[XFS] stop using uio in the readlink code

Simplify the readlink code to get rid of the last user of uio.

SGI-PV: 968563
SGI-Modid: xfs-linux-melb:xfs-kern:29479a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

1 files changed, 60 insertions, 72 deletions

diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 36318c66a7bf..bde4a1ad90f2 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -951,6 +951,53 @@ xfs_access(
  */
 #define SYMLINK_MAPS 2
 
+STATIC int
+xfs_readlink_bmap(
+        xfs_inode_t     *ip,
+        char            *link)
+{
+        xfs_mount_t     *mp = ip->i_mount;
+        int             pathlen = ip->i_d.di_size;
+        int             nmaps = SYMLINK_MAPS;
+        xfs_bmbt_irec_t mval[SYMLINK_MAPS];
+        xfs_daddr_t     d;
+        int             byte_cnt;
+        int             n;
+        xfs_buf_t       *bp;
+        int             error = 0;
+
+        error = xfs_bmapi(NULL, ip, 0, XFS_B_TO_FSB(mp, pathlen), 0, NULL, 0,
+                        mval, &nmaps, NULL, NULL);
+        if (error)
+                goto out;
+
+        for (n = 0; n < nmaps; n++) {
+                d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
+                byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
+
+                bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0);
+                error = XFS_BUF_GETERROR(bp);
+                if (error) {
+                        xfs_ioerror_alert("xfs_readlink",
+                                  ip->i_mount, bp, XFS_BUF_ADDR(bp));
+                        xfs_buf_relse(bp);
+                        goto out;
+                }
+                if (pathlen < byte_cnt)
+                        byte_cnt = pathlen;
+                pathlen -= byte_cnt;
+
+                memcpy(link, XFS_BUF_PTR(bp), byte_cnt);
+                xfs_buf_relse(bp);
+        }
+
+        link[ip->i_d.di_size] = '\0';
+        error = 0;
+
+ out:
+        return error;
+}
+
 /*
  * xfs_readlink
  *
@@ -958,29 +1005,14 @@ xfs_access(
 STATIC int
 xfs_readlink(
         bhv_desc_t      *bdp,
-        uio_t           *uiop,
-        int             ioflags,
-        cred_t          *credp)
+        char            *link)
 {
-        xfs_inode_t     *ip;
-        int             count;
-        xfs_off_t       offset;
+        xfs_inode_t     *ip = XFS_BHVTOI(bdp);
+        xfs_mount_t     *mp = ip->i_mount;
         int             pathlen;
-        bhv_vnode_t     *vp;
         int             error = 0;
-        xfs_mount_t     *mp;
-        int             nmaps;
-        xfs_bmbt_irec_t mval[SYMLINK_MAPS];
-        xfs_daddr_t     d;
-        int             byte_cnt;
-        int             n;
-        xfs_buf_t       *bp;
 
-        vp = BHV_TO_VNODE(bdp);
-        vn_trace_entry(vp, __FUNCTION__, (inst_t *)__return_address);
-
-        ip = XFS_BHVTOI(bdp);
-        mp = ip->i_mount;
+        vn_trace_entry(XFS_ITOV(ip), __FUNCTION__, (inst_t *)__return_address);
 
         if (XFS_FORCED_SHUTDOWN(mp))
                 return XFS_ERROR(EIO);
@@ -988,68 +1020,24 @@ xfs_readlink(
         xfs_ilock(ip, XFS_ILOCK_SHARED);
 
         ASSERT((ip->i_d.di_mode & S_IFMT) == S_IFLNK);
+        ASSERT(ip->i_d.di_size <= MAXPATHLEN);
 
-        offset = uiop->uio_offset;
-        count = uiop->uio_resid;
-
-        if (offset < 0) {
-                error = XFS_ERROR(EINVAL);
-                goto error_return;
-        }
-        if (count <= 0) {
-                error = 0;
-                goto error_return;
-        }
-
-        /*
-         * See if the symlink is stored inline.
-         */
-        pathlen = (int)ip->i_d.di_size;
+        pathlen = ip->i_d.di_size;
+        if (!pathlen)
+                goto out;
 
         if (ip->i_df.if_flags & XFS_IFINLINE) {
-                error = xfs_uio_read(ip->i_df.if_u1.if_data, pathlen, uiop);
-        }
-        else {
-                /*
-                 * Symlink not inline.  Call bmap to get it in.
-                 */
-                nmaps = SYMLINK_MAPS;
-
-                error = xfs_bmapi(NULL, ip, 0, XFS_B_TO_FSB(mp, pathlen),
-                                  0, NULL, 0, mval, &nmaps, NULL, NULL);
-
-                if (error) {
-                        goto error_return;
-                }
-
-                for (n = 0; n < nmaps; n++) {
-                        d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
-                        byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
-                        bp = xfs_buf_read(mp->m_ddev_targp, d,
-                                      BTOBB(byte_cnt), 0);
-                        error = XFS_BUF_GETERROR(bp);
-                        if (error) {
-                                xfs_ioerror_alert("xfs_readlink",
-                                          ip->i_mount, bp, XFS_BUF_ADDR(bp));
-                                xfs_buf_relse(bp);
-                                goto error_return;
-                        }
-                        if (pathlen < byte_cnt)
-                                byte_cnt = pathlen;
-                        pathlen -= byte_cnt;
-
-                        error = xfs_uio_read(XFS_BUF_PTR(bp), byte_cnt, uiop);
-                        xfs_buf_relse (bp);
-                }
-
+                memcpy(link, ip->i_df.if_u1.if_data, pathlen);
+                link[pathlen] = '\0';
+        } else {
+                error = xfs_readlink_bmap(ip, link);
         }
 
-error_return:
+ out:
         xfs_iunlock(ip, XFS_ILOCK_SHARED);
         return error;
 }
 
-
 /*
  * xfs_fsync
  *