->f_mode & FMODE_PATH)) { + if (!check_fcntl_cmd(cmd)) { + fput(filp); + goto out; + } + } + err = security_file_fcntl(filp, cmd, arg); if (err) { fput(filp); @@ -456,10 +476,17 @@ SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, long err; err = -EBADF; - filp = fget(fd); + filp = fget_raw(fd); if (!filp) goto out; + if (unlikely(filp->f_mode & FMODE_PATH)) { + if (!check_fcntl_cmd(cmd)) { + fput(filp); + goto out; + } + } + err = security_file_fcntl(filp, cmd, arg); if (err) { fput(filp); @@ -808,14 +835,14 @@ static int __init fcntl_init(void) * Exceptions: O_NONBLOCK is a two bit define on parisc; O_NDELAY * is defined as O_NONBLOCK on some platforms and not on others. */ - BUILD_BUG_ON(18 - 1 /* for O_RDONLY being 0 */ != HWEIGHT32( + BUILD_BUG_ON(19 - 1 /* for O_RDONLY being 0 */ != HWEIGHT32( O_RDONLY | O_WRONLY | O_RDWR | O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC | O_APPEND | /* O_NONBLOCK | */ __O_SYNC | O_DSYNC | FASYNC | O_DIRECT | O_LARGEFILE | O_DIRECTORY | O_NOFOLLOW | O_NOATIME | O_CLOEXEC | - __FMODE_EXEC + __FMODE_EXEC | O_PATH )); fasync_cache = kmem_cache_create("fasync_cache", diff --git a/fs/fhandle.c b/fs/fhandle.c new file mode 100644 index 000000000000..bf93ad2bee07 --- /dev/null +++ b/fs/fhandle.c @@ -0,0 +1,265 @@ +#include <linux/syscalls.h> +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/mount.h> +#include <linux/namei.h> +#include <linux/exportfs.h> +#include <linux/fs_struct.h> +#include <linux/fsnotify.h> +#include <asm/uaccess.h> +#include "internal.h" + +static long do_sys_name_to_handle(struct path *path, + struct file_handle __user *ufh, + int __user *mnt_id) +{ + long retval; + struct file_handle f_handle; + int handle_dwords, handle_bytes; + struct file_handle *handle = NULL; + + /* + * We need t make sure wether the file system + * support decoding of the file handle + */ + if (!path->mnt->mnt_sb->s_export_op || + !path->mnt->mnt_sb->s_export_op->fh_to_dentry) + return -EOPNOTSUPP; + + if (copy_from_user(&f_handle, ufh, sizeof(struct file_handle))) + return -EFAULT; + + if (f_handle.handle_bytes > MAX_HANDLE_SZ) + return -EINVAL; + + handle = kmalloc(sizeof(struct file_handle) + f_handle.handle_bytes, + GFP_KERNEL); + if (!handle) + return -ENOMEM; + + /* convert handle size to multiple of sizeof(u32) */ + handle_dwords = f_handle.handle_bytes >> 2; + + /* we ask for a non connected handle */ + retval = exportfs_encode_fh(path->dentry, + (struct fid *)handle->f_handle, + &handle_dwords, 0); + handle->handle_type = retval; + /* convert handle size to bytes */ + handle_bytes = handle_dwords * sizeof(u32); + handle->handle_bytes = handle_bytes; + if ((handle->handle_bytes > f_handle.handle_bytes) || + (retval == 255) || (retval == -ENOSPC)) { + /* As per old exportfs_encode_fh documentation + * we could return ENOSPC to indicate overflow + * But file system returned 255 always. So handle + * both the values + */ + /* + * set the handle size to zero so we copy only + * non variable part of the file_handle + */ + handle_bytes = 0; + retval = -EOVERFLOW; + } else + retval = 0; + /* copy the mount id */ + if (copy_to_user(mnt_id, &path->mnt->mnt_id, sizeof(*mnt_id)) || + copy_to_user(ufh, handle, + sizeof(struct file_handle) + handle_bytes)) + retval = -EFAULT; + kfree(handle); + return retval; +} + +/** + * sys_name_to_handle_at: convert name to handle + * @dfd: directory relative to which name is interpreted if not absolute + * @name: name that should be converted to handle. + * @handle: resulting file handle + * @mnt_id: mount id of the file system containing the file + * @flag: flag value to indicate whether to follow symlink or not + * + * @handle->handle_size indicate the space available to store the + * variable part of the file handle in bytes. If there is not + * enough space, the field is updated to return the minimum + * value required. + */ +SYSCALL_DEFINE5(name_to_handle_at, int, dfd, const char __user *, name, + struct file_handle __user *, handle, int __user *, mnt_id, + int, flag) +{ + struct path path; + int lookup_flags; + int err; + + if ((flag & ~(AT_SYMLINK_FOLLOW | AT_EMPTY_PATH)) != 0) + return -EINVAL; + + lookup_flags = (flag & AT_SYMLINK_FOLLOW) ? LOOKUP_FOLLOW : 0; + if (flag & AT_EMPTY_PATH) + lookup_flags |= LOOKUP_EMPTY; + err = user_path_at(dfd, name, lookup_flags, &path); + if (!err) { + err = do_sys_name_to_handle(&path, handle, mnt_id); + path_put(&path); + } + return err; +} + +static struct vfsmount *get_vfsmount_from_fd(int fd) +{ + struct path path; + + if (fd == AT_FDCWD) { + struct fs_struct *fs = current->fs; + spin_lock(&fs->lock); + path = fs->pwd; + mntget(path.mnt); + spin_unlock(&fs->lock); + } else { + int fput_needed; + struct file *file = fget_light(fd, &fput_needed); + if (!file) + return ERR_PTR(-EBADF); + path = file->f_path; + mntget(path.mnt); + fput_light(file, fput_needed); + } + return path.mnt; +} + +static int vfs_dentry_acceptable(void *context, struct dentry *dentry) +{ + return 1; +} + +static int do_handle_to_path(int mountdirfd, struct file_handle *handle, + struct path *path) +{ + int retval = 0; + int handle_dwords; + + path->mnt = get_vfsmount_from_fd(mountdirfd); + if (IS_ERR(path->mnt)) { + retval = PTR_ERR(path->mnt); + goto out_err; + } + /* change the handle size to multiple of sizeof(u32) */ + handle_dwords = handle->handle_bytes >> 2; + path->dentry = exportfs_decode_fh(path->mnt, + (struct fid *)handle->f_handle, + handle_dwords, handle->handle_type, + vfs_dentry_acceptable, NULL); + if (IS_ERR(path->dentry)) { + retval = PTR_ERR(path->dentry); + goto out_mnt; + } + return 0; +out_mnt: + mntput(path->mnt); +out_err: + return retval; +} + +static int handle_to_path(int mountdirfd, struct file_handle __user *ufh, + struct path *path) +{ + int retval = 0; + struct file_handle f_handle; + struct file_handle *handle = NULL; + + /* + * With handle we don't look at the execute bit on the + * the directory. Ideally we would like CAP_DAC_SEARCH. + * But we don't have that + */ + if (!capable(CAP_DAC_READ_SEARCH)) { + retval = -EPERM; + goto out_err; + } + if (copy_from_user(&f_handle, ufh, sizeof(struct file_handle))) { + retval = -EFAULT; + goto out_err; + } + if ((f_handle.handle_bytes > MAX_HANDLE_SZ) || + (f_handle.handle_bytes == 0)) { + retval = -EINVAL; + goto out_err; + } + handle = kmalloc(sizeof(struct file_handle) + f_handle.handle_bytes, + GFP_KERNEL); + if (!handle) { + retval = -ENOMEM; + goto out_err; + } + /* copy the full handle */ + if (copy_from_user(handle, ufh, + sizeof(struct file_handle) + + f_handle.handle_bytes)) { + retval = -EFAULT; + goto out_handle; + } + + retval = do_handle_to_path(mountdirfd, handle, path); + +out_handle: + kfree(handle); +out_err: + return retval; +} + +long do_handle_open(int mountdirfd, + struct file_handle __user *ufh, int open_flag) +{ + long retval = 0; + struct path path; + struct file *file; + int fd; + + retval = handle_to_path(mountdirfd, ufh, &path); + if (retval) + return retval; + + fd = get_unused_fd_flags(open_flag); + if (fd < 0) { + path_put(&path); + return fd; + } + file = file_open_root(path.dentry, path.mnt, "", open_flag); + if (IS_ERR(file)) { + put_unused_fd(fd); + retval = PTR_ERR(file); + } else { + retval = fd; + fsnotify_open(file); + fd_install(fd, file); + } + path_put(&path); + return retval; +} + +/** + * sys_open_by_handle_at: Open the file handle + * @mountdirfd: directory file descriptor + * @handle: file handle to be opened + * @flag: open flags. + * + * @mountdirfd indicate the directory file descriptor + * of the mount point. file handle is decoded relative + * to the vfsmount pointed by the @mountdirfd. @flags + * value is same as the open(2) flags. + */ +SYSCALL_DEFINE3(open_by_handle_at, int, mountdirfd, + struct file_handle __user *, handle, + int, flags) +{ + long ret; + + if (force_o_largefile()) + flags |= O_LARGEFILE; + + ret = do_handle_open(mountdirfd, handle, flags); + return ret; +} diff --git a/fs/file_table.c b/fs/file_table.c index eb36b6b17e26..74a9544ac770 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -276,11 +276,10 @@ struct file *fget(unsigned int fd) rcu_read_lock(); file = fcheck_files(files, fd); if (file) { - if (!atomic_long_inc_not_zero(&file->f_count)) { - /* File object ref couldn't be taken */ - rcu_read_unlock(); - return NULL; - } + /* File object ref couldn't be taken */ + if (file->f_mode & FMODE_PATH || + !atomic_long_inc_not_zero(&file->f_count)) + file = NULL; } rcu_read_unlock(); @@ -289,6 +288,25 @@ struct file *fget(unsigned int fd) EXPORT_SYMBOL(fget); +struct file *fget_raw(unsigned int fd) +{ + struct file *file; + struct files_struct *files = current->files; + + rcu_read_lock(); + file = fcheck_files(files, fd); + if (file) { + /* File object ref couldn't be taken */ + if (!atomic_long_inc_not_zero(&file->f_count)) + file = NULL; + } + rcu_read_unlock(); + + return file; +} + +EXPORT_SYMBOL(fget_raw); + /* * Lightweight file lookup - no refcnt increment if fd table isn't shared. * @@ -313,6 +331,33 @@ struct file *fget_light(unsigned int fd, int *fput_needed) *fput_needed = 0; if (atomic_read(&files->count) == 1) { file = fcheck_files(files, fd); + if (file && (file->f_mode & FMODE_PATH)) + file = NULL; + } else { + rcu_read_lock(); + file = fcheck_files(files, fd); + if (file) { + if (!(file->f_mode & FMODE_PATH) && + atomic_long_inc_not_zero(&file->f_count)) + *fput_needed = 1; + else + /* Didn't get the reference, someone's freed */ + file = NULL; + } + rcu_read_unlock(); + } + + return file; +} + +struct file *fget_raw_light(unsigned int fd, int *fput_needed) +{ + struct file *file; + struct files_struct *files = current->files; + + *fput_needed = 0; + if (atomic_read(&files->count) == 1) { + file = fcheck_files(files, fd); } else { rcu_read_lock(); file = fcheck_files(files, fd); diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 9e3f68cc1bd1..051b1a084528 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -637,8 +637,10 @@ static int fuse_encode_fh(struct dentry *dentry, u32 *fh, int *max_len, u64 nodeid; u32 generation; - if (*max_len < len) + if (*max_len < len) { + *max_len = len; return 255; + } nodeid = get_fuse_inode(inode)->nodeid; generation = inode->i_generation; diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c index 9023db8184f9..b5a5e60df0d5 100644 --- a/fs/gfs2/export.c +++ b/fs/gfs2/export.c @@ -36,9 +36,13 @@ static int gfs2_encode_fh(struct dentry *dentry, __u32 *p, int *len, struct super_block *sb = inode->i_sb; struct gfs2_inode *ip = GFS2_I(inode); - if (*len < GFS2_SMALL_FH_SIZE || - (connectable && *len < GFS2_LARGE_FH_SIZE)) + if (connectable && (*len < GFS2_LARGE_FH_SIZE)) { + *len = GFS2_LARGE_FH_SIZE; return 255; + } else if (*len < GFS2_SMALL_FH_SIZE) { + *len = GFS2_SMALL_FH_SIZE; + return 255; + } fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32); fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF); diff --git a/fs/internal.h b/fs/internal.h index 9b976b57d7fe..f3d15de44b15 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -106,6 +106,19 @@ extern void put_super(struct super_block *sb); struct nameidata; extern struct file *nameidata_to_filp(struct nameidata *); extern void release_open_intent(struct nameidata *); +struct open_flags { + int open_flag; + int mode; + int acc_mode; + int intent; +}; +extern struct file *do_filp_open(int dfd, const char *pathname, + const struct open_flags *op, int lookup_flags); +extern struct file *do_file_open_root(struct dentry *, struct vfsmount *, + const char *, const struct open_flags *, int lookup_flags); + +extern long do_handle_open(int mountdirfd, + struct file_handle __user *ufh, int open_flag); /* * inode.c diff --git a/fs/isofs/export.c b/fs/isofs/export.c index ed752cb38474..dd4687ff30d0 100644 --- a/fs/isofs/export.c +++ b/fs/isofs/export.c @@ -124,9 +124,13 @@ isofs_export_encode_fh(struct dentry *dentry, * offset of the inode and the upper 16 bits of fh32[1] to * hold the offset of the parent. */ - - if (len < 3 || (connectable && len < 5)) + if (connectable && (len < 5)) { + *max_len = 5; + return 255; + } else if (len < 3) { + *max_len = 3; return 255; + } len = 3; fh32[0] = ei->i_iget5_block; diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c index 5a2b269428a6..3f04a1804931 100644 --- a/fs/jfs/namei.c +++ b/fs/jfs/namei.c @@ -809,9 +809,6 @@ static int jfs_link(struct dentry *old_dentry, if (ip->i_nlink == JFS_LINK_MAX) return -EMLINK; - if (ip->i_nlink == 0) - return -ENOENT; - dquot_initialize(dir); tid = txBegin(ip->i_sb, 0); diff --git a/fs/namei.c b/fs/namei.c index a4689eb2df28..0a601cae23de 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -136,7 +136,7 @@ static int do_getname(const char __user *filename, char *page) return retval; } -char * getname(const char __user * filename) +static char *getname_flags(const char __user * filename, int flags) { char *tmp, *result; @@ -147,14 +147,21 @@ char * getname(const char __user * filename) result = tmp; if (retval < 0) { - __putname(tmp); - result = ERR_PTR(retval); + if (retval != -ENOENT || !(flags & LOOKUP_EMPTY)) { + __putname(tmp); + result = ERR_PTR(retval); + } } } audit_getname(result); return result; } +char *getname(const char __user * filename) +{ + return getname_flags(filename, 0); +} + #ifdef CONFIG_AUDITSYSCALL void putname(const char *name) { @@ -401,9 +408,11 @@ static int nameidata_drop_rcu(struct nameidata *nd) { struct fs_struct *fs = current->fs; struct dentry *dentry = nd->path.dentry; + int want_root = 0; BUG_ON(!(nd->flags & LOOKUP_RCU)); - if (nd->root.mnt) { + if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) { + want_root = 1; spin_lock(&fs->lock); if (nd->root.mnt != fs->root.mnt || nd->root.dentry != fs->root.dentry) @@ -414,7 +423,7 @@ static int nameidata_drop_rcu(struct nameidata *nd) goto err; BUG_ON(nd->inode != dentry->d_inode); spin_unlock(&dentry->d_lock); - if (nd->root.mnt) { + if (want_root) { path_get(&nd->root); spin_unlock(&fs->lock); } @@ -427,7 +436,7 @@ static int nameidata_drop_rcu(struct nameidata *nd) err: spin_unlock(&dentry->d_lock); err_root: - if (nd->root.mnt) + if (want_root) spin_unlock(&fs->lock); return -ECHILD; } @@ -454,9 +463,11 @@ static int nameidata_dentry_drop_rcu(struct nameidata *nd, struct dentry *dentry { struct fs_struct *fs = current->fs; struct dentry *parent = nd->path.dentry; + int want_root = 0; BUG_ON(!(nd->flags & LOOKUP_RCU)); - if (nd->root.mnt) { + if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) { + want_root = 1; spin_lock(&fs->lock); if (nd->root.mnt != fs->root.mnt || nd->root.dentry != fs->root.dentry) @@ -476,7 +487,7 @@ static int nameidata_dentry_drop_rcu(struct nameidata *nd, struct dentry *dentry parent->d_count++; spin_unlock(&dentry->d_lock); spin_unlock(&parent->d_lock); - if (nd->root.mnt) { + if (want_root) { path_get(&nd->root); spin_unlock(&fs->lock); } @@ -490,7 +501,7 @@ err: spin_unlock(&dentry->d_lock); spin_unlock(&parent->d_lock); err_root: - if (nd->root.mnt) + if (want_root) spin_unlock(&fs->lock); return -ECHILD; } @@ -498,8 +509,16 @@ err_root: /* Try to drop out of rcu-walk mode if we were in it, otherwise do nothing. */ static inline int nameidata_dentry_drop_rcu_maybe(struct nameidata *nd, struct dentry *dentry) { - if (nd->flags & LOOKUP_RCU) - return nameidata_dentry_drop_rcu(nd, dentry); + if (nd->flags & LOOKUP_RCU) { + if (unlikely(nameidata_dentry_drop_rcu(nd, dentry))) { + nd->flags &= ~LOOKUP_RCU; + if (!(nd->flags & LOOKUP_ROOT)) + nd->root.mnt = NULL; + rcu_read_unlock(); + br_read_unlock(vfsmount_lock); + return -ECHILD; + } + } return 0; } @@ -518,7 +537,8 @@ static int nameidata_drop_rcu_last(struct nameidata *nd) BUG_ON(!(nd->flags & LOOKUP_RCU)); nd->flags &= ~LOOKUP_RCU; - nd->root.mnt = NULL; + if (!(nd->flags & LOOKUP_ROOT)) + nd->root.mnt = NULL; spin_lock(&dentry->d_lock); if (!__d_rcu_to_refcount(dentry, nd->seq)) goto err_unlock; @@ -539,14 +559,6 @@ err_unlock: return -ECHILD; } -/* Try to drop out of rcu-walk mode if we were in it, otherwise do nothing. */ -static inline int nameidata_drop_rcu_last_maybe(struct nameidata *nd) -{ - if (likely(nd->flags & LOOKUP_RCU)) - return nameidata_drop_rcu_last(nd); - return 0; -} - /** * release_open_intent - free up open intent resources * @nd: pointer to nameidata @@ -590,42 +602,8 @@ do_revalidate(struct dentry *dentry, struct nameidata *nd) return dentry; } -static inline struct dentry * -do_revalidate_rcu(struct dentry *dentry, struct nameidata *nd) -{ - int status = d_revalidate(dentry, nd); - if (likely(status > 0)) - return dentry; - if (status == -ECHILD) { - if (nameidata_dentry_drop_rcu(nd, dentry)) - return ERR_PTR(-ECHILD); - return do_revalidate(dentry, nd); - } - if (status < 0) - return ERR_PTR(status); - /* Don't d_invalidate in rcu-walk mode */ - if (nameidata_dentry_drop_rcu(nd, dentry)) - return ERR_PTR(-ECHILD); - if (!d_invalidate(dentry)) { - dput(dentry); - dentry = NULL; - } - return dentry; -} - -static inline int need_reval_dot(struct dentry *dentry) -{ - if (likely(!(dentry->d_flags & DCACHE_OP_REVALIDATE))) - return 0; - - if (likely(!(dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT))) - return 0; - - return 1; -} - /* - * force_reval_path - force revalidation of a dentry + * handle_reval_path - force revalidation of a dentry * * In some situations the path walking code will trust dentries without * revalidating them. This causes problems for filesystems that depend on @@ -639,27 +617,28 @@ static inline int need_reval_dot(struct dentry *dentry) * invalidate the dentry. It's up to the caller to handle putting references * to the path if necessary. */ -static int -force_reval_path(struct path *path, struct nameidata *nd) +static inline int handle_reval_path(struct nameidata *nd) { + struct dentry *dentry = nd->path.dentry; int status; - struct dentry *dentry = path->dentry; - /* - * only check on filesystems where it's possible for the dentry to - * become stale. - */ - if (!need_reval_dot(dentry)) + if (likely(!(nd->flags & LOOKUP_JUMPED))) + return 0; + + if (likely(!(dentry->d_flags & DCACHE_OP_REVALIDATE))) + return 0; + + if (likely(!(dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT))) return 0; + /* Note: we do not d_invalidate() */ status = d_revalidate(dentry, nd); if (status > 0) return 0; - if (!status) { - d_invalidate(dentry); + if (!status) status = -ESTALE; - } + return status; } @@ -728,6 +707,7 @@ static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *l path_put(&nd->path); nd->path = nd->root; path_get(&nd->root); + nd->flags |= LOOKUP_JUMPED; } nd->inode = nd->path.dentry->d_inode; @@ -757,20 +737,44 @@ static inline void path_to_nameidata(const struct path *path, nd->path.dentry = path->dentry; } +static inline void put_link(struct nameidata *nd, struct path *link, void *cookie) +{ + struct inode *inode = link->dentry->d_inode; + if (!IS_ERR(cookie) && inode->i_op->put_link) + inode->i_op->put_link(link->dentry, nd, cookie); + path_put(link); +} + static __always_inline int -__do_follow_link(const struct path *link, struct nameidata *nd, void **p) +follow_link(struct path *link, struct nameidata *nd, void **p) { int error; struct dentry *dentry = link->dentry; BUG_ON(nd->flags & LOOKUP_RCU); + if (unlikely(current->total_link_count >= 40)) { + *p = ERR_PTR(-ELOOP); /* no ->put_link(), please */ + path_put_conditional(link, nd); + path_put(&nd->path); + return -ELOOP; + } + cond_resched(); + current->total_link_count++; + touch_atime(link->mnt, dentry); nd_set_link(nd, NULL); if (link->mnt == nd->path.mnt) mntget(link->mnt); + error = security_inode_follow_link(link->dentry, nd); + if (error) { + *p = ERR_PTR(error); /* no ->put_link(), please */ + path_put(&nd->path); + return error; + } + nd->last_type = LAST_BIND; *p = dentry->d_inode->i_op->follow_link(dentry, nd); error = PTR_ERR(*p); @@ -780,56 +784,18 @@ __do_follow_link(const struct path *link, struct nameidata *nd, void **p) if (s) error = __vfs_follow_link(nd, s); else if (nd->last_type == LAST_BIND) { - error = force_reval_path(&nd->path, nd); - if (error) + nd->flags |= LOOKUP_JUMPED; + nd->inode = nd->path.dentry->d_inode; + if (nd->inode->i_op->follow_link) { + /* stepped on a _really_ weird one */ path_put(&nd->path); + error = -ELOOP; + } } } return error; } -/* - * This limits recursive symlink follows to 8, while - * limiting consecutive symlinks to 40. - * - * Without that kind of total limit, nasty chains of consecutive - * symlinks can cause almost arbitrarily long lookups. - */ -static inline int do_follow_link(struct inode *inode, struct path *path, struct nameidata *nd) -{ - void *cookie; - int err = -ELOOP; - - /* We drop rcu-walk here */ - if (nameidata_dentry_drop_rcu_maybe(nd, path->dentry)) - return -ECHILD; - BUG_ON(inode != path->dentry->d_inode); - - if (current->link_count >= MAX_NESTED_LINKS) - goto loop; - if (current->total_link_count >= 40) - goto loop; - BUG_ON(nd->depth >= MAX_NESTED_LINKS); - cond_resched(); - err = security_inode_follow_link(path->dentry, nd); - if (err) - goto loop; - current->link_count++; - current->total_link_count++; - nd->depth++; - err = __do_follow_link(path, nd, &cookie); - if (!IS_ERR(cookie) && path->dentry->d_inode->i_op->put_link) - path->dentry->d_inode->i_op->put_link(path->dentry, nd, cookie); - path_put(path); - current->link_count--; - nd->depth--; - return err; -loop: - path_put_conditional(path, nd); - path_put(&nd->path); - return err; -} - static int follow_up_rcu(struct path *path) { struct vfsmount *parent; @@ -1068,7 +1034,7 @@ static int follow_dotdot_rcu(struct nameidata *nd) seq = read_seqcount_begin(&parent->d_seq); if (read_seqcount_retry(&old->d_seq, nd->seq)) - return -ECHILD; + goto failed; inode = parent->d_inode; nd->path.dentry = parent; nd->seq = seq; @@ -1081,8 +1047,15 @@ static int follow_dotdot_rcu(struct nameidata *nd) } __follow_mount_rcu(nd, &nd->path, &inode, true); nd->inode = inode; - return 0; + +failed: + nd->flags &= ~LOOKUP_RCU; + if (!(nd->flags & LOOKUP_ROOT)) + nd->root.mnt = NULL; + rcu_read_unlock(); + br_read_unlock(vfsmount_lock); + return -ECHILD; } /* @@ -1216,68 +1189,85 @@ static int do_lookup(struct nameidata *nd, struct qstr *name, { struct vfsmount *mnt = nd->path.mnt; struct dentry *dentry, *parent = nd->path.dentry; - struct inode *dir; + int need_reval = 1; + int status = 1; int err; /* - * See if the low-level filesystem might want - * to use its own hash.. - */ - if (unlikely(parent->d_flags & DCACHE_OP_HASH)) { - err = parent->d_op->d_hash(parent, nd->inode, name); - if (err < 0) - return err; - } - - /* * Rename seqlock is not required here because in the off chance * of a false negative due to a concurrent rename, we're going to * do the non-racy lookup, below. */ if (nd->flags & LOOKUP_RCU) { unsigned seq; - *inode = nd->inode; dentry = __d_lookup_rcu(parent, name, &seq, inode); - if (!dentry) { - if (nameidata_drop_rcu(nd)) - return -ECHILD; - goto need_lookup; - } + if (!dentry) + goto unlazy; + /* Memory barrier in read_seqcount_begin of child is enough */ if (__read_seqcount_retry(&parent->d_seq, nd->seq)) return -ECHILD; - nd->seq = seq; + if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE)) { - dentry = do_revalidate_rcu(dentry, nd); - if (!dentry) - goto need_lookup; - if (IS_ERR(dentry)) - goto fail; - if (!(nd->flags & LOOKUP_RCU)) - goto done; + status = d_revalidate(dentry, nd); + if (unlikely(status <= 0)) { + if (status != -ECHILD) + need_reval = 0; + goto unlazy; + } } path->mnt = mnt; path->dentry = dentry; if (likely(__follow_mount_rcu(nd, path, inode, false))) return 0; - if (nameidata_drop_rcu(nd)) - return -ECHILD; - /* fallthru */ +unlazy: + if (dentry) { + if (nameidata_dentry_drop_rcu(nd, dentry)) + return -ECHILD; + } else { + if (nameidata_drop_rcu(nd)) + return -ECHILD; + } + } else { + dentry = __d_lookup(parent, name); } - dentry = __d_lookup(parent, name); - if (!dentry) - goto need_lookup; -found: - if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE)) { - dentry = do_revalidate(dentry, nd); - if (!dentry) - goto need_lookup; - if (IS_ERR(dentry)) - goto fail; + +retry: + if (unlikely(!dentry)) { + struct inode *dir = parent->d_inode; + BUG_ON(nd->inode != dir); + + mutex_lock(&dir->i_mutex); + dentry = d_lookup(parent, name); + if (likely(!dentry)) { + dentry = d_alloc_and_lookup(parent, name, nd); + if (IS_ERR(dentry)) { + mutex_unlock(&dir->i_mutex); + return PTR_ERR(dentry); + } + /* known good */ + need_reval = 0; + status = 1; + } + mutex_unlock(&dir->i_mutex); } -done: + if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE) && need_reval) + status = d_revalidate(dentry, nd); + if (unlikely(status <= 0)) { + if (status < 0) { + dput(dentry); + return status; + } + if (!d_invalidate(dentry)) { + dput(dentry); + dentry = NULL; + need_reval = 1; + goto retry; + } + } + path->mnt = mnt; path->dentry = dentry; err = follow_managed(path, nd->flags); @@ -1287,39 +1277,113 @@ done: } *inode = path->dentry->d_inode; return 0; +} -need_lookup: - dir = parent->d_inode; - BUG_ON(nd->inode != dir); +static inline int may_lookup(struct nameidata *nd) +{ + if (nd->flags & LOOKUP_RCU) { + int err = exec_permission(nd->inode, IPERM_FLAG_RCU); + if (err != -ECHILD) + return err; + if (nameidata_drop_rcu(nd)) + return -ECHILD; + } + return exec_permission(nd->inode, 0); +} - mutex_lock(&dir->i_mutex); - /* - * First re-do the cached lookup just in case it was created - * while we waited for the directory semaphore, or the first - * lookup failed due to an unrelated rename. - * - * This could use version numbering or similar to avoid unnecessary - * cache lookups, but then we'd have to do the first lookup in the - * non-racy way. However in the common case here, everything should - * be hot in cache, so would it be a big win? - */ - dentry = d_lookup(parent, name); - if (likely(!dentry)) { - dentry = d_alloc_and_lookup(parent, name, nd); - mutex_unlock(&dir->i_mutex); - if (IS_ERR(dentry)) - goto fail; - goto done; +static inline int handle_dots(struct nameidata *nd, int type) +{ + if (type == LAST_DOTDOT) { + if (nd->flags & LOOKUP_RCU) { + if (follow_dotdot_rcu(nd)) + return -ECHILD; + } else + follow_dotdot(nd); + } + return 0; +} + +static void terminate_walk(struct nameidata *nd) +{ + if (!(nd->flags & LOOKUP_RCU)) { + path_put(&nd->path); + } else { + nd->flags &= ~LOOKUP_RCU; + if (!(nd->flags & LOOKUP_ROOT)) + nd->root.mnt = NULL; + rcu_read_unlock(); + br_read_unlock(vfsmount_lock); } +} + +static inline int walk_component(struct nameidata *nd, struct path *path, + struct qstr *name, int type, int follow) +{ + struct inode *inode; + int err; /* - * Uhhuh! Nasty case: the cache was re-populated while - * we waited on the semaphore. Need to revalidate. + * "." and ".." are special - ".." especially so because it has + * to be able to know about the current root directory and + * parent relationships. */ - mutex_unlock(&dir->i_mutex); - goto found; + if (unlikely(type != LAST_NORM)) + return handle_dots(nd, type); + err = do_lookup(nd, name, path, &inode); + if (unlikely(err)) { + terminate_walk(nd); + return err; + } + if (!inode) { + path_to_nameidata(path, nd); + terminate_walk(nd); + return -ENOENT; + } + if (unlikely(inode->i_op->follow_link) && follow) { + if (nameidata_dentry_drop_rcu_maybe(nd, path->dentry)) + return -ECHILD; + BUG_ON(inode != path->dentry->d_inode); + return 1; + } + path_to_nameidata(path, nd); + nd->inode = inode; + return 0; +} -fail: - return PTR_ERR(dentry); +/* + * This limits recursive symlink follows to 8, while + * limiting consecutive symlinks to 40. + * + * Without that kind of total limit, nasty chains of consecutive + * symlinks can cause almost arbitrarily long lookups. + */ +static inline int nested_symlink(struct path *path, struct nameidata *nd) +{ + int res; + + BUG_ON(nd->depth >= MAX_NESTED_LINKS); + if (unlikely(current->link_count >= MAX_NESTED_LINKS)) { + path_put_conditional(path, nd); + path_put(&nd->path); + return -ELOOP; + } + + nd->depth++; + current->link_count++; + + do { + struct path link = *path; + void *cookie; + + res = follow_link(&link, nd, &cookie); + if (!res) + res = walk_component(nd, path, &nd->last, + nd->last_type, LOOKUP_FOLLOW); + put_link(nd, &link, cookie); + } while (res > 0); + + current->link_count--; + nd->depth--; + return res; } /* @@ -1339,30 +1403,18 @@ static int link_path_walk(const char *name, struct nameidata *nd) while (*name=='/') name++; if (!*name) - goto return_reval; - - if (nd->depth) - lookup_flags = LOOKUP_FOLLOW | (nd->flags & LOOKUP_CONTINUE); + return 0; /* At this point we know we have a real path component. */ for(;;) { - struct inode *inode; unsigned long hash; struct qstr this; unsigned int c; + int type; nd->flags |= LOOKUP_CONTINUE; - if (nd->flags & LOOKUP_RCU) { - err = exec_permission(nd->inode, IPERM_FLAG_RCU); - if (err == -ECHILD) { - if (nameidata_drop_rcu(nd)) - return -ECHILD; - goto exec_again; - } - } else { -exec_again: - err = exec_permission(nd->inode, 0); - } + + err = may_lookup(nd); if (err) break; @@ -1378,52 +1430,43 @@ exec_again: this.len = name - (const char *) this.name; this.hash = end_name_hash(hash); + type = LAST_NORM; + if (this.name[0] == '.') switch (this.len) { + case 2: + if (this.name[1] == '.') { + type = LAST_DOTDOT; + nd->flags |= LOOKUP_JUMPED; + } + break; + case 1: + type = LAST_DOT; + } + if (likely(type == LAST_NORM)) { + struct dentry *parent = nd->path.dentry; + nd->flags &= ~LOOKUP_JUMPED; + if (unlikely(parent->d_flags & DCACHE_OP_HASH)) { + err = parent->d_op->d_hash(parent, nd->inode, + &this); + if (err < 0) + break; + } + } + /* remove trailing slashes? */ if (!c) goto last_component; while (*++name == '/'); if (!*name) - goto last_with_slashes; + goto last_component; - /* - * "." and ".." are special - ".." especially so because it has - * to be able to know about the current root directory and - * parent relationships. - */ - if (this.name[0] == '.') switch (this.len) { - default: - break; - case 2: - if (this.name[1] != '.') - break; - if (nd->flags & LOOKUP_RCU) { - if (follow_dotdot_rcu(nd)) - return -ECHILD; - } else - follow_dotdot(nd); - /* fallthrough */ - case 1: - continue; - } - /* This does the actual lookups.. */ - err = do_lookup(nd, &this, &next, &inode); - if (err) - break; - err = -ENOENT; - if (!inode) - goto out_dput; + err = walk_component(nd, &next, &this, type, LOOKUP_FOLLOW); + if (err < 0) + return err; - if (inode->i_op->follow_link) { - err = do_follow_link(inode, &next, nd); + if (err) { + err = nested_symlink(&next, nd); if (err) - goto return_err; - nd->inode = nd->path.dentry->d_inode; - err = -ENOENT; - if (!nd->inode) - break; - } else { - path_to_nameidata(&next, nd); - nd->inode = inode; + return err; } err = -ENOTDIR; if (!nd->inode->i_op->lookup) @@ -1431,210 +1474,109 @@ exec_again: continue; /* here ends the main loop */ -last_with_slashes: - lookup_flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY; last_component: /* Clear LOOKUP_CONTINUE iff it was previously unset */ nd->flags &= lookup_flags | ~LOOKUP_CONTINUE; - if (lookup_flags & LOOKUP_PARENT) - goto lookup_parent; - if (this.name[0] == '.') switch (this.len) { - default: - break; - case 2: - if (this.name[1] != '.') - break; - if (nd->flags & LOOKUP_RCU) { - if (follow_dotdot_rcu(nd)) - return -ECHILD; - } else - follow_dotdot(nd); - /* fallthrough */ - case 1: - goto return_reval; - } - err = do_lookup(nd, &this, &next, &inode); - if (err) - break; - if (inode && unlikely(inode->i_op->follow_link) && - (lookup_flags & LOOKUP_FOLLOW)) { - err = do_follow_link(inode, &next, nd); - if (err) - goto return_err; - nd->inode = nd->path.dentry->d_inode; - } else { - path_to_nameidata(&next, nd); - nd->inode = inode; - } - err = -ENOENT; - if (!nd->inode) - break; - if (lookup_flags & LOOKUP_DIRECTORY) { - err = -ENOTDIR; - if (!nd->inode->i_op->lookup) - break; - } - goto return_base; -lookup_parent: nd->last = this; - nd->last_type = LAST_NORM; - if (this.name[0] != '.') - goto return_base; - if (this.len == 1) - nd->last_type = LAST_DOT; - else if (this.len == 2 && this.name[1] == '.') - nd->last_type = LAST_DOTDOT; - else - goto return_base; -return_reval: - /* - * We bypassed the ordinary revalidation routines. - * We may need to check the cached dentry for staleness. - */ - if (need_reval_dot(nd->path.dentry)) { - if (nameidata_drop_rcu_last_maybe(nd)) - return -ECHILD; - /* Note: we do not d_invalidate() */ - err = d_revalidate(nd->path.dentry, nd); - if (!err) - err = -ESTALE; - if (err < 0) - break; - return 0; - } -return_base: - if (nameidata_drop_rcu_last_maybe(nd)) - return -ECHILD; + nd->last_type = type; return 0; -out_dput: - if (!(nd->flags & LOOKUP_RCU)) - path_put_conditional(&next, nd); - break; } - if (!(nd->flags & LOOKUP_RCU)) - path_put(&nd->path); -return_err: + terminate_walk(nd); return err; } -static inline int path_walk_rcu(const char *name, struct nameidata *nd) -{ - current->total_link_count = 0; - - return link_path_walk(name, nd); -} - -static inline int path_walk_simple(const char *name, struct nameidata *nd) -{ - current->total_link_count = 0; - - return link_path_walk(name, nd); -} - -static int path_walk(const char *name, struct nameidata *nd) -{ - struct path save = nd->path; - int result; - - current->total_link_count = 0; - - /* make sure the stuff we saved doesn't go away */ - path_get(&save); - - result = link_path_walk(name, nd); - if (result == -ESTALE) { - /* nd->path had been dropped */ - current->total_link_count = 0; - nd->path = save; - nd->inode = save.dentry->d_inode; - path_get(&nd->path); - nd->flags |= LOOKUP_REVAL; - result = link_path_walk(name, nd); - } - - path_put(&save); - - return result; -} - -static void path_finish_rcu(struct nameidata *nd) -{ - if (nd->flags & LOOKUP_RCU) { - /* RCU dangling. Cancel it. */ - nd->flags &= ~LOOKUP_RCU; - nd->root.mnt = NULL; - rcu_read_unlock(); - br_read_unlock(vfsmount_lock); - } - if (nd->file) - fput(nd->file); -} - -static int path_init_rcu(int dfd, const char *name, unsigned int flags, struct nameidata *nd) +static int path_init(int dfd, const char *name, unsigned int flags, + struct nameidata *nd, struct file **fp) { int retval = 0; int fput_needed; struct file *file; nd->last_type = LAST_ROOT; /* if there are only slashes... */ - nd->flags = flags | LOOKUP_RCU; + nd->flags = flags | LOOKUP_JUMPED; nd->depth = 0; + if (flags & LOOKUP_ROOT) { + struct inode *inode = nd->root.dentry->d_inode; + if (*name) { + if (!inode->i_op->lookup) + return -ENOTDIR; + retval = inode_permission(inode, MAY_EXEC); + if (retval) + return retval; + } + nd->path = nd->root; + nd->inode = inode; + if (flags & LOOKUP_RCU) { + br_read_lock(vfsmount_lock); + rcu_read_lock(); + nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq); + } else { + path_get(&nd->path); + } + return 0; + } + nd->root.mnt = NULL; - nd->file = NULL; if (*name=='/') { - struct fs_struct *fs = current->fs; - unsigned seq; - - br_read_lock(vfsmount_lock); - rcu_read_lock(); - - do { - seq = read_seqcount_begin(&fs->seq); - nd->root = fs->root; - nd->path = nd->root; - nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq); - } while (read_seqcount_retry(&fs->seq, seq)); - + if (flags & LOOKUP_RCU) { + br_read_lock(vfsmount_lock); + rcu_read_lock(); + set_root_rcu(nd); + } else { + set_root(nd); + path_get(&nd->root); + } + nd->path = nd->root; } else if (dfd == AT_FDCWD) { - struct fs_struct *fs = current->fs; - unsigned seq; - - br_read_lock(vfsmount_lock); - rcu_read_lock(); + if (flags & LOOKUP_RCU) { + struct fs_struct *fs = current->fs; + unsigned seq; - do { - seq = read_seqcount_begin(&fs->seq); - nd->path = fs->pwd; - nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq); - } while (read_seqcount_retry(&fs->seq, seq)); + br_read_lock(vfsmount_lock); + rcu_read_lock(); + do { + seq = read_seqcount_begin(&fs->seq); + nd->path = fs->pwd; + nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq); + } while (read_seqcount_retry(&fs->seq, seq)); + } else { + get_fs_pwd(current->fs, &nd->path); + } } else { struct dentry *dentry; - file = fget_light(dfd, &fput_needed); + file = fget_raw_light(dfd, &fput_needed); retval = -EBADF; if (!file) goto out_fail; dentry = file->f_path.dentry; - retval = -ENOTDIR; - if (!S_ISDIR(dentry->d_inode->i_mode)) - goto fput_fail; + if (*name) { + retval = -ENOTDIR; + if (!S_ISDIR(dentry->d_inode->i_mode)) + goto fput_fail; - retval = file_permission(file, MAY_EXEC); - if (retval) - goto fput_fail; + retval = file_permission(file, MAY_EXEC); + if (retval) + goto fput_fail; + } nd->path = file->f_path; - if (fput_needed) - nd->file = file; - - nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq); - br_read_lock(vfsmount_lock); - rcu_read_lock(); + if (flags & LOOKUP_RCU) { + if (fput_needed) + *fp = file; + nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq); + br_read_lock(vfsmount_lock); + rcu_read_lock(); + } else { + path_get(&file->f_path); + fput_light(file, fput_needed); + } } + nd->inode = nd->path.dentry->d_inode; return 0; @@ -1644,60 +1586,23 @@ out_fail: return retval; } -static int path_init(int dfd, const char *name, unsigned int flags, struct nameidata *nd) +static inline int lookup_last(struct nameidata *nd, struct path *path) { - int retval = 0; - int fput_needed; - struct file *file; - - nd->last_type = LAST_ROOT; /* if there are only slashes... */ - nd->flags = flags; - nd->depth = 0; - nd->root.mnt = NULL; - - if (*name=='/') { - set_root(nd); - nd->path = nd->root; - path_get(&nd->root); - } else if (dfd == AT_FDCWD) { - get_fs_pwd(current->fs, &nd->path); - } else { - struct dentry *dentry; - - file = fget_light(dfd, &fput_needed); - retval = -EBADF; - if (!file) - goto out_fail; - - dentry = file->f_path.dentry; - - retval = -ENOTDIR; - if (!S_ISDIR(dentry->d_inode->i_mode)) - goto fput_fail; - - retval = file_permission(file, MAY_EXEC); - if (retval) - goto fput_fail; - - nd->path = file->f_path; - path_get(&file->f_path); + if (nd->last_type == LAST_NORM && nd->last.name[nd->last.len]) + nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY; - fput_light(file, fput_needed); - } - nd->inode = nd->path.dentry->d_inode; - return 0; - -fput_fail: - fput_light(file, fput_needed); -out_fail: - return retval; + nd->flags &= ~LOOKUP_PARENT; + return walk_component(nd, path, &nd->last, nd->last_type, + nd->flags & LOOKUP_FOLLOW); } /* Returns 0 and nd will be valid on success; Retuns error, otherwise. */ -static int do_path_lookup(int dfd, const char *name, +static int path_lookupat(int dfd, const char *name, unsigned int flags, struct nameidata *nd) { - int retval; + struct file *base = NULL; + struct path path; + int err; /* * Path walking is largely split up into 2 different synchronisation @@ -1713,44 +1618,75 @@ static int do_path_lookup(int dfd, const char *name, * be handled by restarting a traditional ref-walk (which will always * be able to complete). */ - retval = path_init_rcu(dfd, name, flags, nd); - if (unlikely(retval)) - return retval; - retval = path_walk_rcu(name, nd); - path_finish_rcu(nd); - if (nd->root.mnt) { - path_put(&nd->root); - nd->root.mnt = NULL; + err = path_init(dfd, name, flags | LOOKUP_PARENT, nd, &base); + + if (unlikely(err)) + return err; + + current->total_link_count = 0; + err = link_path_walk(name, nd); + + if (!err && !(flags & LOOKUP_PARENT)) { + err = lookup_last(nd, &path); + while (err > 0) { + void *cookie; + struct path link = path; + nd->flags |= LOOKUP_PARENT; + err = follow_link(&link, nd, &cookie); + if (!err) + err = lookup_last(nd, &path); + put_link(nd, &link, cookie); + } } - if (unlikely(retval == -ECHILD || retval == -ESTALE)) { - /* slower, locked walk */ - if (retval == -ESTALE) - flags |= LOOKUP_REVAL; - retval = path_init(dfd, name, flags, nd); - if (unlikely(retval)) - return retval; - retval = path_walk(name, nd); - if (nd->root.mnt) { - path_put(&nd->root); - nd->root.mnt = NULL; + if (nd->flags & LOOKUP_RCU) { + /* went all way through without dropping RCU */ + BUG_ON(err); + if (nameidata_drop_rcu_last(nd)) + err = -ECHILD; + } + + if (!err) + err = handle_reval_path(nd); + + if (!err && nd->flags & LOOKUP_DIRECTORY) { + if (!nd->inode->i_op->lookup) { + path_put(&nd->path); + return -ENOTDIR; } } + if (base) + fput(base); + + if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) { + path_put(&nd->root); + nd->root.mnt = NULL; + } + return err; +} + +static int do_path_lookup(int dfd, const char *name, + unsigned int flags, struct nameidata *nd) +{ + int retval = path_lookupat(dfd, name, flags | LOOKUP_RCU, nd); + if (unlikely(retval == -ECHILD)) + retval = path_lookupat(dfd, name, flags, nd); + if (unlikely(retval == -ESTALE)) + retval = path_lookupat(dfd, name, flags | LOOKUP_REVAL, nd); + if (likely(!retval)) { if (unlikely(!audit_dummy_context())) { if (nd->path.dentry && nd->inode) audit_inode(name, nd->path.dentry); } } - return retval; } -int path_lookup(const char *name, unsigned int flags, - struct nameidata *nd) +int kern_path_parent(const char *name, struct nameidata *nd) { - return do_path_lookup(AT_FDCWD, name, flags, nd); + return do_path_lookup(AT_FDCWD, name, LOOKUP_PARENT, nd); } int kern_path(const char *name, unsigned int flags, struct path *path) @@ -1774,29 +1710,10 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt, const char *name, unsigned int flags, struct nameidata *nd) { - int retval; - - /* same as do_path_lookup */ - nd->last_type = LAST_ROOT; - nd->flags = flags; - nd->depth = 0; - - nd->path.dentry = dentry; - nd->path.mnt = mnt; - path_get(&nd->path); - nd->root = nd->path; - path_get(&nd->root); - nd->inode = nd->path.dentry->d_inode; - - retval = path_walk(name, nd); - if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry && - nd->inode)) - audit_inode(name, nd->path.dentry); - - path_put(&nd->root); - nd->root.mnt = NULL; - - return retval; + nd->root.dentry = dentry; + nd->root.mnt = mnt; + /* the first argument of do_path_lookup() is ignored with LOOKUP_ROOT */ + return do_path_lookup(AT_FDCWD, name, flags | LOOKUP_ROOT, nd); } static struct dentry *__lookup_hash(struct qstr *name, @@ -1811,17 +1728,6 @@ static struct dentry *__lookup_hash(struct qstr *name, return ERR_PTR(err); /* - * See if the low-level filesystem might want - * to use its own hash.. - */ - if (base->d_flags & DCACHE_OP_HASH) { - err = base->d_op->d_hash(base, inode, name); - dentry = ERR_PTR(err); - if (err < 0) - goto out; - } - - /* * Don't bother with __d_lookup: callers are for creat as * well as unlink, so a lot of the time it would cost * a double lookup. @@ -1833,7 +1739,7 @@ static struct dentry *__lookup_hash(struct qstr *name, if (!dentry) dentry = d_alloc_and_lookup(base, name, nd); -out: + return dentry; } @@ -1847,28 +1753,6 @@ static struct dentry *lookup_hash(struct nameidata *nd) return __lookup_hash(&nd->last, nd->path.dentry, nd); } -static int __lookup_one_len(const char *name, struct qstr *this, - struct dentry *base, int len) -{ - unsigned long hash; - unsigned int c; - - this->name = name; - this->len = len; - if (!len) - return -EACCES; - - hash = init_name_hash(); - while (len--) { - c = *(const unsigned char *)name++; - if (c == '/' || c == '\0') - return -EACCES; - hash = partial_name_hash(c, hash); - } - this->hash = end_name_hash(hash); - return 0; -} - /** * lookup_one_len - filesystem helper to lookup single pathname component * @name: pathname component to lookup @@ -1882,14 +1766,34 @@ static int __lookup_one_len(const char *name, struct qstr *this, */ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len) { - int err; struct qstr this; + unsigned long hash; + unsigned int c; WARN_ON_ONCE(!mutex_is_locked(&base->d_inode->i_mutex)); - err = __lookup_one_len(name, &this, base, len); - if (err) - return ERR_PTR(err); + this.name = name; + this.len = len; + if (!len) + return ERR_PTR(-EACCES); + + hash = init_name_hash(); + while (len--) { + c = *(const unsigned char *)name++; + if (c == '/' || c == '\0') + return ERR_PTR(-EACCES); + hash = partial_name_hash(c, hash); + } + this.hash = end_name_hash(hash); + /* + * See if the low-level filesystem might want + * to use its own hash.. + */ + if (base->d_flags & DCACHE_OP_HASH) { + int err = base->d_op->d_hash(base, base->d_inode, &this); + if (err < 0) + return ERR_PTR(err); + } return __lookup_hash(&this, base, NULL); } @@ -1898,7 +1802,7 @@ int user_path_at(int dfd, const char __user *name, unsigned flags, struct path *path) { struct nameidata nd; - char *tmp = getname(name); + char *tmp = getname_flags(name, flags); int err = PTR_ERR(tmp); if (!IS_ERR(tmp)) { @@ -2078,12 +1982,16 @@ int vfs_create(struct inode *dir, struct dentry *dentry, int mode, return error; } -int may_open(struct path *path, int acc_mode, int flag) +static int may_open(struct path *path, int acc_mode, int flag) { struct dentry *dentry = path->dentry; struct inode *inode = dentry->d_inode; int error; + /* O_PATH? */ + if (!acc_mode) + return 0; + if (!inode) return -ENOENT; @@ -2152,34 +2060,6 @@ static int handle_truncate(struct file *filp) } /* - * Be careful about ever adding any more callers of this - * function. Its flags must be in the namei format, not - * what get passed to sys_open(). - */ -static int __open_namei_create(struct nameidata *nd, struct path *path, - int open_flag, int mode) -{ - int error; - struct dentry *dir = nd->path.dentry; - - if (!IS_POSIXACL(dir->d_inode)) - mode &= ~current_umask(); - error = security_path_mknod(&nd->path, path->dentry, mode, 0); - if (error) - goto out_unlock; - error = vfs_create(dir->d_inode, path->dentry, mode, nd); -out_unlock: - mutex_unlock(&dir->d_inode->i_mutex); - dput(nd->path.dentry); - nd->path.dentry = path->dentry; - - if (error) - return error; - /* Don't check for write permission, don't truncate */ - return may_open(&nd->path, 0, open_flag & ~O_TRUNC); -} - -/* * Note that while the flag value (low two bits) for sys_open means: * 00 - read-only * 01 - write-only @@ -2203,126 +2083,115 @@ static inline int open_to_namei_flags(int flag) return flag; } -static int open_will_truncate(int flag, struct inode *inode) -{ - /* - * We'll never write to the fs underlying - * a device file. - */ - if (special_file(inode->i_mode)) - return 0; - return (flag & O_TRUNC); -} - -static struct file *finish_open(struct nameidata *nd, - int open_flag, int acc_mode) -{ - struct file *filp; - int will_truncate; - int error; - - will_truncate = open_will_truncate(open_flag, nd->path.dentry->d_inode); - if (will_truncate) { - error = mnt_want_write(nd->path.mnt); - if (error) - goto exit; - } - error = may_open(&nd->path, acc_mode, open_flag); - if (error) { - if (will_truncate) - mnt_drop_write(nd->path.mnt); - goto exit; - } - filp = nameidata_to_filp(nd); - if (!IS_ERR(filp)) { - error = ima_file_check(filp, acc_mode); - if (error) { - fput(filp); - filp = ERR_PTR(error); - } - } - if (!IS_ERR(filp)) { - if (will_truncate) { - error = handle_truncate(filp); - if (error) { - fput(filp); - filp = ERR_PTR(error); - } - } - } - /* - * It is now safe to drop the mnt write - * because the filp has had a write taken - * on its behalf. - */ - if (will_truncate) - mnt_drop_write(nd->path.mnt); - path_put(&nd->path); - return filp; - -exit: - path_put(&nd->path); - return ERR_PTR(error); -} - /* - * Handle O_CREAT case for do_filp_open + * Handle the last step of open() */ static struct file *do_last(struct nameidata *nd, struct path *path, - int open_flag, int acc_mode, - int mode, const char *pathname) + const struct open_flags *op, const char *pathname) { struct dentry *dir = nd->path.dentry; + struct dentry *dentry; + int open_flag = op->open_flag; + int will_truncate = open_flag & O_TRUNC; + int want_write = 0; + int acc_mode = op->acc_mode; struct file *filp; - int error = -EISDIR; + int error; + + nd->flags &= ~LOOKUP_PARENT; + nd->flags |= op->intent; switch (nd->last_type) { case LAST_DOTDOT: - follow_dotdot(nd); - dir = nd->path.dentry; case LAST_DOT: - if (need_reval_dot(dir)) { - int status = d_revalidate(nd->path.dentry, nd); - if (!status) - status = -ESTALE; - if (status < 0) { - error = status; - goto exit; - } - } + error = handle_dots(nd, nd->last_type); + if (error) + return ERR_PTR(error); /* fallthrough */ case LAST_ROOT: - goto exit; + if (nd->flags & LOOKUP_RCU) { + if (nameidata_drop_rcu_last(nd)) + return ERR_PTR(-ECHILD); + } + error = handle_reval_path(nd); + if (error) + goto exit; + audit_inode(pathname, nd->path.dentry); + if (open_flag & O_CREAT) { + error = -EISDIR; + goto exit; + } + goto ok; case LAST_BIND: + /* can't be RCU mode here */ + error = handle_reval_path(nd); + if (error) + goto exit; audit_inode(pathname, dir); goto ok; } + if (!(open_flag & O_CREAT)) { + int symlink_ok = 0; + if (nd->last.name[nd->last.len]) + nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY; + if (open_flag & O_PATH && !(nd->flags & LOOKUP_FOLLOW)) + symlink_ok = 1; + /* we _can_ be in RCU mode here */ + error = walk_component(nd, path, &nd->last, LAST_NORM, + !symlink_ok); + if (error < 0) + return ERR_PTR(error); + if (error) /* symlink */ + return NULL; + /* sayonara */ + if (nd->flags & LOOKUP_RCU) { + if (nameidata_drop_rcu_last(nd)) + return ERR_PTR(-ECHILD); + } + + error = -ENOTDIR; + if (nd->flags & LOOKUP_DIRECTORY) { + if (!nd->inode->i_op->lookup) + goto exit; + } + audit_inode(pathname, nd->path.dentry); + goto ok; + } + + /* create side of things */ + + if (nd->flags & LOOKUP_RCU) { + if (nameidata_drop_rcu_last(nd)) + return ERR_PTR(-ECHILD); + } + + audit_inode(pathname, dir); + error = -EISDIR; /* trailing slashes? */ if (nd->last.name[nd->last.len]) goto exit; mutex_lock(&dir->d_inode->i_mutex); - path->dentry = lookup_hash(nd); - path->mnt = nd->path.mnt; - - error = PTR_ERR(path->dentry); - if (IS_ERR(path->dentry)) { + dentry = lookup_hash(nd); + error = PTR_ERR(dentry); + if (IS_ERR(dentry)) { mutex_unlock(&dir->d_inode->i_mutex); goto exit; } - if (IS_ERR(nd->intent.open.file)) { - error = PTR_ERR(nd->intent.open.file); - goto exit_mutex_unlock; - } + path->dentry = dentry; + path->mnt = nd->path.mnt; /* Negative dentry, just create the file */ - if (!path->dentry->d_inode) { + if (!dentry->d_inode) { + int mode = op->mode; + if (!IS_POSIXACL(dir->d_inode)) + mode &= ~current_umask(); /* * This write is needed to ensure that a - * ro->rw transition does not occur between + * rw->ro transition does not occur between * the time when the file is created and when * a permanent write count is taken through * the 'struct file' in nameidata_to_filp(). @@ -2330,22 +2199,21 @@ static struct file *do_last(struct nameidata *nd, struct path *path, error = mnt_want_write(nd->path.mnt); if (error) goto exit_mutex_unlock; - error = __open_namei_create(nd, path, open_flag, mode); - if (error) { - mnt_drop_write(nd->path.mnt); - goto exit; - } - filp = nameidata_to_filp(nd); - mnt_drop_write(nd->path.mnt); - path_put(&nd->path); - if (!IS_ERR(filp)) { - error = ima_file_check(filp, acc_mode); - if (error) { - fput(filp); - filp = ERR_PTR(error); - } - } - return filp; + want_write = 1; + /* Don't check for write permission, don't truncate */ + open_flag &= ~O_TRUNC; + will_truncate = 0; + acc_mode = MAY_OPEN; + error = security_path_mknod(&nd->path, dentry, mode, 0); + if (error) + goto exit_mutex_unlock; + error = vfs_create(dir->d_inode, dentry, mode, nd); + if (error) + goto exit_mutex_unlock; + mutex_unlock(&dir->d_inode->i_mutex); + dput(nd->path.dentry); + nd->path.dentry = dentry; + goto common; } /* @@ -2375,7 +2243,40 @@ static struct file *do_last(struct nameidata *nd, struct path *path, if (S_ISDIR(nd->inode->i_mode)) goto exit; ok: - filp = finish_open(nd, open_flag, acc_mode); + if (!S_ISREG(nd->inode->i_mode)) + will_truncate = 0; + + if (will_truncate) { + error = mnt_want_write(nd->path.mnt); + if (error) + goto exit; + want_write = 1; + } +common: + error = may_open(&nd->path, acc_mode, open_flag); + if (error) + goto exit; + filp = nameidata_to_filp(nd); + if (!IS_ERR(filp)) { + error = ima_file_check(filp, op->acc_mode); + if (error) { + fput(filp); + filp = ERR_PTR(error); + } + } + if (!IS_ERR(filp)) { + if (will_truncate) { + error = handle_truncate(filp); + if (error) { + fput(filp); + filp = ERR_PTR(error); + } + } + } +out: + if (want_write) + mnt_drop_write(nd->path.mnt); + path_put(&nd->path); return filp; exit_mutex_unlock: @@ -2383,204 +2284,103 @@ exit_mutex_unlock: exit_dput: path_put_conditional(path, nd); exit: - path_put(&nd->path); - return ERR_PTR(error); + filp = ERR_PTR(error); + goto out; } -/* - * Note that the low bits of the passed in "open_flag" - * are not the same as in the local variable "flag". See - * open_to_namei_flags() for more details. - */ -struct file *do_filp_open(int dfd, const char *pathname, - int open_flag, int mode, int acc_mode) +static struct file *path_openat(int dfd, const char *pathname, + struct nameidata *nd, const struct open_flags *op, int flags) { + struct file *base = NULL; struct file *filp; - struct nameidata nd; - int error; struct path path; - int count = 0; - int flag = open_to_namei_flags(open_flag); - int flags; - - if (!(open_flag & O_CREAT)) - mode = 0; - - /* Must never be set by userspace */ - open_flag &= ~FMODE_NONOTIFY; - - /* - * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only - * check for O_DSYNC if the need any syncing at all we enforce it's - * always set instead of having to deal with possibly weird behaviour - * for malicious applications setting only __O_SYNC. - */ - if (open_flag & __O_SYNC) - open_flag |= O_DSYNC; - - if (!acc_mode) - acc_mode = MAY_OPEN | ACC_MODE(open_flag); - - /* O_TRUNC implies we need access checks for write permissions */ - if (open_flag & O_TRUNC) - acc_mode |= MAY_WRITE; - - /* Allow the LSM permission hook to distinguish append - access from general write access. */ - if (open_flag & O_APPEND) - acc_mode |= MAY_APPEND; - - flags = LOOKUP_OPEN; - if (open_flag & O_CREAT) { - flags |= LOOKUP_CREATE; - if (open_flag & O_EXCL) - flags |= LOOKUP_EXCL; - } - if (open_flag & O_DIRECTORY) - flags |= LOOKUP_DIRECTORY; - if (!(open_flag & O_NOFOLLOW)) - flags |= LOOKUP_FOLLOW; + int error; filp = get_empty_filp(); if (!filp) return ERR_PTR(-ENFILE); - filp->f_flags = open_flag; - nd.intent.open.file = filp; - nd.intent.open.flags = flag; - nd.intent.open.create_mode = mode; + filp->f_flags = op->open_flag; + nd->intent.open.file = filp; + nd->intent.open.flags = open_to_namei_flags(op->open_flag); + nd->intent.open.create_mode = op->mode; - if (open_flag & O_CREAT) - goto creat; - - /* !O_CREAT, simple open */ - error = do_path_lookup(dfd, pathname, flags, &nd); + error = path_init(dfd, pathname, flags | LOOKUP_PARENT, nd, &base); if (unlikely(error)) - goto out_filp2; - error = -ELOOP; - if (!(nd.flags & LOOKUP_FOLLOW)) { - if (nd.inode->i_op->follow_link) - goto out_path2; - } - error = -ENOTDIR; - if (nd.flags & LOOKUP_DIRECTORY) { - if (!nd.inode->i_op->lookup) - goto out_path2; - } - audit_inode(pathname, nd.path.dentry); - filp = finish_open(&nd, open_flag, acc_mode); -out2: - release_open_intent(&nd); - return filp; - -out_path2: - path_put(&nd.path); -out_filp2: - filp = ERR_PTR(error); - goto out2; - -creat: - /* OK, have to create the file. Find the parent. */ - error = path_init_rcu(dfd, pathname, - LOOKUP_PARENT | (flags & LOOKUP_REVAL), &nd); - if (error) goto out_filp; - error = path_walk_rcu(pathname, &nd); - path_finish_rcu(&nd); - if (unlikely(error == -ECHILD || error == -ESTALE)) { - /* slower, locked walk */ - if (error == -ESTALE) { -reval: - flags |= LOOKUP_REVAL; - } - error = path_init(dfd, pathname, - LOOKUP_PARENT | (flags & LOOKUP_REVAL), &nd); - if (error) - goto out_filp; - error = path_walk_simple(pathname, &nd); - } + current->total_link_count = 0; + error = link_path_walk(pathname, nd); if (unlikely(error)) goto out_filp; - if (unlikely(!audit_dummy_context())) - audit_inode(pathname, nd.path.dentry); - /* - * We have the parent and last component. - */ - nd.flags = flags; - filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname); + filp = do_last(nd, &path, op, pathname); while (unlikely(!filp)) { /* trailing symlink */ struct path link = path; - struct inode *linki = link.dentry->d_inode; void *cookie; - error = -ELOOP; - if (!(nd.flags & LOOKUP_FOLLOW)) - goto exit_dput; - if (count++ == 32) - goto exit_dput; - /* - * This is subtle. Instead of calling do_follow_link() we do - * the thing by hands. The reason is that this way we have zero - * link_count and path_walk() (called from ->follow_link) - * honoring LOOKUP_PARENT. After that we have the parent and - * last component, i.e. we are in the same situation as after - * the first path_walk(). Well, almost - if the last component - * is normal we get its copy stored in nd->last.name and we will - * have to putname() it when we are done. Procfs-like symlinks - * just set LAST_BIND. - */ - nd.flags |= LOOKUP_PARENT; - error = security_inode_follow_link(link.dentry, &nd); - if (error) - goto exit_dput; - error = __do_follow_link(&link, &nd, &cookie); - if (unlikely(error)) { - if (!IS_ERR(cookie) && linki->i_op->put_link) - linki->i_op->put_link(link.dentry, &nd, cookie); - /* nd.path had been dropped */ - nd.path = link; - goto out_path; + if (!(nd->flags & LOOKUP_FOLLOW)) { + path_put_conditional(&path, nd); + path_put(&nd->path); + filp = ERR_PTR(-ELOOP); + break; } - nd.flags &= ~LOOKUP_PARENT; - filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname); - if (linki->i_op->put_link) - linki->i_op->put_link(link.dentry, &nd, cookie); - path_put(&link); + nd->flags |= LOOKUP_PARENT; + nd->flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL); + error = follow_link(&link, nd, &cookie); + if (unlikely(error)) + filp = ERR_PTR(error); + else + filp = do_last(nd, &path, op, pathname); + put_link(nd, &link, cookie); } out: - if (nd.root.mnt) - path_put(&nd.root); - if (filp == ERR_PTR(-ESTALE) && !(flags & LOOKUP_REVAL)) - goto reval; - release_open_intent(&nd); + if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) + path_put(&nd->root); + if (base) + fput(base); + release_open_intent(nd); return filp; -exit_dput: - path_put_conditional(&path, &nd); -out_path: - path_put(&nd.path); out_filp: filp = ERR_PTR(error); goto out; } -/** - * filp_open - open file and return file pointer - * - * @filename: path to open - * @flags: open flags as per the open(2) second argument - * @mode: mode for the new file if O_CREAT is set, else ignored - * - * This is the helper to open a file from kernelspace if you really - * have to. But in generally you should not do this, so please move - * along, nothing to see here.. - */ -struct file *filp_open(const char *filename, int flags, int mode) +struct file *do_filp_open(int dfd, const char *pathname, + const struct open_flags *op, int flags) +{ + struct nameidata nd; + struct file *filp; + + filp = path_openat(dfd, pathname, &nd, op, flags | LOOKUP_RCU); + if (unlikely(filp == ERR_PTR(-ECHILD))) + filp = path_openat(dfd, pathname, &nd, op, flags); + if (unlikely(filp == ERR_PTR(-ESTALE))) + filp = path_openat(dfd, pathname, &nd, op, flags | LOOKUP_REVAL); + return filp; +} + +struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt, + const char *name, const struct open_flags *op, int flags) { - return do_filp_open(AT_FDCWD, filename, flags, mode, 0); + struct nameidata nd; + struct file *file; + + nd.root.mnt = mnt; + nd.root.dentry = dentry; + + flags |= LOOKUP_ROOT; + + if (dentry->d_inode->i_op->follow_link && op->intent & LOOKUP_OPEN) + return ERR_PTR(-ELOOP); + + file = path_openat(-1, name, &nd, op, flags | LOOKUP_RCU); + if (unlikely(file == ERR_PTR(-ECHILD))) + file = path_openat(-1, name, &nd, op, flags); + if (unlikely(file == ERR_PTR(-ESTALE))) + file = path_openat(-1, name, &nd, op, flags | LOOKUP_REVAL); + return file; } -EXPORT_SYMBOL(filp_open); /** * lookup_create - lookup a dentry, creating it if it doesn't exist @@ -3119,7 +2919,11 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de return error; mutex_lock(&inode->i_mutex); - error = dir->i_op->link(old_dentry, dir, new_dentry); + /* Make sure we don't allow creating hardlink to an unlinked file */ + if (inode->i_nlink == 0) + error = -ENOENT; + else + error = dir->i_op->link(old_dentry, dir, new_dentry); mutex_unlock(&inode->i_mutex); if (!error) fsnotify_link(dir, inode, new_dentry); @@ -3141,15 +2945,27 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, struct dentry *new_dentry; struct nameidata nd; struct path old_path; + int how = 0; int error; char *to; - if ((flags & ~AT_SYMLINK_FOLLOW) != 0) + if ((flags & ~(AT_SYMLINK_FOLLOW | AT_EMPTY_PATH)) != 0) return -EINVAL; + /* + * To use null names we require CAP_DAC_READ_SEARCH + * This ensures that not everyone will be able to create + * handlink using the passed filedescriptor. + */ + if (flags & AT_EMPTY_PATH) { + if (!capable(CAP_DAC_READ_SEARCH)) + return -ENOENT; + how = LOOKUP_EMPTY; + } + + if (flags & AT_SYMLINK_FOLLOW) + how |= LOOKUP_FOLLOW; - error = user_path_at(olddfd, oldname, - flags & AT_SYMLINK_FOLLOW ? LOOKUP_FOLLOW : 0, - &old_path); + error = user_path_at(olddfd, oldname, how, &old_path); if (error) return error; @@ -3586,7 +3402,7 @@ EXPORT_SYMBOL(page_readlink); EXPORT_SYMBOL(__page_symlink); EXPORT_SYMBOL(page_symlink); EXPORT_SYMBOL(page_symlink_inode_operations); -EXPORT_SYMBOL(path_lookup); +EXPORT_SYMBOL(kern_path_parent); EXPORT_SYMBOL(kern_path); EXPORT_SYMBOL(vfs_path_lookup); EXPORT_SYMBOL(inode_permission); diff --git a/fs/namespace.c b/fs/namespace.c index d1edf26025dc..dffe6f49ab93 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1002,6 +1002,18 @@ const struct seq_operations mounts_op = { .show = show_vfsmnt }; +static int uuid_is_nil(u8 *uuid) +{ + int i; + u8 *cp = (u8 *)uuid; + + for (i = 0; i < 16; i++) { + if (*cp++) + return 0; + } + return 1; +} + static int show_mountinfo(struct seq_file *m, void *v) { struct proc_mounts *p = m->private; @@ -1040,6 +1052,10 @@ static int show_mountinfo(struct seq_file *m, void *v) if (IS_MNT_UNBINDABLE(mnt)) seq_puts(m, " unbindable"); + if (!uuid_is_nil(mnt->mnt_sb->s_uuid)) + /* print the uuid */ + seq_printf(m, " uuid:%pU", mnt->mnt_sb->s_uuid); + /* Filesystem specific data */ seq_puts(m, " - "); show_type(m, sb); diff --git a/fs/nfsctl.c b/fs/nfsctl.c index bf9cbd242ddd..124e8fcb0dd6 100644 --- a/fs/nfsctl.c +++ b/fs/nfsctl.c @@ -22,30 +22,17 @@ static struct file *do_open(char *name, int flags) { - struct nameidata nd; struct vfsmount *mnt; - int error; + struct file *file; mnt = do_kern_mount("nfsd", 0, "nfsd", NULL); if (IS_ERR(mnt)) return (struct file *)mnt; - error = vfs_path_lookup(mnt->mnt_root, mnt, name, 0, &nd); - mntput(mnt); /* drop do_kern_mount reference */ - if (error) - return ERR_PTR(error); - - if (flags == O_RDWR) - error = may_open(&nd.path, MAY_READ|MAY_WRITE, flags); - else - error = may_open(&nd.path, MAY_WRITE, flags); + file = file_open_root(mnt->mnt_root, mnt, name, flags); - if (!error) - return dentry_open(nd.path.dentry, nd.path.mnt, flags, - current_cred()); - - path_put(&nd.path); - return ERR_PTR(error); + mntput(mnt); /* drop do_kern_mount reference */ + return file; } static struct { diff --git a/fs/ocfs2/export.c b/fs/ocfs2/export.c index 5dbc3062b4fd..254652a9b542 100644 --- a/fs/ocfs2/export.c +++ b/fs/ocfs2/export.c @@ -197,8 +197,12 @@ static int ocfs2_encode_fh(struct dentry *dentry, u32 *fh_in, int *max_len, dentry->d_name.len, dentry->d_name.name, fh, len, connectable); - if (len < 3 || (connectable && len < 6)) { - mlog(ML_ERROR, "fh buffer is too small for encoding\n"); + if (connectable && (len < 6)) { + *max_len = 6; + type = 255; + goto bail; + } else if (len < 3) { + *max_len = 3; type = 255; goto bail; } diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c index 19ebc5aad391..29623da133cc 100644 --- a/fs/ocfs2/refcounttree.c +++ b/fs/ocfs2/refcounttree.c @@ -4379,7 +4379,7 @@ static int ocfs2_user_path_parent(const char __user *path, if (IS_ERR(s)) return PTR_ERR(s); - error = path_lookup(s, LOOKUP_PARENT, nd); + error = kern_path_parent(s, nd); if (error) putname(s); else diff --git a/fs/open.c b/fs/open.c index b47aab39c057..3cac0bda46df 100644 --- a/fs/open.c +++ b/fs/open.c @@ -573,13 +573,15 @@ SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, { struct path path; int error = -EINVAL; - int follow; + int lookup_flags; - if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) + if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) goto out; - follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; - error = user_path_at(dfd, filename, follow, &path); + lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; + if (flag & AT_EMPTY_PATH) + lookup_flags |= LOOKUP_EMPTY; + error = user_path_at(dfd, filename, lookup_flags, &path); if (error) goto out; error = mnt_want_write(path.mnt); @@ -669,11 +671,16 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, int (*open)(struct inode *, struct file *), const struct cred *cred) { + static const struct file_operations empty_fops = {}; struct inode *inode; int error; f->f_mode = OPEN_FMODE(f->f_flags) | FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE; + + if (unlikely(f->f_flags & O_PATH)) + f->f_mode = FMODE_PATH; + inode = dentry->d_inode; if (f->f_mode & FMODE_WRITE) { error = __get_file_write_access(inode, mnt); @@ -687,9 +694,15 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, f->f_path.dentry = dentry; f->f_path.mnt = mnt; f->f_pos = 0; - f->f_op = fops_get(inode->i_fop); file_sb_list_add(f, inode->i_sb); + if (unlikely(f->f_mode & FMODE_PATH)) { + f->f_op = &empty_fops; + return f; + } + + f->f_op = fops_get(inode->i_fop); + error = security_dentry_open(f, cred); if (error) goto cleanup_all; @@ -890,15 +903,110 @@ void fd_install(unsigned int fd, struct file *file) EXPORT_SYMBOL(fd_install); +static inline int build_open_flags(int flags, int mode, struct open_flags *op) +{ + int lookup_flags = 0; + int acc_mode; + + if (!(flags & O_CREAT)) + mode = 0; + op->mode = mode; + + /* Must never be set by userspace */ + flags &= ~FMODE_NONOTIFY; + + /* + * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only + * check for O_DSYNC if the need any syncing at all we enforce it's + * always set instead of having to deal with possibly weird behaviour + * for malicious applications setting only __O_SYNC. + */ + if (flags & __O_SYNC) + flags |= O_DSYNC; + + /* + * If we have O_PATH in the open flag. Then we + * cannot have anything other than the below set of flags + */ + if (flags & O_PATH) { + flags &= O_DIRECTORY | O_NOFOLLOW | O_PATH; + acc_mode = 0; + } else { + acc_mode = MAY_OPEN | ACC_MODE(flags); + } + + op->open_flag = flags; + + /* O_TRUNC implies we need access checks for write permissions */ + if (flags & O_TRUNC) + acc_mode |= MAY_WRITE; + + /* Allow the LSM permission hook to distinguish append + access from general write access. */ + if (flags & O_APPEND) + acc_mode |= MAY_APPEND; + + op->acc_mode = acc_mode; + + op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN; + + if (flags & O_CREAT) { + op->intent |= LOOKUP_CREATE; + if (flags & O_EXCL) + op->intent |= LOOKUP_EXCL; + } + + if (flags & O_DIRECTORY) + lookup_flags |= LOOKUP_DIRECTORY; + if (!(flags & O_NOFOLLOW)) + lookup_flags |= LOOKUP_FOLLOW; + return lookup_flags; +} + +/** + * filp_open - open file and return file pointer + * + * @filename: path to open + * @flags: open flags as per the open(2) second argument + * @mode: mode for the new file if O_CREAT is set, else ignored + * + * This is the helper to open a file from kernelspace if you really + * have to. But in generally you should not do this, so please move + * along, nothing to see here.. + */ +struct file *filp_open(const char *filename, int flags, int mode) +{ + struct open_flags op; + int lookup = build_open_flags(flags, mode, &op); + return do_filp_open(AT_FDCWD, filename, &op, lookup); +} +EXPORT_SYMBOL(filp_open); + +struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt, + const char *filename, int flags) +{ + struct open_flags op; + int lookup = build_open_flags(flags, 0, &op); + if (flags & O_CREAT) + return ERR_PTR(-EINVAL); + if (!filename && (flags & O_DIRECTORY)) + if (!dentry->d_inode->i_op->lookup) + return ERR_PTR(-ENOTDIR); + return do_file_open_root(dentry, mnt, filename, &op, lookup); +} +EXPORT_SYMBOL(file_open_root); + long do_sys_open(int dfd, const char __user *filename, int flags, int mode) { + struct open_flags op; + int lookup = build_open_flags(flags, mode, &op); char *tmp = getname(filename); int fd = PTR_ERR(tmp); if (!IS_ERR(tmp)) { fd = get_unused_fd_flags(flags); if (fd >= 0) { - struct file *f = do_filp_open(dfd, tmp, flags, mode, 0); + struct file *f = do_filp_open(dfd, tmp, &op, lookup); if (IS_ERR(f)) { put_unused_fd(fd); fd = PTR_ERR(f); @@ -968,8 +1076,10 @@ int filp_close(struct file *filp, fl_owner_t id) if (filp->f_op && filp->f_op->flush) retval = filp->f_op->flush(filp, id); - dnotify_flush(filp, id); - locks_remove_posix(filp, id); + if (likely(!(filp->f_mode & FMODE_PATH))) { + dnotify_flush(filp, id); + locks_remove_posix(filp, id); + } fput(filp); return retval; } diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c index 0bae036831e2..1bba24bad820 100644 --- a/fs/reiserfs/inode.c +++ b/fs/reiserfs/inode.c @@ -1593,8 +1593,13 @@ int reiserfs_encode_fh(struct dentry *dentry, __u32 * data, int *lenp, struct inode *inode = dentry->d_inode; int maxlen = *lenp; - if (maxlen < 3) + if (need_parent && (maxlen < 5)) { + *lenp = 5; return 255; + } else if (maxlen < 3) { + *lenp = 3; + return 255; + } data[0] = inode->i_ino; data[1] = le32_to_cpu(INODE_PKEY(inode)->k_dir_id); diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c index 68fdf45cc6c9..4b2eb564fdad 100644 --- a/fs/reiserfs/namei.c +++ b/fs/reiserfs/namei.c @@ -1122,10 +1122,6 @@ static int reiserfs_link(struct dentry *old_dentry, struct inode *dir, reiserfs_write_unlock(dir->i_sb); return -EMLINK; } - if (inode->i_nlink == 0) { - reiserfs_write_unlock(dir->i_sb); - return -ENOENT; - } /* inc before scheduling so reiserfs_unlink knows we are here */ inc_nlink(inode); diff --git a/fs/stat.c b/fs/stat.c index d5c61cf2b703..961039121cb8 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -75,13 +75,16 @@ int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat, int error = -EINVAL; int lookup_flags = 0; - if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT)) != 0) + if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | + AT_EMPTY_PATH)) != 0) goto out; if (!(flag & AT_SYMLINK_NOFOLLOW)) lookup_flags |= LOOKUP_FOLLOW; if (flag & AT_NO_AUTOMOUNT) lookup_flags |= LOOKUP_NO_AUTOMOUNT; + if (flag & AT_EMPTY_PATH) + lookup_flags |= LOOKUP_EMPTY; error = user_path_at(dfd, filename, lookup_flags, &path); if (error) @@ -297,7 +300,7 @@ SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname, if (bufsiz <= 0) return -EINVAL; - error = user_path_at(dfd, pathname, 0, &path); + error = user_path_at(dfd, pathname, LOOKUP_EMPTY, &path); if (!error) { struct inode *inode = path.dentry->d_inode; diff --git a/fs/statfs.c b/fs/statfs.c index 30ea8c8a996b..8244924dec55 100644 --- a/fs/statfs.c +++ b/fs/statfs.c @@ -73,149 +73,135 @@ int vfs_statfs(struct path *path, struct kstatfs *buf) } EXPORT_SYMBOL(vfs_statfs); -static int do_statfs_native(struct path *path, struct statfs *buf) +int user_statfs(const char __user *pathname, struct kstatfs *st) { - struct kstatfs st; - int retval; + struct path path; + int error = user_path(pathname, &path); + if (!error) { + error = vfs_statfs(&path, st); + path_put(&path); + } + return error; +} - retval = vfs_statfs(path, &st); - if (retval) - return retval; +int fd_statfs(int fd, struct kstatfs *st) +{ + struct file *file = fget(fd); + int error = -EBADF; + if (file) { + error = vfs_statfs(&file->f_path, st); + fput(file); + } + return error; +} - if (sizeof(*buf) == sizeof(st)) - memcpy(buf, &st, sizeof(st)); +static int do_statfs_native(struct kstatfs *st, struct statfs __user *p) +{ + struct statfs buf; + + if (sizeof(buf) == sizeof(*st)) + memcpy(&buf, st, sizeof(*st)); else { - if (sizeof buf->f_blocks == 4) { - if ((st.f_blocks | st.f_bfree | st.f_bavail | - st.f_bsize | st.f_frsize) & + if (sizeof buf.f_blocks == 4) { + if ((st->f_blocks | st->f_bfree | st->f_bavail | + st->f_bsize | st->f_frsize) & 0xffffffff00000000ULL) return -EOVERFLOW; /* * f_files and f_ffree may be -1; it's okay to stuff * that into 32 bits */ - if (st.f_files != -1 && - (st.f_files & 0xffffffff00000000ULL)) + if (st->f_files != -1 && + (st->f_files & 0xffffffff00000000ULL)) return -EOVERFLOW; - if (st.f_ffree != -1 && - (st.f_ffree & 0xffffffff00000000ULL)) + if (st->f_ffree != -1 && + (st->f_ffree & 0xffffffff00000000ULL)) return -EOVERFLOW; } - buf->f_type = st.f_type; - buf->f_bsize = st.f_bsize; - buf->f_blocks = st.f_blocks; - buf->f_bfree = st.f_bfree; - buf->f_bavail = st.f_bavail; - buf->f_files = st.f_files; - buf->f_ffree = st.f_ffree; - buf->f_fsid = st.f_fsid; - buf->f_namelen = st.f_namelen; - buf->f_frsize = st.f_frsize; - buf->f_flags = st.f_flags; - memset(buf->f_spare, 0, sizeof(buf->f_spare)); + buf.f_type = st->f_type; + buf.f_bsize = st->f_bsize; + buf.f_blocks = st->f_blocks; + buf.f_bfree = st->f_bfree; + buf.f_bavail = st->f_bavail; + buf.f_files = st->f_files; + buf.f_ffree = st->f_ffree; + buf.f_fsid = st->f_fsid; + buf.f_namelen = st->f_namelen; + buf.f_frsize = st->f_frsize; + buf.f_flags = st->f_flags; + memset(buf.f_spare, 0, sizeof(buf.f_spare)); } + if (copy_to_user(p, &buf, sizeof(buf))) + return -EFAULT; return 0; } -static int do_statfs64(struct path *path, struct statfs64 *buf) +static int do_statfs64(struct kstatfs *st, struct statfs64 __user *p) { - struct kstatfs st; - int retval; - - retval = vfs_statfs(path, &st); - if (retval) - return retval; - - if (sizeof(*buf) == sizeof(st)) - memcpy(buf, &st, sizeof(st)); + struct statfs64 buf; + if (sizeof(buf) == sizeof(*st)) + memcpy(&buf, st, sizeof(*st)); else { - buf->f_type = st.f_type; - buf->f_bsize = st.f_bsize; - buf->f_blocks = st.f_blocks; - buf->f_bfree = st.f_bfree; - buf->f_bavail = st.f_bavail; - buf->f_files = st.f_files; - buf->f_ffree = st.f_ffree; - buf->f_fsid = st.f_fsid; - buf->f_namelen = st.f_namelen; - buf->f_frsize = st.f_frsize; - buf->f_flags = st.f_flags; - memset(buf->f_spare, 0, sizeof(buf->f_spare)); + buf.f_type = st->f_type; + buf.f_bsize = st->f_bsize; + buf.f_blocks = st->f_blocks; + buf.f_bfree = st->f_bfree; + buf.f_bavail = st->f_bavail; + buf.f_files = st->f_files; + buf.f_ffree = st->f_ffree; + buf.f_fsid = st->f_fsid; + buf.f_namelen = st->f_namelen; + buf.f_frsize = st->f_frsize; + buf.f_flags = st->f_flags; + memset(buf.f_spare, 0, sizeof(buf.f_spare)); } + if (copy_to_user(p, &buf, sizeof(buf))) + return -EFAULT; return 0; } SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct statfs __user *, buf) { - struct path path; - int error; - - error = user_path(pathname, &path); - if (!error) { - struct statfs tmp; - error = do_statfs_native(&path, &tmp); - if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) - error = -EFAULT; - path_put(&path); - } + struct kstatfs st; + int error = user_statfs(pathname, &st); + if (!error) + error = do_statfs_native(&st, buf); return error; } SYSCALL_DEFINE3(statfs64, const char __user *, pathname, size_t, sz, struct statfs64 __user *, buf) { - struct path path; - long error; - + struct kstatfs st; + int error; if (sz != sizeof(*buf)) return -EINVAL; - error = user_path(pathname, &path); - if (!error) { - struct statfs64 tmp; - error = do_statfs64(&path, &tmp); - if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) - error = -EFAULT; - path_put(&path); - } + error = user_statfs(pathname, &st); + if (!error) + error = do_statfs64(&st, buf); return error; } SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct statfs __user *, buf) { - struct file *file; - struct statfs tmp; - int error; - - error = -EBADF; - file = fget(fd); - if (!file) - goto out; - error = do_statfs_native(&file->f_path, &tmp); - if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) - error = -EFAULT; - fput(file); -out: + struct kstatfs st; + int error = fd_statfs(fd, &st); + if (!error) + error = do_statfs_native(&st, buf); return error; } SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user *, buf) { - struct file *file; - struct statfs64 tmp; + struct kstatfs st; int error; if (sz != sizeof(*buf)) return -EINVAL; - error = -EBADF; - file = fget(fd); - if (!file) - goto out; - error = do_statfs64(&file->f_path, &tmp); - if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) - error = -EFAULT; - fput(file); -out: + error = fd_statfs(fd, &st); + if (!error) + error = do_statfs64(&st, buf); return error; } diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 14f64b689d7f..7217d67a80a6 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -522,24 +522,6 @@ static int ubifs_link(struct dentry *old_dentry, struct inode *dir, ubifs_assert(mutex_is_locked(&dir->i_mutex)); ubifs_assert(mutex_is_locked(&inode->i_mutex)); - /* - * Return -ENOENT if we've raced with unlink and i_nlink is 0. Doing - * otherwise has the potential to corrupt the orphan inode list. - * - * Indeed, consider a scenario when 'vfs_link(dirA/fileA)' and - * 'vfs_unlink(dirA/fileA, dirB/fileB)' race. 'vfs_link()' does not - * lock 'dirA->i_mutex', so this is possible. Both of the functions - * lock 'fileA->i_mutex' though. Suppose 'vfs_unlink()' wins, and takes - * 'fileA->i_mutex' mutex first. Suppose 'fileA->i_nlink' is 1. In this - * case 'ubifs_unlink()' will drop the last reference, and put 'inodeA' - * to the list of orphans. After this, 'vfs_link()' will link - * 'dirB/fileB' to 'inodeA'. This is a problem because, for example, - * the subsequent 'vfs_unlink(dirB/fileB)' will add the same inode - * to the list of orphans. - */ - if (inode->i_nlink == 0) - return -ENOENT; - err = dbg_check_synced_i_size(inode); if (err) return err; diff --git a/fs/udf/namei.c b/fs/udf/namei.c index b7c338d5e9df..f1dce848ef96 100644 --- a/fs/udf/namei.c +++ b/fs/udf/namei.c @@ -1286,8 +1286,13 @@ static int udf_encode_fh(struct dentry *de, __u32 *fh, int *lenp, struct fid *fid = (struct fid *)fh; int type = FILEID_UDF_WITHOUT_PARENT; - if (len < 3 || (connectable && len < 5)) + if (connectable && (len < 5)) { + *lenp = 5; + return 255; + } else if (len < 3) { + *lenp = 3; return 255; + } *lenp = 3; fid->udf.block = location.logicalBlockNum; diff --git a/fs/xfs/linux-2.6/xfs_export.c b/fs/xfs/linux-2.6/xfs_export.c index fc0114da7fdd..f4f878fc0083 100644 --- a/fs/xfs/linux-2.6/xfs_export.c +++ b/fs/xfs/linux-2.6/xfs_export.c @@ -89,8 +89,10 @@ xfs_fs_encode_fh( * seven combinations work. The real answer is "don't use v2". */ len = xfs_fileid_length(fileid_type); - if (*max_len < len) + if (*max_len < len) { + *max_len = len; return 255; + } *max_len = len; switch (fileid_type) { diff --git a/include/asm-generic/fcntl.h b/include/asm-generic/fcntl.h index 0fc16e3f0bfc..84793c7025e2 100644 --- a/include/asm-generic/fcntl.h +++ b/include/asm-generic/fcntl.h @@ -80,6 +80,10 @@ #define O_SYNC (__O_SYNC|O_DSYNC) #endif +#ifndef O_PATH +#define O_PATH 010000000 +#endif + #ifndef O_NDELAY #define O_NDELAY O_NONBLOCK #endif diff --git a/include/asm-generic/unistd.h b/include/asm-generic/unistd.h index b969770196c2..57af0338d270 100644 --- a/include/asm-generic/unistd.h +++ b/include/asm-generic/unistd.h @@ -646,9 +646,13 @@ __SYSCALL(__NR_prlimit64, sys_prlimit64) __SYSCALL(__NR_fanotify_init, sys_fanotify_init) #define __NR_fanotify_mark 263 __SYSCALL(__NR_fanotify_mark, sys_fanotify_mark) +#define __NR_name_to_handle_at 264 +__SYSCALL(__NR_name_to_handle_at, sys_name_to_handle_at) +#define __NR_open_by_handle_at 265 +__SYSCALL(__NR_open_by_handle_at, sys_open_by_handle_at) #undef __NR_syscalls -#define __NR_syscalls 264 +#define __NR_syscalls 266 /* * All syscalls below here should go away really, diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h index 28028988c862..33a42f24b275 100644 --- a/include/linux/exportfs.h +++ b/include/linux/exportfs.h @@ -8,6 +8,9 @@ struct inode; struct super_block; struct vfsmount; +/* limit the handle size to NFSv4 handle size now */ +#define MAX_HANDLE_SZ 128 + /* * The fileid_type identifies how the file within the filesystem is encoded. * In theory this is freely set and parsed by the filesystem, but we try to @@ -121,8 +124,10 @@ struct fid { * set, the encode_fh() should store sufficient information so that a good * attempt can be made to find not only the file but also it's place in the * filesystem. This typically means storing a reference to de->d_parent in - * the filehandle fragment. encode_fh() should return the number of bytes - * stored or a negative error code such as %-ENOSPC + * the filehandle fragment. encode_fh() should return the fileid_type on + * success and on error returns 255 (if the space needed to encode fh is + * greater than @max_len*4 bytes). On error @max_len contains the minimum + * size(in 4 byte unit) needed to encode the file handle. * * fh_to_dentry: * @fh_to_dentry is given a &struct super_block (@sb) and a file handle diff --git a/include/linux/fcntl.h b/include/linux/fcntl.h index a562fa5fb4e3..f550f894ba15 100644 --- a/include/linux/fcntl.h +++ b/include/linux/fcntl.h @@ -46,6 +46,7 @@ unlinking file. */ #define AT_SYMLINK_FOLLOW 0x400 /* Follow symbolic links. */ #define AT_NO_AUTOMOUNT 0x800 /* Suppress terminal automount traversal */ +#define AT_EMPTY_PATH 0x1000 /* Allow empty relative pathname */ #ifdef __KERNEL__ diff --git a/include/linux/file.h b/include/linux/file.h index e85baebf6279..21a79958541c 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -29,6 +29,8 @@ static inline void fput_light(struct file *file, int fput_needed) extern struct file *fget(unsigned int fd); extern struct file *fget_light(unsigned int fd, int *fput_needed); +extern struct file *fget_raw(unsigned int fd); +extern struct file *fget_raw_light(unsigned int fd, int *fput_needed); extern void set_close_on_exec(unsigned int fd, int flag); extern void put_filp(struct file *); extern int alloc_fd(unsigned start, unsigned flags); diff --git a/include/linux/fs.h b/include/linux/fs.h index e38b50a4b9d2..13df14e2c42e 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -102,6 +102,9 @@ struct inodes_stat_t { /* File is huge (eg. /dev/kmem): treat loff_t as unsigned */ #define FMODE_UNSIGNED_OFFSET ((__force fmode_t)0x2000) +/* File is opened with O_PATH; almost nothing can be done with it */ +#define FMODE_PATH ((__force fmode_t)0x4000) + /* File was opened by fanotify and shouldn't generate fanotify events */ #define FMODE_NONOTIFY ((__force fmode_t)0x1000000) @@ -978,6 +981,13 @@ struct file { #endif }; +struct file_handle { + __u32 handle_bytes; + int handle_type; + /* file identifier */ + unsigned char f_handle[0]; +}; + #define get_file(x) atomic_long_inc(&(x)->f_count) #define fput_atomic(x) atomic_long_add_unless(&(x)->f_count, -1, 1) #define file_count(x) atomic_long_read(&(x)->f_count) @@ -1401,6 +1411,7 @@ struct super_block { wait_queue_head_t s_wait_unfrozen; char s_id[32]; /* Informational name */ + u8 s_uuid[16]; /* UUID */ void *s_fs_info; /* Filesystem private info */ fmode_t s_mode; @@ -1874,6 +1885,8 @@ extern void drop_collected_mounts(struct vfsmount *); extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *, struct vfsmount *); extern int vfs_statfs(struct path *, struct kstatfs *); +extern int user_statfs(const char __user *, struct kstatfs *); +extern int fd_statfs(int, struct kstatfs *); extern int statfs_by_dentry(struct dentry *, struct kstatfs *); extern int freeze_super(struct super_block *super); extern int thaw_super(struct super_block *super); @@ -1990,6 +2003,8 @@ extern int do_fallocate(struct file *file, int mode, loff_t offset, extern long do_sys_open(int dfd, const char __user *filename, int flags, int mode); extern struct file *filp_open(const char *, int, int); +extern struct file *file_open_root(struct dentry *, struct vfsmount *, + const char *, int); extern struct file * dentry_open(struct dentry *, struct vfsmount *, int, const struct cred *); extern int filp_close(struct file *, fl_owner_t id); @@ -2205,10 +2220,6 @@ extern struct file *create_read_pipe(struct file *f, int flags); extern struct file *create_write_pipe(int flags); extern void free_write_pipe(struct file *); -extern struct file *do_filp_open(int dfd, const char *pathname, - int open_flag, int mode, int acc_mode); -extern int may_open(struct path *, int, int); - extern int kernel_read(struct file *, loff_t, char *, unsigned long); extern struct file * open_exec(const char *); diff --git a/include/linux/namei.h b/include/linux/namei.h index f276d4fa01fc..9c8603872c36 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -19,7 +19,6 @@ struct nameidata { struct path path; struct qstr last; struct path root; - struct file *file; struct inode *inode; /* path.dentry.d_inode */ unsigned int flags; unsigned seq; @@ -63,6 +62,10 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND}; #define LOOKUP_EXCL 0x0400 #define LOOKUP_RENAME_TARGET 0x0800 +#define LOOKUP_JUMPED 0x1000 +#define LOOKUP_ROOT 0x2000 +#define LOOKUP_EMPTY 0x4000 + extern int user_path_at(int, const char __user *, unsigned, struct path *); #define user_path(name, path) user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW, path) @@ -72,7 +75,7 @@ extern int user_path_at(int, const char __user *, unsigned, struct path *); extern int kern_path(const char *, unsigned, struct path *); -extern int path_lookup(const char *, unsigned, struct nameidata *); +extern int kern_path_parent(const char *, struct nameidata *); extern int vfs_path_lookup(struct dentry *, struct vfsmount *, const char *, unsigned int, struct nameidata *); diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 98664db1be47..2d9b79c0f224 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -62,6 +62,7 @@ struct robust_list_head; struct getcpu_cache; struct old_linux_dirent; struct perf_event_attr; +struct file_handle; #include <linux/types.h> #include <linux/aio_abi.h> @@ -832,5 +833,10 @@ asmlinkage long sys_mmap_pgoff(unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags, unsigned long fd, unsigned long pgoff); asmlinkage long sys_old_mmap(struct mmap_arg_struct __user *arg); - +asmlinkage long sys_name_to_handle_at(int dfd, const char __user *name, + struct file_handle __user *handle, + int __user *mnt_id, int flag); +asmlinkage long sys_open_by_handle_at(int mountdirfd, + struct file_handle __user *handle, + int flags); #endif diff --git a/init/Kconfig b/init/Kconfig index be788c0957d4..e72fa17fe559 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -287,6 +287,18 @@ config BSD_PROCESS_ACCT_V3 for processing it. A preliminary version of these tools is available at <http://www.gnu.org/software/acct/>. +config FHANDLE + bool "open by fhandle syscalls" + select EXPORTFS + help + If you say Y here, a user level program will be able to map + file names to handle and then later use the handle for + different file system operations. This is useful in implementing + userspace file servers, which now track files using handles instead + of names. The handle would remain the same even if file names + get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2) + syscalls. + config TASKSTATS bool "Export task/process statistics through netlink (EXPERIMENTAL)" depends on NET diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c index d2e3c7866460..e683869365d9 100644 --- a/kernel/audit_watch.c +++ b/kernel/audit_watch.c @@ -144,9 +144,9 @@ int audit_watch_compare(struct audit_watch *watch, unsigned long ino, dev_t dev) } /* Initialize a parent watch entry. */ -static struct audit_parent *audit_init_parent(struct nameidata *ndp) +static struct audit_parent *audit_init_parent(struct path *path) { - struct inode *inode = ndp->path.dentry->d_inode; + struct inode *inode = path->dentry->d_inode; struct audit_parent *parent; int ret; @@ -353,53 +353,40 @@ static void audit_remove_parent_watches(struct audit_parent *parent) } /* Get path information necessary for adding watches. */ -static int audit_get_nd(char *path, struct nameidata **ndp, struct nameidata **ndw) +static int audit_get_nd(struct audit_watch *watch, struct path *parent) { - struct nameidata *ndparent, *ndwatch; + struct nameidata nd; + struct dentry *d; int err; - ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL); - if (unlikely(!ndparent)) - return -ENOMEM; + err = kern_path_parent(watch->path, &nd); + if (err) + return err; - ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL); - if (unlikely(!ndwatch)) { - kfree(ndparent); - return -ENOMEM; + if (nd.last_type != LAST_NORM) { + path_put(&nd.path); + return -EINVAL; } - err = path_lookup(path, LOOKUP_PARENT, ndparent); - if (err) { - kfree(ndparent); - kfree(ndwatch); - return err; + mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); + d = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len); + if (IS_ERR(d)) { + mutex_unlock(&nd.path.dentry->d_inode->i_mutex); + path_put(&nd.path); + return PTR_ERR(d); } - - err = path_lookup(path, 0, ndwatch); - if (err) { - kfree(ndwatch); - ndwatch = NULL; + if (d->d_inode) { + /* update watch filter fields */ + watch->dev = d->d_inode->i_sb->s_dev; + watch->ino = d->d_inode->i_ino; } + mutex_unlock(&nd.path.dentry->d_inode->i_mutex); - *ndp = ndparent; - *ndw = ndwatch; - + *parent = nd.path; + dput(d); return 0; } -/* Release resources used for watch path information. */ -static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw) -{ - if (ndp) { - path_put(&ndp->path); - kfree(ndp); - } - if (ndw) { - path_put(&ndw->path); - kfree(ndw); - } -} - /* Associate the given rule with an existing parent. * Caller must hold audit_filter_mutex. */ static void audit_add_to_parent(struct audit_krule *krule, @@ -440,31 +427,24 @@ int audit_add_watch(struct audit_krule *krule, struct list_head **list) { struct audit_watch *watch = krule->watch; struct audit_parent *parent; - struct nameidata *ndp = NULL, *ndw = NULL; + struct path parent_path; int h, ret = 0; mutex_unlock(&audit_filter_mutex); /* Avoid calling path_lookup under audit_filter_mutex. */ - ret = audit_get_nd(watch->path, &ndp, &ndw); - if (ret) { - /* caller expects mutex locked */ - mutex_lock(&audit_filter_mutex); - goto error; - } + ret = audit_get_nd(watch, &parent_path); + /* caller expects mutex locked */ mutex_lock(&audit_filter_mutex); - /* update watch filter fields */ - if (ndw) { - watch->dev = ndw->path.dentry->d_inode->i_sb->s_dev; - watch->ino = ndw->path.dentry->d_inode->i_ino; - } + if (ret) + return ret; /* either find an old parent or attach a new one */ - parent = audit_find_parent(ndp->path.dentry->d_inode); + parent = audit_find_parent(parent_path.dentry->d_inode); if (!parent) { - parent = audit_init_parent(ndp); + parent = audit_init_parent(&parent_path); if (IS_ERR(parent)) { ret = PTR_ERR(parent); goto error; @@ -479,9 +459,8 @@ int audit_add_watch(struct audit_krule *krule, struct list_head **list) h = audit_hash_ino((u32)watch->ino); *list = &audit_inode_hash[h]; error: - audit_put_nd(ndp, ndw); /* NULL args OK */ + path_put(&parent_path); return ret; - } void audit_remove_watch_rule(struct audit_krule *krule) diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index c782fe9924c7..25cc41cd8f33 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -186,3 +186,8 @@ cond_syscall(sys_perf_event_open); /* fanotify! */ cond_syscall(sys_fanotify_init); cond_syscall(sys_fanotify_mark); + +/* open by handle */ +cond_syscall(sys_name_to_handle_at); +cond_syscall(sys_open_by_handle_at); +cond_syscall(compat_sys_open_by_handle_at); diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c index b875bedf7c9a..3b8e028b9601 100644 --- a/kernel/sysctl_binary.c +++ b/kernel/sysctl_binary.c @@ -1321,13 +1321,11 @@ static ssize_t binary_sysctl(const int *name, int nlen, void __user *oldval, size_t oldlen, void __user *newval, size_t newlen) { const struct bin_table *table = NULL; - struct nameidata nd; struct vfsmount *mnt; struct file *file; ssize_t result; char *pathname; int flags; - int acc_mode; pathname = sysctl_getname(name, nlen, &table); result = PTR_ERR(pathname); @@ -1337,28 +1335,17 @@ static ssize_t binary_sysctl(const int *name, int nlen, /* How should the sysctl be accessed? */ if (oldval && oldlen && newval && newlen) { flags = O_RDWR; - acc_mode = MAY_READ | MAY_WRITE; } else if (newval && newlen) { flags = O_WRONLY; - acc_mode = MAY_WRITE; } else if (oldval && oldlen) { flags = O_RDONLY; - acc_mode = MAY_READ; } else { result = 0; goto out_putname; } mnt = current->nsproxy->pid_ns->proc_mnt; - result = vfs_path_lookup(mnt->mnt_root, mnt, pathname, 0, &nd); - if (result) - goto out_putname; - - result = may_open(&nd.path, acc_mode, flags); - if (result) - goto out_putpath; - - file = dentry_open(nd.path.dentry, nd.path.mnt, flags, current_cred()); + file = file_open_root(mnt->mnt_root, mnt, pathname, flags); result = PTR_ERR(file); if (IS_ERR(file)) goto out_putname; @@ -1370,10 +1357,6 @@ out_putname: putname(pathname); out: return result; - -out_putpath: - path_put(&nd.path); - goto out_putname; } diff --git a/mm/shmem.c b/mm/shmem.c index 5ee67c990602..3437b65d6d6e 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2144,8 +2144,10 @@ static int shmem_encode_fh(struct dentry *dentry, __u32 *fh, int *len, { struct inode *inode = dentry->d_inode; - if (*len < 3) + if (*len < 3) { + *len = 3; return 255; + } if (inode_unhashed(inode)) { /* Unfortunately insert_inode_hash is not idempotent, diff --git a/net/core/scm.c b/net/core/scm.c index bbe454450801..4c1ef026d695 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -95,7 +95,7 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp) int fd = fdp[i]; struct file *file; - if (fd < 0 || !(file = fget(fd))) + if (fd < 0 || !(file = fget_raw(fd))) return -EBADF; *fpp++ = file; fpl->count++; diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 437a99e560e1..ba5b8c208498 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -850,7 +850,7 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) * Get the parent directory, calculate the hash for last * component. */ - err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd); + err = kern_path_parent(sunaddr->sun_path, &nd); if (err) goto out_mknod_parent; diff --git a/net/unix/garbage.c b/net/unix/garbage.c index f89f83bf828e..b6f4b994eb35 100644 --- a/net/unix/garbage.c +++ b/net/unix/garbage.c @@ -104,7 +104,7 @@ struct sock *unix_get_socket(struct file *filp) /* * Socket ? */ - if (S_ISSOCK(inode->i_mode)) { + if (S_ISSOCK(inode->i_mode) && !(filp->f_mode & FMODE_PATH)) { struct socket *sock = SOCKET_I(inode); struct sock *s = sock->sk; |