diff options
| -rw-r--r-- | Documentation/filesystems/overlayfs.txt | 8 | ||||
| -rw-r--r-- | fs/overlayfs/copy_up.c | 2 | ||||
| -rw-r--r-- | fs/overlayfs/dir.c | 58 | ||||
| -rw-r--r-- | fs/overlayfs/inode.c | 108 | ||||
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 17 | ||||
| -rw-r--r-- | fs/overlayfs/readdir.c | 63 | ||||
| -rw-r--r-- | fs/overlayfs/super.c | 93 | ||||
| -rw-r--r-- | include/linux/fs.h | 1 |
8 files changed, 246 insertions, 104 deletions
diff --git a/Documentation/filesystems/overlayfs.txt b/Documentation/filesystems/overlayfs.txt index d6259c786316..bcbf9710e4af 100644 --- a/Documentation/filesystems/overlayfs.txt +++ b/Documentation/filesystems/overlayfs.txt @@ -183,12 +183,10 @@ The copy_up operation essentially creates a new, identical file and moves it over to the old name. The new file may be on a different filesystem, so both st_dev and st_ino of the file may change. -Any open files referring to this inode will access the old data and -metadata. Similarly any file locks obtained before copy_up will not -apply to the copied up file. +Any open files referring to this inode will access the old data. -On a file opened with O_RDONLY fchmod(2), fchown(2), futimesat(2) and -fsetxattr(2) will fail with EROFS. +Any file locks (and leases) obtained before copy_up will not apply +to the copied up file. If a file with multiple hard links is copied up, then this will "break" the link. Changes will not be propagated to other names diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 54e5d6681786..43fdc2765aea 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -80,6 +80,8 @@ int ovl_copy_xattr(struct dentry *old, struct dentry *new) } for (name = buf; name < (buf + list_size); name += strlen(name) + 1) { + if (ovl_is_private_xattr(name)) + continue; retry: size = vfs_getxattr(old, name, value, value_size); if (size == -ERANGE) diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 12bcd07b9e32..1560fdc09a5f 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -12,6 +12,8 @@ #include <linux/xattr.h> #include <linux/security.h> #include <linux/cred.h> +#include <linux/posix_acl.h> +#include <linux/posix_acl_xattr.h> #include "overlayfs.h" void ovl_cleanup(struct inode *wdir, struct dentry *wdentry) @@ -186,6 +188,9 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode, struct dentry *newdentry; int err; + if (!hardlink && !IS_POSIXACL(udir)) + stat->mode &= ~current_umask(); + inode_lock_nested(udir, I_MUTEX_PARENT); newdentry = lookup_one_len(dentry->d_name.name, upperdir, dentry->d_name.len); @@ -335,6 +340,32 @@ out_free: return ret; } +static int ovl_set_upper_acl(struct dentry *upperdentry, const char *name, + const struct posix_acl *acl) +{ + void *buffer; + size_t size; + int err; + + if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !acl) + return 0; + + size = posix_acl_to_xattr(NULL, acl, NULL, 0); + buffer = kmalloc(size, GFP_KERNEL); + if (!buffer) + return -ENOMEM; + + size = posix_acl_to_xattr(&init_user_ns, acl, buffer, size); + err = size; + if (err < 0) + goto out_free; + + err = vfs_setxattr(upperdentry, name, buffer, size, XATTR_CREATE); +out_free: + kfree(buffer); + return err; +} + static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, struct kstat *stat, const char *link, struct dentry *hardlink) @@ -346,10 +377,18 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, struct dentry *upper; struct dentry *newdentry; int err; + struct posix_acl *acl, *default_acl; if (WARN_ON(!workdir)) return -EROFS; + if (!hardlink) { + err = posix_acl_create(dentry->d_parent->d_inode, + &stat->mode, &default_acl, &acl); + if (err) + return err; + } + err = ovl_lock_rename_workdir(workdir, upperdir); if (err) goto out; @@ -384,6 +423,17 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, if (err) goto out_cleanup; } + if (!hardlink) { + err = ovl_set_upper_acl(newdentry, XATTR_NAME_POSIX_ACL_ACCESS, + acl); + if (err) + goto out_cleanup; + + err = ovl_set_upper_acl(newdentry, XATTR_NAME_POSIX_ACL_DEFAULT, + default_acl); + if (err) + goto out_cleanup; + } if (!hardlink && S_ISDIR(stat->mode)) { err = ovl_set_opaque(newdentry); @@ -410,6 +460,10 @@ out_dput: out_unlock: unlock_rename(workdir, upperdir); out: + if (!hardlink) { + posix_acl_release(acl); + posix_acl_release(default_acl); + } return err; out_cleanup: @@ -950,9 +1004,9 @@ const struct inode_operations ovl_dir_inode_operations = { .permission = ovl_permission, .getattr = ovl_dir_getattr, .setxattr = generic_setxattr, - .getxattr = ovl_getxattr, + .getxattr = generic_getxattr, .listxattr = ovl_listxattr, - .removexattr = ovl_removexattr, + .removexattr = generic_removexattr, .get_acl = ovl_get_acl, .update_time = ovl_update_time, }; diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 1b885c156028..c75625c1efa3 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -10,6 +10,7 @@ #include <linux/fs.h> #include <linux/slab.h> #include <linux/xattr.h> +#include <linux/posix_acl.h> #include "overlayfs.h" static int ovl_copy_up_truncate(struct dentry *dentry) @@ -191,32 +192,44 @@ static int ovl_readlink(struct dentry *dentry, char __user *buf, int bufsiz) return err; } -static bool ovl_is_private_xattr(const char *name) +bool ovl_is_private_xattr(const char *name) { -#define OVL_XATTR_PRE_NAME OVL_XATTR_PREFIX "." - return strncmp(name, OVL_XATTR_PRE_NAME, - sizeof(OVL_XATTR_PRE_NAME) - 1) == 0; + return strncmp(name, OVL_XATTR_PREFIX, + sizeof(OVL_XATTR_PREFIX) - 1) == 0; } -int ovl_setxattr(struct dentry *dentry, struct inode *inode, - const char *name, const void *value, - size_t size, int flags) +int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value, + size_t size, int flags) { int err; - struct dentry *upperdentry; + struct path realpath; + enum ovl_path_type type = ovl_path_real(dentry, &realpath); const struct cred *old_cred; err = ovl_want_write(dentry); if (err) goto out; + if (!value && !OVL_TYPE_UPPER(type)) { + err = vfs_getxattr(realpath.dentry, name, NULL, 0); + if (err < 0) + goto out_drop_write; + } + err = ovl_copy_up(dentry); if (err) goto out_drop_write; - upperdentry = ovl_dentry_upper(dentry); + if (!OVL_TYPE_UPPER(type)) + ovl_path_upper(dentry, &realpath); + old_cred = ovl_override_creds(dentry->d_sb); - err = vfs_setxattr(upperdentry, name, value, size, flags); + if (value) + err = vfs_setxattr(realpath.dentry, name, value, size, flags); + else { + WARN_ON(flags != XATTR_REPLACE); + err = vfs_removexattr(realpath.dentry, name); + } revert_creds(old_cred); out_drop_write: @@ -225,16 +238,13 @@ out: return err; } -ssize_t ovl_getxattr(struct dentry *dentry, struct inode *inode, - const char *name, void *value, size_t size) +int ovl_xattr_get(struct dentry *dentry, const char *name, + void *value, size_t size) { struct dentry *realdentry = ovl_dentry_real(dentry); ssize_t res; const struct cred *old_cred; - if (ovl_is_private_xattr(name)) - return -ENODATA; - old_cred = ovl_override_creds(dentry->d_sb); res = vfs_getxattr(realdentry, name, value, size); revert_creds(old_cred); @@ -245,7 +255,8 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size) { struct dentry *realdentry = ovl_dentry_real(dentry); ssize_t res; - int off; + size_t len; + char *s; const struct cred *old_cred; old_cred = ovl_override_creds(dentry->d_sb); @@ -255,73 +266,39 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size) return res; /* filter out private xattrs */ - for (off = 0; off < res;) { - char *s = list + off; - size_t slen = strlen(s) + 1; + for (s = list, len = res; len;) { + size_t slen = strnlen(s, len) + 1; - BUG_ON(off + slen > res); + /* underlying fs providing us with an broken xattr list? */ + if (WARN_ON(slen > len)) + return -EIO; + len -= slen; if (ovl_is_private_xattr(s)) { res -= slen; - memmove(s, s + slen, res - off); + memmove(s, s + slen, len); } else { - off += slen; + s += slen; } } return res; } -int ovl_removexattr(struct dentry *dentry, const char *name) -{ - int err; - struct path realpath; - enum ovl_path_type type = ovl_path_real(dentry, &realpath); - const struct cred *old_cred; - - err = ovl_want_write(dentry); - if (err) - goto out; - - err = -ENODATA; - if (ovl_is_private_xattr(name)) - goto out_drop_write; - - if (!OVL_TYPE_UPPER(type)) { - err = vfs_getxattr(realpath.dentry, name, NULL, 0); - if (err < 0) - goto out_drop_write; - - err = ovl_copy_up(dentry); - if (err) - goto out_drop_write; - - ovl_path_upper(dentry, &realpath); - } - - old_cred = ovl_override_creds(dentry->d_sb); - err = vfs_removexattr(realpath.dentry, name); - revert_creds(old_cred); -out_drop_write: - ovl_drop_write(dentry); -out: - return err; -} - struct posix_acl *ovl_get_acl(struct inode *inode, int type) { struct inode *realinode = ovl_inode_real(inode, NULL); const struct cred *old_cred; struct posix_acl *acl; - if (!IS_POSIXACL(realinode)) + if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !IS_POSIXACL(realinode)) return NULL; if (!realinode->i_op->get_acl) return NULL; old_cred = ovl_override_creds(inode->i_sb); - acl = realinode->i_op->get_acl(realinode, type); + acl = get_acl(realinode, type); revert_creds(old_cred); return acl; @@ -391,9 +368,9 @@ static const struct inode_operations ovl_file_inode_operations = { .permission = ovl_permission, .getattr = ovl_getattr, .setxattr = generic_setxattr, - .getxattr = ovl_getxattr, + .getxattr = generic_getxattr, .listxattr = ovl_listxattr, - .removexattr = ovl_removexattr, + .removexattr = generic_removexattr, .get_acl = ovl_get_acl, .update_time = ovl_update_time, }; @@ -404,9 +381,9 @@ static const struct inode_operations ovl_symlink_inode_operations = { .readlink = ovl_readlink, .getattr = ovl_getattr, .setxattr = generic_setxattr, - .getxattr = ovl_getxattr, + .getxattr = generic_getxattr, .listxattr = ovl_listxattr, - .removexattr = ovl_removexattr, + .removexattr = generic_removexattr, .update_time = ovl_update_time, }; @@ -415,6 +392,9 @@ static void ovl_fill_inode(struct inode *inode, umode_t mode) inode->i_ino = get_next_ino(); inode->i_mode = mode; inode->i_flags |= S_NOCMTIME; +#ifdef CONFIG_FS_POSIX_ACL + inode->i_acl = inode->i_default_acl = ACL_DONT_CACHE; +#endif mode &= S_IFMT; switch (mode) { diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index e4f5c9536bfe..5813ccff8cd9 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -24,8 +24,8 @@ enum ovl_path_type { (OVL_TYPE_MERGE(type) || !OVL_TYPE_UPPER(type)) -#define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay" -#define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX ".opaque" +#define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay." +#define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque" #define OVL_ISUPPER_MASK 1UL @@ -179,20 +179,21 @@ int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list); void ovl_cache_free(struct list_head *list); int ovl_check_d_type_supported(struct path *realpath); +void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt, + struct dentry *dentry, int level); /* inode.c */ int ovl_setattr(struct dentry *dentry, struct iattr *attr); int ovl_permission(struct inode *inode, int mask); -int ovl_setxattr(struct dentry *dentry, struct inode *inode, - const char *name, const void *value, - size_t size, int flags); -ssize_t ovl_getxattr(struct dentry *dentry, struct inode *inode, - const char *name, void *value, size_t size); +int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value, + size_t size, int flags); +int ovl_xattr_get(struct dentry *dentry, const char *name, + void *value, size_t size); ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); -int ovl_removexattr(struct dentry *dentry, const char *name); struct posix_acl *ovl_get_acl(struct inode *inode, int type); int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags); int ovl_update_time(struct inode *inode, struct timespec *ts, int flags); +bool ovl_is_private_xattr(const char *name); struct inode *ovl_new_inode(struct super_block *sb, umode_t mode); struct inode *ovl_get_inode(struct super_block *sb, struct inode *realinode); diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index cf37fc76fc9f..f241b4ee3d8a 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -248,7 +248,7 @@ static inline int ovl_dir_read(struct path *realpath, err = rdd->err; } while (!err && rdd->count); - if (!err && rdd->first_maybe_whiteout) + if (!err && rdd->first_maybe_whiteout && rdd->dentry) err = ovl_check_whiteouts(realpath->dentry, rdd); fput(realfile); @@ -606,3 +606,64 @@ int ovl_check_d_type_supported(struct path *realpath) return rdd.d_type_supported; } + +static void ovl_workdir_cleanup_recurse(struct path *path, int level) +{ + int err; + struct inode *dir = path->dentry->d_inode; + LIST_HEAD(list); + struct ovl_cache_entry *p; + struct ovl_readdir_data rdd = { + .ctx.actor = ovl_fill_merge, + .dentry = NULL, + .list = &list, + .root = RB_ROOT, + .is_lowest = false, + }; + + err = ovl_dir_read(path, &rdd); + if (err) + goto out; + + inode_lock_nested(dir, I_MUTEX_PARENT); + list_for_each_entry(p, &list, l_node) { + struct dentry *dentry; + + if (p->name[0] == '.') { + if (p->len == 1) + continue; + if (p->len == 2 && p->name[1] == '.') + continue; + } + dentry = lookup_one_len(p->name, path->dentry, p->len); + if (IS_ERR(dentry)) + continue; + if (dentry->d_inode) + ovl_workdir_cleanup(dir, path->mnt, dentry, level); + dput(dentry); + } + inode_unlock(dir); +out: + ovl_cache_free(&list); +} + +void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt, + struct dentry *dentry, int level) +{ + int err; + + if (!d_is_dir(dentry) || level > 1) { + ovl_cleanup(dir, dentry); + return; + } + + err = ovl_do_rmdir(dir, dentry); + if (err) { + struct path path = { .mnt = mnt, .dentry = dentry }; + + inode_unlock(dir); + ovl_workdir_cleanup_recurse(&path, level + 1); + inode_lock_nested(dir, I_MUTEX_PARENT); + ovl_cleanup(dir, dentry); + } +} diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 4036132842b5..a4585f961bf9 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -814,6 +814,10 @@ retry: struct kstat stat = { .mode = S_IFDIR | 0, }; + struct iattr attr = { + .ia_valid = ATTR_MODE, + .ia_mode = stat.mode, + }; if (work->d_inode) { err = -EEXIST; @@ -821,7 +825,7 @@ retry: goto out_dput; retried = true; - ovl_cleanup(dir, work); + ovl_workdir_cleanup(dir, mnt, work, 0); dput(work); goto retry; } @@ -829,6 +833,21 @@ retry: err = ovl_create_real(dir, work, &stat, NULL, NULL, true); if (err) goto out_dput; + + err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_DEFAULT); + if (err && err != -ENODATA) + goto out_dput; + + err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_ACCESS); + if (err && err != -ENODATA) + goto out_dput; + + /* Clear any inherited mode bits */ + inode_lock(work->d_inode); + err = notify_change(work, &attr, NULL); + inode_unlock(work->d_inode); + if (err) + goto out_dput; } out_unlock: inode_unlock(dir); @@ -967,10 +986,19 @@ static unsigned int ovl_split_lowerdirs(char *str) return ctr; } -static int ovl_posix_acl_xattr_set(const struct xattr_handler *handler, - struct dentry *dentry, struct inode *inode, - const char *name, const void *value, - size_t size, int flags) +static int __maybe_unused +ovl_posix_acl_xattr_get(const struct xattr_handler *handler, + struct dentry *dentry, struct inode *inode, + const char *name, void *buffer, size_t size) +{ + return ovl_xattr_get(dentry, handler->name, buffer, size); +} + +static int __maybe_unused +ovl_posix_acl_xattr_set(const struct xattr_handler *handler, + struct dentry *dentry, struct inode *inode, + const char *name, const void *value, + size_t size, int flags) { struct dentry *workdir = ovl_workdir(dentry); struct inode *realinode = ovl_inode_real(inode, NULL); @@ -998,19 +1026,22 @@ static int ovl_posix_acl_xattr_set(const struct xattr_handler *handler, posix_acl_release(acl); - return ovl_setxattr(dentry, inode, handler->name, value, size, flags); + err = ovl_xattr_set(dentry, handler->name, value, size, flags); + if (!err) + ovl_copyattr(ovl_inode_real(inode, NULL), inode); + + return err; out_acl_release: posix_acl_release(acl); return err; } -static int ovl_other_xattr_set(const struct xattr_handler *handler, - struct dentry *dentry, struct inode *inode, - const char *name, const void *value, - size_t size, int flags) +static int ovl_own_xattr_get(const struct xattr_handler *handler, + struct dentry *dentry, struct inode *inode, + const char *name, void *buffer, size_t size) { - return ovl_setxattr(dentry, inode, name, value, size, flags); + return -EPERM; } static int ovl_own_xattr_set(const struct xattr_handler *handler, @@ -1021,42 +1052,59 @@ static int ovl_own_xattr_set(const struct xattr_handler *handler, return -EPERM; } -static const struct xattr_handler ovl_posix_acl_access_xattr_handler = { +static int ovl_other_xattr_get(const struct xattr_handler *handler, + struct dentry *dentry, struct inode *inode, + const char *name, void *buffer, size_t size) +{ + return ovl_xattr_get(dentry, name, buffer, size); +} + +static int ovl_other_xattr_set(const struct xattr_handler *handler, + struct dentry *dentry, struct inode *inode, + const char *name, const void *value, + size_t size, int flags) +{ + return ovl_xattr_set(dentry, name, value, size, flags); +} + +static const struct xattr_handler __maybe_unused +ovl_posix_acl_access_xattr_handler = { .name = XATTR_NAME_POSIX_ACL_ACCESS, .flags = ACL_TYPE_ACCESS, + .get = ovl_posix_acl_xattr_get, .set = ovl_posix_acl_xattr_set, }; -static const struct xattr_handler ovl_posix_acl_default_xattr_handler = { +static const struct xattr_handler __maybe_unused +ovl_posix_acl_default_xattr_handler = { .name = XATTR_NAME_POSIX_ACL_DEFAULT, .flags = ACL_TYPE_DEFAULT, + .get = ovl_posix_acl_xattr_get, .set = ovl_posix_acl_xattr_set, }; static const struct xattr_handler ovl_own_xattr_handler = { .prefix = OVL_XATTR_PREFIX, + .get = ovl_own_xattr_get, .set = ovl_own_xattr_set, }; static const struct xattr_handler ovl_other_xattr_handler = { .prefix = "", /* catch all */ + .get = ovl_other_xattr_get, .set = ovl_other_xattr_set, }; static const struct xattr_handler *ovl_xattr_handlers[] = { +#ifdef CONFIG_FS_POSIX_ACL &ovl_posix_acl_access_xattr_handler, &ovl_posix_acl_default_xattr_handler, +#endif &ovl_own_xattr_handler, &ovl_other_xattr_handler, NULL }; -static const struct xattr_handler *ovl_xattr_noacl_handlers[] = { - &ovl_own_xattr_handler, - &ovl_other_xattr_handler, - NULL, -}; - static int ovl_fill_super(struct super_block *sb, void *data, int silent) { struct path upperpath = { NULL, NULL }; @@ -1132,7 +1180,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) err = -EINVAL; stacklen = ovl_split_lowerdirs(lowertmp); if (stacklen > OVL_MAX_STACK) { - pr_err("overlayfs: too many lower directries, limit is %d\n", + pr_err("overlayfs: too many lower directories, limit is %d\n", OVL_MAX_STACK); goto out_free_lowertmp; } else if (!ufs->config.upperdir && stacklen == 1) { @@ -1269,10 +1317,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) sb->s_magic = OVERLAYFS_SUPER_MAGIC; sb->s_op = &ovl_super_operations; - if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) - sb->s_xattr = ovl_xattr_handlers; - else - sb->s_xattr = ovl_xattr_noacl_handlers; + sb->s_xattr = ovl_xattr_handlers; sb->s_root = root_dentry; sb->s_fs_info = ufs; sb->s_flags |= MS_POSIXACL; diff --git a/include/linux/fs.h b/include/linux/fs.h index 3523bf62f328..901e25d495cc 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -574,6 +574,7 @@ static inline void mapping_allow_writable(struct address_space *mapping) struct posix_acl; #define ACL_NOT_CACHED ((void *)(-1)) +#define ACL_DONT_CACHE ((void *)(-3)) static inline struct posix_acl * uncached_acl_sentinel(struct task_struct *task) |