LU-1540 osd: add NUL terminator for long symlink

[fs/lustre-release.git] / lustre / osd-ldiskfs / osd_io.c

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