LU-1540 osd: add NUL terminator for long symlink

Add NUL terminator for long symlink to ldiskfs inode on-disk data.

Signed-off-by: Bobi Jam <bobijam@whamcloud.com>
Change-Id: Id7ce7829ec9b4c8eb72cf257df046a5288a5eb7b
Reviewed-on: http://review.whamcloud.com/3765
Tested-by: Hudson
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>

diff --git a/lustre/osd-ldiskfs/osd_handler.c b/lustre/osd-ldiskfs/osd_handler.c
index 58e4771..dc443f4 100644 (file)
--- a/lustre/osd-ldiskfs/osd_handler.c
+++ b/lustre/osd-ldiskfs/osd_handler.c
@@ -2542,8 +2542,9 @@ static int osd_ldiskfs_writelink(struct inode *inode, char *buffer, int buflen)
         return 0;
 }
 
-static int osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
-                                    loff_t *offs, handle_t *handle)
+static int
+osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
+                         int write_NUL, loff_t *offs, handle_t *handle)
 {
         struct buffer_head *bh = NULL;
         loff_t offset = *offs;
@@ -2555,6 +2556,15 @@ static int osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
         int boffs;
         int dirty_inode = 0;
 
+        if (write_NUL) {
+                /*
+                 * long symlink write does not count the NUL terminator in
+                 * bufsize, we write it, and the inode's file size does not
+                 * count the NUL terminator as well.
+                 */
+                ((char*)buf)[bufsize] = '\0';
+                ++bufsize;
+        }
         while (bufsize > 0) {
                 if (bh != NULL)
                         brelse(bh);
@@ -2591,6 +2601,8 @@ static int osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
         if (bh)
                 brelse(bh);
 
+        if (write_NUL)
+                --new_size;
         /* correct in-core and on-disk sizes */
         if (new_size > i_size_read(inode)) {
                 spin_lock(&inode->i_lock);
@@ -2619,6 +2631,7 @@ static ssize_t osd_write(const struct lu_env *env, struct dt_object *dt,
         struct inode       *inode = obj->oo_inode;
         struct osd_thandle *oh;
         ssize_t            result = 0;
+        int                is_link;
 #ifdef HAVE_QUOTA_SUPPORT
         cfs_cap_t           save = cfs_curproc_cap_pack();
 #endif
@@ -2638,13 +2651,15 @@ static ssize_t osd_write(const struct lu_env *env, struct dt_object *dt,
 #endif
         /* Write small symlink to inode body as we need to maintain correct
          * on-disk symlinks for ldiskfs.
+         * Note: the buf->lb_buf contains a NUL terminator while buf->lb_len
+         * does not count it in.
          */
-        if(S_ISLNK(obj->oo_dt.do_lu.lo_header->loh_attr) &&
-           (buf->lb_len < sizeof (LDISKFS_I(inode)->i_data)))
+        is_link = S_ISLNK(dt->do_lu.lo_header->loh_attr);
+        if(is_link && (buf->lb_len < sizeof (LDISKFS_I(inode)->i_data)))
                 result = osd_ldiskfs_writelink(inode, buf->lb_buf, buf->lb_len);
         else
                 result = osd_ldiskfs_write_record(inode, buf->lb_buf,
-                                                  buf->lb_len, pos,
+                                                  buf->lb_len, is_link, pos,
                                                   oh->ot_handle);
 #ifdef HAVE_QUOTA_SUPPORT
         cfs_curproc_cap_unpack(save);

diff --git a/lustre/tests/sanity.sh b/lustre/tests/sanity.sh
index 7ce344b..e5897b5 100644 (file)
--- a/lustre/tests/sanity.sh
+++ b/lustre/tests/sanity.sh
@@ -496,6 +496,58 @@ test_17k() { #bug 22301
 }
 run_test 17k "symlinks: rsync with xattrs enabled ========================="
 
+# LU-1540
+test_17m() {
+        local short_sym="0123456789"
+        local WDIR=$DIR/${tdir}m
+        local mds_index
+        local devname
+        local cmd
+        local i
+        local rc=0
+
+        mkdir -p $WDIR
+        long_sym=$short_sym
+        # create a long symlink file
+        for ((i = 0; i < 4; ++i)); do
+                long_sym=${long_sym}${long_sym}
+        done
+
+        echo "create 512 short and long symlink files under $WDIR"
+        for ((i = 0; i < 256; ++i)); do
+                ln -sf ${long_sym}"a5a5" $WDIR/long-$i
+                ln -sf ${short_sym}"a5a5" $WDIR/short-$i
+        done
+
+        echo "erase them"
+        rm -f $WDIR/*
+        sync
+        sleep 2
+
+        echo "recreate the 512 symlink files with a shorter string"
+        for ((i = 0; i < 512; ++i)); do
+                # rewrite the symlink file with a shorter string
+                ln -sf ${long_sym} $WDIR/long-$i
+                ln -sf ${short_sym} $WDIR/short-$i
+        done
+
+        mds_index=1
+        devname=$(mdsdevname $mds_index)
+        cmd="$E2FSCK -fnvd $devname"
+
+        echo "stop and checking mds${mds_index}: $cmd"
+        # e2fsck should not return error
+        stop mds${mds_index} -f
+        do_facet mds${mds_index} $cmd || rc=$?
+
+        start mds${mds_index} $devname $MDS_MOUNT_OPTS
+        df $MOUNT > /dev/null 2>&1
+        [ $rc -ne 0 ] && error "e2fsck should not report error upon "\
+                "short/long symlink MDT: rc=$rc"
+        return $rc
+}
+run_test 17m "run e2fsck against MDT which contains short/long symlink"
+
 test_18() {
        touch $DIR/f
        ls $DIR || error