From 3d3ea8e64efbeb3e4289675dbbfab82333395642 Mon Sep 17 00:00:00 2001 From: Shirish Pargaonkar Date: Mon, 26 Sep 2011 09:56:44 -0500 Subject: cifs: Add mount options for backup intent (try #6) Add mount options backupuid and backugid. It allows an authenticated user to access files with the intent to back them up including their ACLs, who may not have access permission but has "Backup files and directories user right" on them (by virtue of being part of the built-in group Backup Operators. When mount options backupuid is specified, cifs client restricts the use of backup intents to the user whose effective user id is specified along with the mount option. When mount options backupgid is specified, cifs client restricts the use of backup intents to the users whose effective user id belongs to the group id specified along with the mount option. If an authenticated user is not part of the built-in group Backup Operators at the server, access to such files is denied, even if allowed by the client. Signed-off-by: Shirish Pargaonkar Reviewed-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/link.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) (limited to 'fs/cifs/link.c') diff --git a/fs/cifs/link.c b/fs/cifs/link.c index db3f18cdf024..8693b5d0e180 100644 --- a/fs/cifs/link.c +++ b/fs/cifs/link.c @@ -183,14 +183,20 @@ CIFSFormatMFSymlink(u8 *buf, unsigned int buf_len, const char *link_str) static int CIFSCreateMFSymLink(const int xid, struct cifs_tcon *tcon, const char *fromName, const char *toName, - const struct nls_table *nls_codepage, int remap) + struct cifs_sb_info *cifs_sb) { int rc; int oplock = 0; + int remap; + int create_options = CREATE_NOT_DIR; __u16 netfid = 0; u8 *buf; unsigned int bytes_written = 0; struct cifs_io_parms io_parms; + struct nls_table *nls_codepage; + + nls_codepage = cifs_sb->local_nls; + remap = cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR; buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL); if (!buf) @@ -202,8 +208,11 @@ CIFSCreateMFSymLink(const int xid, struct cifs_tcon *tcon, return rc; } + if (backup_cred(cifs_sb)) + create_options |= CREATE_OPEN_BACKUP_INTENT; + rc = CIFSSMBOpen(xid, tcon, fromName, FILE_CREATE, GENERIC_WRITE, - CREATE_NOT_DIR, &netfid, &oplock, NULL, + create_options, &netfid, &oplock, NULL, nls_codepage, remap); if (rc != 0) { kfree(buf); @@ -559,9 +568,7 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname) /* BB what if DFS and this volume is on different share? BB */ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) rc = CIFSCreateMFSymLink(xid, pTcon, full_path, symname, - cifs_sb->local_nls, - cifs_sb->mnt_cifs_flags & - CIFS_MOUNT_MAP_SPECIAL_CHR); + cifs_sb); else if (pTcon->unix_ext) rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname, cifs_sb->local_nls); -- cgit v1.2.3-58-ga151