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Diffstat (limited to 'fs/cifs/link.c')
-rw-r--r--fs/cifs/link.c79
1 files changed, 79 insertions, 0 deletions
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 12eb491d4c52..bec212b09a02 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -91,6 +91,85 @@ CIFSParseMFSymlink(const u8 *buf,
return 0;
}
+bool
+CIFSCouldBeMFSymlink(const struct cifs_fattr *fattr)
+{
+ if (!(fattr->cf_mode & S_IFREG))
+ /* it's not a symlink */
+ return false;
+
+ if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
+ /* it's not a symlink */
+ return false;
+
+ return true;
+}
+
+int
+CIFSCheckMFSymlink(struct cifs_fattr *fattr,
+ const unsigned char *path,
+ struct cifs_sb_info *cifs_sb, int xid)
+{
+ int rc;
+ int oplock = 0;
+ __u16 netfid = 0;
+ struct cifsTconInfo *pTcon = cifs_sb->tcon;
+ u8 *buf;
+ char *pbuf;
+ unsigned int bytes_read = 0;
+ int buf_type = CIFS_NO_BUFFER;
+ unsigned int link_len = 0;
+ FILE_ALL_INFO file_info;
+
+ if (!CIFSCouldBeMFSymlink(fattr))
+ /* it's not a symlink */
+ return 0;
+
+ rc = CIFSSMBOpen(xid, pTcon, path, FILE_OPEN, GENERIC_READ,
+ CREATE_NOT_DIR, &netfid, &oplock, &file_info,
+ cifs_sb->local_nls,
+ cifs_sb->mnt_cifs_flags &
+ CIFS_MOUNT_MAP_SPECIAL_CHR);
+ if (rc != 0)
+ return rc;
+
+ if (file_info.EndOfFile != CIFS_MF_SYMLINK_FILE_SIZE) {
+ CIFSSMBClose(xid, pTcon, netfid);
+ /* it's not a symlink */
+ return 0;
+ }
+
+ buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+ pbuf = buf;
+
+ rc = CIFSSMBRead(xid, pTcon, netfid,
+ CIFS_MF_SYMLINK_FILE_SIZE /* length */,
+ 0 /* offset */,
+ &bytes_read, &pbuf, &buf_type);
+ CIFSSMBClose(xid, pTcon, netfid);
+ if (rc != 0) {
+ kfree(buf);
+ return rc;
+ }
+
+ rc = CIFSParseMFSymlink(buf, bytes_read, &link_len, NULL);
+ kfree(buf);
+ if (rc == -EINVAL)
+ /* it's not a symlink */
+ return 0;
+ if (rc != 0)
+ return rc;
+
+ /* it is a symlink */
+ fattr->cf_eof = link_len;
+ fattr->cf_mode &= ~S_IFMT;
+ fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
+ fattr->cf_dtype = DT_LNK;
+ return 0;
+}
+
int
cifs_hardlink(struct dentry *old_file, struct inode *inode,
struct dentry *direntry)