From 924e3fa48c627ad45d3be9412a93df34ab0fb482 Mon Sep 17 00:00:00 2001 From: Sachin Prabhu Date: Mon, 2 Dec 2013 16:37:43 +0000 Subject: cifs: Add support for follow_link on dfs shares under posix extensions When using posix extensions, dfs shares in the dfs root show up as symlinks resulting in userland tools such as 'ls' calling readlink() on these shares. Since these are dfs shares, we end up returning -EREMOTE. $ ls -l /mnt ls: cannot read symbolic link /mnt/test: Object is remote total 0 lrwxrwxrwx. 1 root root 19 Nov 6 09:47 test With added follow_link() support for dfs shares, when using unix extensions, we call GET_DFS_REFERRAL to obtain the DFS referral and return the first node returned. The dfs share in the dfs root is now displayed in the following manner. $ ls -l /mnt total 0 lrwxrwxrwx. 1 root root 19 Nov 6 09:47 test -> \vm140-31\test Signed-off-by: Sachin Prabhu Reviewed-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/smb1ops.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'fs/cifs') diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c index 988fddb72025..abd2cc9515c9 100644 --- a/fs/cifs/smb1ops.c +++ b/fs/cifs/smb1ops.c @@ -907,6 +907,33 @@ cifs_mand_lock(const unsigned int xid, struct cifsFileInfo *cfile, __u64 offset, (__u8)type, wait, 0); } +static int +cifs_unix_dfs_readlink(const unsigned int xid, struct cifs_tcon *tcon, + const unsigned char *searchName, char **symlinkinfo, + const struct nls_table *nls_codepage) +{ +#ifdef CONFIG_CIFS_DFS_UPCALL + int rc; + unsigned int num_referrals = 0; + struct dfs_info3_param *referrals = NULL; + + rc = get_dfs_path(xid, tcon->ses, searchName, nls_codepage, + &num_referrals, &referrals, 0); + + if (!rc && num_referrals > 0) { + *symlinkinfo = kstrndup(referrals->node_name, + strlen(referrals->node_name), + GFP_KERNEL); + if (!*symlinkinfo) + rc = -ENOMEM; + free_dfs_info_array(referrals, num_referrals); + } + return rc; +#else /* No DFS support */ + return -EREMOTE; +#endif +} + static int cifs_query_symlink(const unsigned int xid, struct cifs_tcon *tcon, const char *full_path, char **target_path, @@ -922,6 +949,11 @@ cifs_query_symlink(const unsigned int xid, struct cifs_tcon *tcon, if (cap_unix(tcon->ses)) { rc = CIFSSMBUnixQuerySymLink(xid, tcon, full_path, target_path, cifs_sb->local_nls); + if (rc == -EREMOTE) + rc = cifs_unix_dfs_readlink(xid, tcon, full_path, + target_path, + cifs_sb->local_nls); + goto out; } -- cgit v1.2.3