// SPDX-License-Identifier: LGPL-2.1 /* * * vfs operations that deal with dentries * * Copyright (C) International Business Machines Corp., 2002,2009 * Author(s): Steve French (sfrench@us.ibm.com) * */ #include <linux/fs.h> #include <linux/stat.h> #include <linux/slab.h> #include <linux/namei.h> #include <linux/mount.h> #include <linux/file.h> #include "cifsfs.h" #include "cifspdu.h" #include "cifsglob.h" #include "cifsproto.h" #include "cifs_debug.h" #include "cifs_fs_sb.h" #include "cifs_unicode.h" #include "fs_context.h" #include "cifs_ioctl.h" static void renew_parental_timestamps(struct dentry *direntry) { /* BB check if there is a way to get the kernel to do this or if we really need this */ do { cifs_set_time(direntry, jiffies); direntry = direntry->d_parent; } while (!IS_ROOT(direntry)); } char * cifs_build_path_to_root(struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb, struct cifs_tcon *tcon, int add_treename) { int pplen = ctx->prepath ? strlen(ctx->prepath) + 1 : 0; int dfsplen; char *full_path = NULL; /* if no prefix path, simply set path to the root of share to "" */ if (pplen == 0) { full_path = kzalloc(1, GFP_KERNEL); return full_path; } if (add_treename) dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1); else dfsplen = 0; full_path = kmalloc(dfsplen + pplen + 1, GFP_KERNEL); if (full_path == NULL) return full_path; if (dfsplen) memcpy(full_path, tcon->treeName, dfsplen); full_path[dfsplen] = CIFS_DIR_SEP(cifs_sb); memcpy(full_path + dfsplen + 1, ctx->prepath, pplen); convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb)); return full_path; } /* Note: caller must free return buffer */ const char * build_path_from_dentry(struct dentry *direntry, void *page) { struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb); struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb); bool prefix = tcon->Flags & SMB_SHARE_IS_IN_DFS; return build_path_from_dentry_optional_prefix(direntry, page, prefix); } char * build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page, bool prefix) { int dfsplen; int pplen = 0; struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb); struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb); char dirsep = CIFS_DIR_SEP(cifs_sb); char *s; if (unlikely(!page)) return ERR_PTR(-ENOMEM); if (prefix) dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1); else dfsplen = 0; if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) pplen = cifs_sb->prepath ? strlen(cifs_sb->prepath) + 1 : 0; s = dentry_path_raw(direntry, page, PATH_MAX); if (IS_ERR(s)) return s; if (!s[1]) // for root we want "", not "/" s++; if (s < (char *)page + pplen + dfsplen) return ERR_PTR(-ENAMETOOLONG); if (pplen) { cifs_dbg(FYI, "using cifs_sb prepath <%s>\n", cifs_sb->prepath); s -= pplen; memcpy(s + 1, cifs_sb->prepath, pplen - 1); *s = '/'; } if (dirsep != '/') { /* BB test paths to Windows with '/' in the midst of prepath */ char *p; for (p = s; *p; p++) if (*p == '/') *p = dirsep; } if (dfsplen) { s -= dfsplen; memcpy(s, tcon->treeName, dfsplen); if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) { int i; for (i = 0; i < dfsplen; i++) { if (s[i] == '\\') s[i] = '/'; } } } return s; } /* * Don't allow path components longer than the server max. * Don't allow the separator character in a path component. * The VFS will not allow "/", but "\" is allowed by posix. */ static int check_name(struct dentry *direntry, struct cifs_tcon *tcon) { struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb); int i; if (unlikely(tcon->fsAttrInfo.MaxPathNameComponentLength && direntry->d_name.len > le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength))) return -ENAMETOOLONG; if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) { for (i = 0; i < direntry->d_name.len; i++) { if (direntry->d_name.name[i] == '\\') { cifs_dbg(FYI, "Invalid file name\n"); return -EINVAL; } } } return 0; } /* Inode operations in similar order to how they appear in Linux file fs.h */ static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid, struct tcon_link *tlink, unsigned oflags, umode_t mode, __u32 *oplock, struct cifs_fid *fid) { int rc = -ENOENT; int create_options = CREATE_NOT_DIR; int desired_access; struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); struct cifs_tcon *tcon = tlink_tcon(tlink); const char *full_path; void *page = alloc_dentry_path(); FILE_ALL_INFO *buf = NULL; struct inode *newinode = NULL; int disposition; struct TCP_Server_Info *server = tcon->ses->server; struct cifs_open_parms oparms; *oplock = 0; if (tcon->ses->server->oplocks) *oplock = REQ_OPLOCK; full_path = build_path_from_dentry(direntry, page); if (IS_ERR(full_path)) { free_dentry_path(page); return PTR_ERR(full_path); } if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open && (CIFS_UNIX_POSIX_PATH_OPS_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))) { rc = cifs_posix_open(full_path, &newinode, inode->i_sb, mode, oflags, oplock, &fid->netfid, xid); switch (rc) { case 0: if (newinode == NULL) { /* query inode info */ goto cifs_create_get_file_info; } if (S_ISDIR(newinode->i_mode)) { CIFSSMBClose(xid, tcon, fid->netfid); iput(newinode); rc = -EISDIR; goto out; } if (!S_ISREG(newinode->i_mode)) { /* * The server may allow us to open things like * FIFOs, but the client isn't set up to deal * with that. If it's not a regular file, just * close it and proceed as if it were a normal * lookup. */ CIFSSMBClose(xid, tcon, fid->netfid); goto cifs_create_get_file_info; } /* success, no need to query */ goto cifs_create_set_dentry; case -ENOENT: goto cifs_create_get_file_info; case -EIO: case -EINVAL: /* * EIO could indicate that (posix open) operation is not * supported, despite what server claimed in capability * negotiation. * * POSIX open in samba versions 3.3.1 and earlier could * incorrectly fail with invalid parameter. */ tcon->broken_posix_open = true; break; case -EREMOTE: case -EOPNOTSUPP: /* * EREMOTE indicates DFS junction, which is not handled * in posix open. If either that or op not supported * returned, follow the normal lookup. */ break; default: goto out; } /* * fallthrough to retry, using older open call, this is case * where server does not support this SMB level, and falsely * claims capability (also get here for DFS case which should be * rare for path not covered on files) */ } desired_access = 0; if (OPEN_FMODE(oflags) & FMODE_READ) desired_access |= GENERIC_READ; /* is this too little? */ if (OPEN_FMODE(oflags) & FMODE_WRITE) desired_access |= GENERIC_WRITE; disposition = FILE_OVERWRITE_IF; if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) disposition = FILE_CREATE; else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC)) disposition = FILE_OVERWRITE_IF; else if ((oflags & O_CREAT) == O_CREAT) disposition = FILE_OPEN_IF; else cifs_dbg(FYI, "Create flag not set in create function\n"); /* * BB add processing to set equivalent of mode - e.g. via CreateX with * ACLs */ if (!server->ops->open) { rc = -ENOSYS; goto out; } buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL); if (buf == NULL) { rc = -ENOMEM; goto out; } /* * if we're not using unix extensions, see if we need to set * ATTR_READONLY on the create call */ if (!tcon->unix_ext && (mode & S_IWUGO) == 0) create_options |= CREATE_OPTION_READONLY; oparms.tcon = tcon; oparms.cifs_sb = cifs_sb; oparms.desired_access = desired_access; oparms.create_options = cifs_create_options(cifs_sb, create_options); oparms.disposition = disposition; oparms.path = full_path; oparms.fid = fid; oparms.reconnect = false; oparms.mode = mode; rc = server->ops->open(xid, &oparms, oplock, buf); if (rc) { cifs_dbg(FYI, "cifs_create returned 0x%x\n", rc); goto out; } /* * If Open reported that we actually created a file then we now have to * set the mode if possible. */ if ((tcon->unix_ext) && (*oplock & CIFS_CREATE_ACTION)) { struct cifs_unix_set_info_args args = { .mode = mode, .ctime = NO_CHANGE_64, .atime = NO_CHANGE_64, .mtime = NO_CHANGE_64, .device = 0, }; if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) { args.uid = current_fsuid(); if (inode->i_mode & S_ISGID) args.gid = inode->i_gid; else args.gid = current_fsgid(); } else { args.uid = INVALID_UID; /* no change */ args.gid = INVALID_GID; /* no change */ } CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid->netfid, current->tgid); } else { /* * BB implement mode setting via Windows security * descriptors e.g. */ /* CIFSSMBWinSetPerms(xid,tcon,path,mode,-1,-1,nls);*/ /* Could set r/o dos attribute if mode & 0222 == 0 */ } cifs_create_get_file_info: /* server might mask mode so we have to query for it */ if (tcon->unix_ext) rc = cifs_get_inode_info_unix(&newinode, full_path, inode->i_sb, xid); else { /* TODO: Add support for calling POSIX query info here, but passing in fid */ rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb, xid, fid); if (newinode) { if (server->ops->set_lease_key) server->ops->set_lease_key(newinode, fid); if ((*oplock & CIFS_CREATE_ACTION) && S_ISREG(newinode->i_mode)) { if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM) newinode->i_mode = mode; if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) { newinode->i_uid = current_fsuid(); if (inode->i_mode & S_ISGID) newinode->i_gid = inode->i_gid; else newinode->i_gid = current_fsgid(); } } } } cifs_create_set_dentry: if (rc != 0) { cifs_dbg(FYI, "Create worked, get_inode_info failed rc = %d\n", rc); goto out_err; } if (newinode) if (S_ISDIR(newinode->i_mode)) { rc = -EISDIR; goto out_err; } d_drop(direntry); d_add(direntry, newinode); out: kfree(buf); free_dentry_path(page); return rc; out_err: if (server->ops->close) server->ops->close(xid, tcon, fid); if (newinode) iput(newinode); goto out; } int cifs_atomic_open(struct inode *inode, struct dentry *direntry, struct file *file, unsigned oflags, umode_t mode) { int rc; unsigned int xid; struct tcon_link *tlink; struct cifs_tcon *tcon; struct TCP_Server_Info *server; struct cifs_fid fid; struct cifs_pending_open open; __u32 oplock; struct cifsFileInfo *file_info; if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb)))) return -EIO; /* * Posix open is only called (at lookup time) for file create now. For * opens (rather than creates), because we do not know if it is a file * or directory yet, and current Samba no longer allows us to do posix * open on dirs, we could end up wasting an open call on what turns out * to be a dir. For file opens, we wait to call posix open till * cifs_open. It could be added to atomic_open in the future but the * performance tradeoff of the extra network request when EISDIR or * EACCES is returned would have to be weighed against the 50% reduction * in network traffic in the other paths. */ if (!(oflags & O_CREAT)) { struct dentry *res; /* * Check for hashed negative dentry. We have already revalidated * the dentry and it is fine. No need to perform another lookup. */ if (!d_in_lookup(direntry)) return -ENOENT; res = cifs_lookup(inode, direntry, 0); if (IS_ERR(res)) return PTR_ERR(res); return finish_no_open(file, res); } xid = get_xid(); cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n", inode, direntry, direntry); tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb)); if (IS_ERR(tlink)) { rc = PTR_ERR(tlink); goto out_free_xid; } tcon = tlink_tcon(tlink); rc = check_name(direntry, tcon); if (rc) goto out; server = tcon->ses->server; if (server->ops->new_lease_key) server->ops->new_lease_key(&fid); cifs_add_pending_open(&fid, tlink, &open); rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode, &oplock, &fid); if (rc) { cifs_del_pending_open(&open); goto out; } if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) file->f_mode |= FMODE_CREATED; rc = finish_open(file, direntry, generic_file_open); if (rc) { if (server->ops->close) server->ops->close(xid, tcon, &fid); cifs_del_pending_open(&open); goto out; } if (file->f_flags & O_DIRECT && CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) { if (CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NO_BRL) file->f_op = &cifs_file_direct_nobrl_ops; else file->f_op = &cifs_file_direct_ops; } file_info = cifs_new_fileinfo(&fid, file, tlink, oplock); if (file_info == NULL) { if (server->ops->close) server->ops->close(xid, tcon, &fid); cifs_del_pending_open(&open); rc = -ENOMEM; } out: cifs_put_tlink(tlink); out_free_xid: free_xid(xid); return rc; } int cifs_create(struct user_namespace *mnt_userns, struct inode *inode, struct dentry *direntry, umode_t mode, bool excl) { int rc; unsigned int xid = get_xid(); /* * BB below access is probably too much for mknod to request * but we have to do query and setpathinfo so requesting * less could fail (unless we want to request getatr and setatr * permissions (only). At least for POSIX we do not have to * request so much. */ unsigned oflags = O_EXCL | O_CREAT | O_RDWR; struct tcon_link *tlink; struct cifs_tcon *tcon; struct TCP_Server_Info *server; struct cifs_fid fid; __u32 oplock; cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n", inode, direntry, direntry); if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb)))) return -EIO; tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb)); rc = PTR_ERR(tlink); if (IS_ERR(tlink)) goto out_free_xid; tcon = tlink_tcon(tlink); server = tcon->ses->server; if (server->ops->new_lease_key) server->ops->new_lease_key(&fid); rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode, &oplock, &fid); if (!rc && server->ops->close) server->ops->close(xid, tcon, &fid); cifs_put_tlink(tlink); out_free_xid: free_xid(xid); return rc; } int cifs_mknod(struct user_namespace *mnt_userns, struct inode *inode, struct dentry *direntry, umode_t mode, dev_t device_number) { int rc = -EPERM; unsigned int xid; struct cifs_sb_info *cifs_sb; struct tcon_link *tlink; struct cifs_tcon *tcon; const char *full_path; void *page; if (!old_valid_dev(device_number)) return -EINVAL; cifs_sb = CIFS_SB(inode->i_sb); if (unlikely(cifs_forced_shutdown(cifs_sb))) return -EIO; tlink = cifs_sb_tlink(cifs_sb); if (IS_ERR(tlink)) return PTR_ERR(tlink); page = alloc_dentry_path(); tcon = tlink_tcon(tlink); xid = get_xid(); full_path = build_path_from_dentry(direntry, page); if (IS_ERR(full_path)) { rc = PTR_ERR(full_path); goto mknod_out; } rc = tcon->ses->server->ops->make_node(xid, inode, direntry, tcon, full_path, mode, device_number); mknod_out: free_dentry_path(page); free_xid(xid); cifs_put_tlink(tlink); return rc; } struct dentry * cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, unsigned int flags) { unsigned int xid; int rc = 0; /* to get around spurious gcc warning, set to zero here */ struct cifs_sb_info *cifs_sb; struct tcon_link *tlink; struct cifs_tcon *pTcon; struct inode *newInode = NULL; const char *full_path; void *page; int retry_count = 0; xid = get_xid(); cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n", parent_dir_inode, direntry, direntry); /* check whether path exists */ cifs_sb = CIFS_SB(parent_dir_inode->i_sb); tlink = cifs_sb_tlink(cifs_sb); if (IS_ERR(tlink)) { free_xid(xid); return ERR_CAST(tlink); } pTcon = tlink_tcon(tlink); rc = check_name(direntry, pTcon); if (unlikely(rc)) { cifs_put_tlink(tlink); free_xid(xid); return ERR_PTR(rc); } /* can not grab the rename sem here since it would deadlock in the cases (beginning of sys_rename itself) in which we already have the sb rename sem */ page = alloc_dentry_path(); full_path = build_path_from_dentry(direntry, page); if (IS_ERR(full_path)) { cifs_put_tlink(tlink); free_xid(xid); free_dentry_path(page); return ERR_CAST(full_path); } if (d_really_is_positive(direntry)) { cifs_dbg(FYI, "non-NULL inode in lookup\n"); } else { cifs_dbg(FYI, "NULL inode in lookup\n"); } cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, d_inode(direntry)); again: if (pTcon->posix_extensions) rc = smb311_posix_get_inode_info(&newInode, full_path, parent_dir_inode->i_sb, xid); else if (pTcon->unix_ext) { rc = cifs_get_inode_info_unix(&newInode, full_path, parent_dir_inode->i_sb, xid); } else { rc = cifs_get_inode_info(&newInode, full_path, NULL, parent_dir_inode->i_sb, xid, NULL); } if (rc == 0) { /* since paths are not looked up by component - the parent directories are presumed to be good here */ renew_parental_timestamps(direntry); } else if (rc == -EAGAIN && retry_count++ < 10) { goto again; } else if (rc == -ENOENT) { cifs_set_time(direntry, jiffies); newInode = NULL; } else { if (rc != -EACCES) { cifs_dbg(FYI, "Unexpected lookup error %d\n", rc); /* We special case check for Access Denied - since that is a common return code */ } newInode = ERR_PTR(rc); } free_dentry_path(page); cifs_put_tlink(tlink); free_xid(xid); return d_splice_alias(newInode, direntry); } static int cifs_d_revalidate(struct dentry *direntry, unsigned int flags) { struct inode *inode; int rc; if (flags & LOOKUP_RCU) return -ECHILD; if (d_really_is_positive(direntry)) { inode = d_inode(direntry); if ((flags & LOOKUP_REVAL) && !CIFS_CACHE_READ(CIFS_I(inode))) CIFS_I(inode)->time = 0; /* force reval */ rc = cifs_revalidate_dentry(direntry); if (rc) { cifs_dbg(FYI, "cifs_revalidate_dentry failed with rc=%d", rc); switch (rc) { case -ENOENT: case -ESTALE: /* * Those errors mean the dentry is invalid * (file was deleted or recreated) */ return 0; default: /* * Otherwise some unexpected error happened * report it as-is to VFS layer */ return rc; } } else { /* * If the inode wasn't known to be a dfs entry when * the dentry was instantiated, such as when created * via ->readdir(), it needs to be set now since the * attributes will have been updated by * cifs_revalidate_dentry(). */ if (IS_AUTOMOUNT(inode) && !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) { spin_lock(&direntry->d_lock); direntry->d_flags |= DCACHE_NEED_AUTOMOUNT; spin_unlock(&direntry->d_lock); } return 1; } } /* * This may be nfsd (or something), anyway, we can't see the * intent of this. So, since this can be for creation, drop it. */ if (!flags) return 0; /* * Drop the negative dentry, in order to make sure to use the * case sensitive name which is specified by user if this is * for creation. */ if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET)) return 0; if (time_after(jiffies, cifs_get_time(direntry) + HZ) || !lookupCacheEnabled) return 0; return 1; } /* static int cifs_d_delete(struct dentry *direntry) { int rc = 0; cifs_dbg(FYI, "In cifs d_delete, name = %pd\n", direntry); return rc; } */ const struct dentry_operations cifs_dentry_ops = { .d_revalidate = cifs_d_revalidate, .d_automount = cifs_dfs_d_automount, /* d_delete: cifs_d_delete, */ /* not needed except for debugging */ }; static int cifs_ci_hash(const struct dentry *dentry, struct qstr *q) { struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls; unsigned long hash; wchar_t c; int i, charlen; hash = init_name_hash(dentry); for (i = 0; i < q->len; i += charlen) { charlen = codepage->char2uni(&q->name[i], q->len - i, &c); /* error out if we can't convert the character */ if (unlikely(charlen < 0)) return charlen; hash = partial_name_hash(cifs_toupper(c), hash); } q->hash = end_name_hash(hash); return 0; } static int cifs_ci_compare(const struct dentry *dentry, unsigned int len, const char *str, const struct qstr *name) { struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls; wchar_t c1, c2; int i, l1, l2; /* * We make the assumption here that uppercase characters in the local * codepage are always the same length as their lowercase counterparts. * * If that's ever not the case, then this will fail to match it. */ if (name->len != len) return 1; for (i = 0; i < len; i += l1) { /* Convert characters in both strings to UTF-16. */ l1 = codepage->char2uni(&str[i], len - i, &c1); l2 = codepage->char2uni(&name->name[i], name->len - i, &c2); /* * If we can't convert either character, just declare it to * be 1 byte long and compare the original byte. */ if (unlikely(l1 < 0 && l2 < 0)) { if (str[i] != name->name[i]) return 1; l1 = 1; continue; } /* * Here, we again ass|u|me that upper/lowercase versions of * a character are the same length in the local NLS. */ if (l1 != l2) return 1; /* Now compare uppercase versions of these characters */ if (cifs_toupper(c1) != cifs_toupper(c2)) return 1; } return 0; } const struct dentry_operations cifs_ci_dentry_ops = { .d_revalidate = cifs_d_revalidate, .d_hash = cifs_ci_hash, .d_compare = cifs_ci_compare, .d_automount = cifs_dfs_d_automount, };