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/3560
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/osd-ldiskfs/osd_internal.h b/lustre/osd-ldiskfs/osd_internal.h
index 6617c25..879343c 100644 (file)
--- a/lustre/osd-ldiskfs/osd_internal.h
+++ b/lustre/osd-ldiskfs/osd_internal.h
@@ -809,7 +809,7 @@ static inline void osd_ipd_put(const struct lu_env *env,
 
 int osd_ldiskfs_read(struct inode *inode, void *buf, int size, loff_t *offs);
 int osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
-                            loff_t *offs, handle_t *handle);
+                            int write_NUL, loff_t *offs, handle_t *handle);
 
 static inline
 struct dentry *osd_child_dentry_by_inode(const struct lu_env *env,

diff --git a/lustre/osd-ldiskfs/osd_io.c b/lustre/osd-ldiskfs/osd_io.c
index 9adc20f..b7ad5a0 100644 (file)
--- a/lustre/osd-ldiskfs/osd_io.c
+++ b/lustre/osd-ldiskfs/osd_io.c
@@ -970,7 +970,7 @@ static int osd_ldiskfs_writelink(struct inode *inode, char *buffer, int buflen)
 }
 
 int osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
-                            loff_t *offs, handle_t *handle)
+                            int write_NUL, loff_t *offs, handle_t *handle)
 {
         struct buffer_head *bh        = NULL;
         loff_t              offset    = *offs;
@@ -982,6 +982,15 @@ 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);
@@ -1020,6 +1029,8 @@ 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)) {
                 cfs_spin_lock(&inode->i_lock);
@@ -1044,12 +1055,13 @@ static ssize_t osd_write(const struct lu_env *env, struct dt_object *dt,
                          struct thandle *handle, struct lustre_capa *capa,
                          int ignore_quota)
 {
-        struct inode       *inode = osd_dt_obj(dt)->oo_inode;
-        struct osd_thandle *oh;
-        ssize_t             result;
+       struct inode            *inode = osd_dt_obj(dt)->oo_inode;
+       struct osd_thandle      *oh;
+       ssize_t                 result;
 #ifdef HAVE_QUOTA_SUPPORT
-        cfs_cap_t           save = cfs_curproc_cap_pack();
+       cfs_cap_t               save = cfs_curproc_cap_pack();
 #endif
+       int                     is_link;
 
         LASSERT(dt_object_exists(dt));
 
@@ -1069,16 +1081,18 @@ static ssize_t osd_write(const struct lu_env *env, struct dt_object *dt,
         else
                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 #endif
-        /* Write small symlink to inode body as we need to maintain correct
-         * on-disk symlinks for ldiskfs.
-         */
-        if (S_ISLNK(dt->do_lu.lo_header->loh_attr) &&
-            (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,
-                                                  oh->ot_handle);
+       /* 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.
+        */
+       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, is_link, pos,
+                                                 oh->ot_handle);
 #ifdef HAVE_QUOTA_SUPPORT
         cfs_curproc_cap_unpack(save);
 #endif

diff --git a/lustre/osd-ldiskfs/osd_scrub.c b/lustre/osd-ldiskfs/osd_scrub.c
index e24e54a..5c9a290 100644 (file)
--- a/lustre/osd-ldiskfs/osd_scrub.c
+++ b/lustre/osd-ldiskfs/osd_scrub.c
@@ -214,7 +214,7 @@ int osd_scrub_file_store(struct osd_scrub *scrub)
 
        osd_scrub_file_to_le(&scrub->os_file_disk, &scrub->os_file);
        rc = osd_ldiskfs_write_record(scrub->os_inode, &scrub->os_file_disk,
-                                     len, &pos, jh);
+                                     len, 0, &pos, jh);
        ldiskfs_journal_stop(jh);
        if (rc != 0)
                CERROR("%.16s: fail to store scrub file, expected = %d, "

diff --git a/lustre/tests/sanity.sh b/lustre/tests/sanity.sh
index 1bc10ae..c6f92b8 100644 (file)
--- a/lustre/tests/sanity.sh
+++ b/lustre/tests/sanity.sh
@@ -488,6 +488,59 @@ 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=$($LFS getstripe -M $WDIR)
+       mds_index=$((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