Commit 750b8de6 authored by Sachin Prabhu's avatar Sachin Prabhu Committed by Steve French
Browse files

cifs: We do not drop reference to tlink in CIFSCheckMFSymlink() 



When we obtain tcon from cifs_sb, we use cifs_sb_tlink() to first obtain
tlink which also grabs a reference to it. We do not drop this reference
to tlink once we are done with the call.

The patch fixes this issue by instead passing tcon as a parameter and
avoids having to obtain a reference to the tlink. A lookup for the tcon
is already made in the calling functions and this way we avoid having to
re-run the lookup. This is also consistent with the argument list for
other similar calls for M-F symlinks.

We should also return an ENOSYS when we do not find a protocol specific
function to lookup the MF Symlink data.

Signed-off-by: default avatarSachin Prabhu <sprabhu@redhat.com>
Reviewed-by: default avatarJeff Layton <jlayton@redhat.com>
CC: Stable <stable@kernel.org>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
parent ebcc943c

fs/cifs/cifsproto.h

+4 −3
Original line number Diff line number Diff line
@@ -477,9 +477,10 @@ extern int CIFSGetExtAttr(const unsigned int xid, struct cifs_tcon *tcon, 
			const int netfid, __u64 *pExtAttrBits, __u64 *pMask);

extern void cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb);

extern bool CIFSCouldBeMFSymlink(const struct cifs_fattr *fattr);

extern int CIFSCheckMFSymlink(struct cifs_fattr *fattr,

		const unsigned char *path,

		struct cifs_sb_info *cifs_sb, unsigned int xid);

extern int CIFSCheckMFSymlink(unsigned int xid, struct cifs_tcon *tcon,

			      struct cifs_sb_info *cifs_sb,

			      struct cifs_fattr *fattr,

			      const unsigned char *path);

extern int mdfour(unsigned char *, unsigned char *, int);

extern int E_md4hash(const unsigned char *passwd, unsigned char *p16,

			const struct nls_table *codepage);

fs/cifs/inode.c

+4 −2
Original line number Diff line number Diff line
@@ -383,7 +383,8 @@ int cifs_get_inode_info_unix(struct inode **pinode, 


	/* check for Minshall+French symlinks */

	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) {

		int tmprc = CIFSCheckMFSymlink(&fattr, full_path, cifs_sb, xid);

		int tmprc = CIFSCheckMFSymlink(xid, tcon, cifs_sb, &fattr,

					       full_path);

		if (tmprc)

			cifs_dbg(FYI, "CIFSCheckMFSymlink: %d\n", tmprc);

	}
@@ -799,7 +800,8 @@ cifs_get_inode_info(struct inode **inode, const char *full_path, 


	/* check for Minshall+French symlinks */

	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) {

		tmprc = CIFSCheckMFSymlink(&fattr, full_path, cifs_sb, xid);

		tmprc = CIFSCheckMFSymlink(xid, tcon, cifs_sb, &fattr,

					   full_path);

		if (tmprc)

			cifs_dbg(FYI, "CIFSCheckMFSymlink: %d\n", tmprc);

	}

fs/cifs/link.c

+11 −15
Original line number Diff line number Diff line
@@ -354,34 +354,30 @@ open_query_close_cifs_symlink(const unsigned char *path, char *pbuf, 




int

CIFSCheckMFSymlink(struct cifs_fattr *fattr,

		   const unsigned char *path,

		   struct cifs_sb_info *cifs_sb, unsigned int xid)

CIFSCheckMFSymlink(unsigned int xid, struct cifs_tcon *tcon,

		   struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,

		   const unsigned char *path)

{

	int rc = 0;

	int rc;

	u8 *buf = NULL;

	unsigned int link_len = 0;

	unsigned int bytes_read = 0;

	struct cifs_tcon *ptcon;



	if (!CIFSCouldBeMFSymlink(fattr))

		/* it's not a symlink */

		return 0;



	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);

	if (!buf) {

		rc = -ENOMEM;

		goto out;

	}

	if (!buf)

		return -ENOMEM;



	ptcon = tlink_tcon(cifs_sb_tlink(cifs_sb));

	if ((ptcon->ses) && (ptcon->ses->server->ops->query_mf_symlink))

		rc = ptcon->ses->server->ops->query_mf_symlink(path, buf,

	if (tcon->ses->server->ops->query_mf_symlink)

		rc = tcon->ses->server->ops->query_mf_symlink(path, buf,

						&bytes_read, cifs_sb, xid);

	else

		goto out;

		rc = -ENOSYS;



	if (rc != 0)

	if (rc)

		goto out;



	if (bytes_read == 0) /* not a symlink */

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