1 files changed, 94 insertions, 101 deletions

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 89556ee72518..1182b66a5491 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -397,6 +397,7 @@ static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf)
         buf->f_namelen = UBIFS_MAX_NLEN;
         buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]);
         buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]);
+        ubifs_assert(buf->f_bfree <= c->block_cnt);
         return 0;
 }
 
@@ -432,33 +433,24 @@ static int ubifs_sync_fs(struct super_block *sb, int wait)
         int i, err;
         struct ubifs_info *c = sb->s_fs_info;
         struct writeback_control wbc = {
-                .sync_mode   = wait ? WB_SYNC_ALL : WB_SYNC_NONE,
+                .sync_mode   = WB_SYNC_ALL,
                 .range_start = 0,
                 .range_end   = LLONG_MAX,
                 .nr_to_write = LONG_MAX,
         };
 
         /*
-         * Note by akpm about WB_SYNC_NONE used above: zero @wait is just an
-         * advisory thing to help the file system shove lots of data into the
-         * queues. If some gets missed then it'll be picked up on the second
+         * Zero @wait is just an advisory thing to help the file system shove
+         * lots of data into the queues, and there will be the second
          * '->sync_fs()' call, with non-zero @wait.
          */
+        if (!wait)
+                return 0;
 
         if (sb->s_flags & MS_RDONLY)
                 return 0;
 
         /*
-         * Synchronize write buffers, because 'ubifs_run_commit()' does not
-         * do this if it waits for an already running commit.
-         */
-        for (i = 0; i < c->jhead_cnt; i++) {
-                err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
-                if (err)
-                        return err;
-        }
-
-        /*
          * VFS calls '->sync_fs()' before synchronizing all dirty inodes and
          * pages, so synchronize them first, then commit the journal. Strictly
          * speaking, it is not necessary to commit the journal here,
@@ -469,6 +461,16 @@ static int ubifs_sync_fs(struct super_block *sb, int wait)
          */
         generic_sync_sb_inodes(sb, &wbc);
 
+        /*
+         * Synchronize write buffers, because 'ubifs_run_commit()' does not
+         * do this if it waits for an already running commit.
+         */
+        for (i = 0; i < c->jhead_cnt; i++) {
+                err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
+                if (err)
+                        return err;
+        }
+
         err = ubifs_run_commit(c);
         if (err)
                 return err;
@@ -572,15 +574,8 @@ static int init_constants_early(struct ubifs_info *c)
         c->ranges[UBIFS_IDX_NODE].max_len = INT_MAX;
 
         /*
-         * Initialize dead and dark LEB space watermarks.
-         *
-         * Dead space is the space which cannot be used. Its watermark is
-         * equivalent to min. I/O unit or minimum node size if it is greater
-         * then min. I/O unit.
-         *
-         * Dark space is the space which might be used, or might not, depending
-         * on which node should be written to the LEB. Its watermark is
-         * equivalent to maximum UBIFS node size.
+         * Initialize dead and dark LEB space watermarks. See gc.c for comments
+         * about these values.
          */
         c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size);
         c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_size);
@@ -741,12 +736,12 @@ static void init_constants_master(struct ubifs_info *c)
  * take_gc_lnum - reserve GC LEB.
  * @c: UBIFS file-system description object
  *
- * This function ensures that the LEB reserved for garbage collection is
- * unmapped and is marked as "taken" in lprops. We also have to set free space
- * to LEB size and dirty space to zero, because lprops may contain out-of-date
- * information if the file-system was un-mounted before it has been committed.
- * This function returns zero in case of success and a negative error code in
- * case of failure.
+ * This function ensures that the LEB reserved for garbage collection is marked
+ * as "taken" in lprops. We also have to set free space to LEB size and dirty
+ * space to zero, because lprops may contain out-of-date information if the
+ * file-system was un-mounted before it has been committed. This function
+ * returns zero in case of success and a negative error code in case of
+ * failure.
  */
 static int take_gc_lnum(struct ubifs_info *c)
 {
@@ -757,10 +752,6 @@ static int take_gc_lnum(struct ubifs_info *c)
                 return -EINVAL;
         }
 
-        err = ubifs_leb_unmap(c, c->gc_lnum);
-        if (err)
-                return err;
-
         /* And we have to tell lprops that this LEB is taken */
         err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0,
                                   LPROPS_TAKEN, 0, 0);
@@ -966,13 +957,16 @@ static int ubifs_parse_options(struct ubifs_info *c, char *options,
 
                 token = match_token(p, tokens, args);
                 switch (token) {
+                /*
+                 * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
+                 * We accepte them in order to be backware-compatible. But this
+                 * should be removed at some point.
+                 */
                 case Opt_fast_unmount:
                         c->mount_opts.unmount_mode = 2;
-                        c->fast_unmount = 1;
                         break;
                 case Opt_norm_unmount:
                         c->mount_opts.unmount_mode = 1;
-                        c->fast_unmount = 0;
                         break;
                 case Opt_bulk_read:
                         c->mount_opts.bulk_read = 2;
@@ -1094,12 +1088,7 @@ static int check_free_space(struct ubifs_info *c)
                 ubifs_err("insufficient free space to mount in read/write mode");
                 dbg_dump_budg(c);
                 dbg_dump_lprops(c);
-                /*
-                 * We return %-EINVAL instead of %-ENOSPC because it seems to
-                 * be the closest error code mentioned in the mount function
-                 * documentation.
-                 */
-                return -EINVAL;
+                return -ENOSPC;
         }
         return 0;
 }
@@ -1286,10 +1275,19 @@ static int mount_ubifs(struct ubifs_info *c)
                         if (err)
                                 goto out_orphans;
                         err = ubifs_rcvry_gc_commit(c);
-                } else
+                } else {
                         err = take_gc_lnum(c);
-                if (err)
-                        goto out_orphans;
+                        if (err)
+                                goto out_orphans;
+
+                        /*
+                         * GC LEB may contain garbage if there was an unclean
+                         * reboot, and it should be un-mapped.
+                         */
+                        err = ubifs_leb_unmap(c, c->gc_lnum);
+                        if (err)
+                                return err;
+                }
 
                 err = dbg_check_lprops(c);
                 if (err)
@@ -1298,6 +1296,16 @@ static int mount_ubifs(struct ubifs_info *c)
                 err = ubifs_recover_size(c);
                 if (err)
                         goto out_orphans;
+        } else {
+                /*
+                 * Even if we mount read-only, we have to set space in GC LEB
+                 * to proper value because this affects UBIFS free space
+                 * reporting. We do not want to have a situation when
+                 * re-mounting from R/O to R/W changes amount of free space.
+                 */
+                err = take_gc_lnum(c);
+                if (err)
+                        goto out_orphans;
         }
 
         spin_lock(&ubifs_infos_lock);
@@ -1310,14 +1318,17 @@ static int mount_ubifs(struct ubifs_info *c)
                 else {
                         c->need_recovery = 0;
                         ubifs_msg("recovery completed");
+                        /* GC LEB has to be empty and taken at this point */
+                        ubifs_assert(c->lst.taken_empty_lebs == 1);
                 }
-        }
+        } else
+                ubifs_assert(c->lst.taken_empty_lebs == 1);
 
-        err = dbg_debugfs_init_fs(c);
+        err = dbg_check_filesystem(c);
         if (err)
                 goto out_infos;
 
-        err = dbg_check_filesystem(c);
+        err = dbg_debugfs_init_fs(c);
         if (err)
                 goto out_infos;
 
@@ -1351,7 +1362,6 @@ static int mount_ubifs(struct ubifs_info *c)
                c->uuid[4], c->uuid[5], c->uuid[6], c->uuid[7],
                c->uuid[8], c->uuid[9], c->uuid[10], c->uuid[11],
                c->uuid[12], c->uuid[13], c->uuid[14], c->uuid[15]);
-        dbg_msg("fast unmount:        %d", c->fast_unmount);
         dbg_msg("big_lpt              %d", c->big_lpt);
         dbg_msg("log LEBs:            %d (%d - %d)",
                 c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
@@ -1475,10 +1485,8 @@ static int ubifs_remount_rw(struct ubifs_info *c)
 {
         int err, lnum;
 
-        if (c->ro_media)
-                return -EINVAL;
-
         mutex_lock(&c->umount_mutex);
+        dbg_save_space_info(c);
         c->remounting_rw = 1;
         c->always_chk_crc = 1;
 
@@ -1514,6 +1522,12 @@ static int ubifs_remount_rw(struct ubifs_info *c)
                 err = ubifs_recover_inl_heads(c, c->sbuf);
                 if (err)
                         goto out;
+        } else {
+                /* A readonly mount is not allowed to have orphans */
+                ubifs_assert(c->tot_orphans == 0);
+                err = ubifs_clear_orphans(c);
+                if (err)
+                        goto out;
         }
 
         if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
@@ -1569,7 +1583,7 @@ static int ubifs_remount_rw(struct ubifs_info *c)
         if (c->need_recovery)
                 err = ubifs_rcvry_gc_commit(c);
         else
-                err = take_gc_lnum(c);
+                err = ubifs_leb_unmap(c, c->gc_lnum);
         if (err)
                 goto out;
 
@@ -1582,8 +1596,9 @@ static int ubifs_remount_rw(struct ubifs_info *c)
         c->vfs_sb->s_flags &= ~MS_RDONLY;
         c->remounting_rw = 0;
         c->always_chk_crc = 0;
+        err = dbg_check_space_info(c);
         mutex_unlock(&c->umount_mutex);
-        return 0;
+        return err;
 
 out:
         vfree(c->orph_buf);
@@ -1603,43 +1618,18 @@ out:
 }
 
 /**
- * commit_on_unmount - commit the journal when un-mounting.
- * @c: UBIFS file-system description object
- *
- * This function is called during un-mounting and re-mounting, and it commits
- * the journal unless the "fast unmount" mode is enabled.
- */
-static void commit_on_unmount(struct ubifs_info *c)
-{
-        struct super_block *sb = c->vfs_sb;
-        long long bud_bytes;
-
-        /*
-         * This function is called before the background thread is stopped, so
-         * we may race with ongoing commit, which means we have to take
-         * @c->bud_lock to access @c->bud_bytes.
-         */
-        spin_lock(&c->buds_lock);
-        bud_bytes = c->bud_bytes;
-        spin_unlock(&c->buds_lock);
-
-        if (!c->fast_unmount && !(sb->s_flags & MS_RDONLY) && bud_bytes)
-                ubifs_run_commit(c);
-}
-
-/**
  * ubifs_remount_ro - re-mount in read-only mode.
  * @c: UBIFS file-system description object
  *
- * We rely on VFS to have stopped writing. Possibly the background thread could
- * be running a commit, however kthread_stop will wait in that case.
+ * We assume VFS has stopped writing. Possibly the background thread could be
+ * running a commit, however kthread_stop will wait in that case.
  */
 static void ubifs_remount_ro(struct ubifs_info *c)
 {
         int i, err;
 
         ubifs_assert(!c->need_recovery);
-        commit_on_unmount(c);
+        ubifs_assert(!(c->vfs_sb->s_flags & MS_RDONLY));
 
         mutex_lock(&c->umount_mutex);
         if (c->bgt) {
@@ -1647,27 +1637,29 @@ static void ubifs_remount_ro(struct ubifs_info *c)
                 c->bgt = NULL;
         }
 
+        dbg_save_space_info(c);
+
         for (i = 0; i < c->jhead_cnt; i++) {
                 ubifs_wbuf_sync(&c->jheads[i].wbuf);
                 del_timer_sync(&c->jheads[i].wbuf.timer);
         }
 
-        if (!c->ro_media) {
-                c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
-                c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
-                c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
-                err = ubifs_write_master(c);
-                if (err)
-                        ubifs_ro_mode(c, err);
-        }
+        c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
+        c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
+        c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
+        err = ubifs_write_master(c);
+        if (err)
+                ubifs_ro_mode(c, err);
 
-        ubifs_destroy_idx_gc(c);
         free_wbufs(c);
         vfree(c->orph_buf);
         c->orph_buf = NULL;
         vfree(c->ileb_buf);
         c->ileb_buf = NULL;
         ubifs_lpt_free(c, 1);
+        err = dbg_check_space_info(c);
+        if (err)
+                ubifs_ro_mode(c, err);
         mutex_unlock(&c->umount_mutex);
 }
 
@@ -1760,11 +1752,20 @@ static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
         }
 
         if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
+                if (c->ro_media) {
+                        ubifs_msg("cannot re-mount due to prior errors");
+                        return -EROFS;
+                }
                 err = ubifs_remount_rw(c);
                 if (err)
                         return err;
-        } else if (!(sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY))
+        } else if (!(sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY)) {
+                if (c->ro_media) {
+                        ubifs_msg("cannot re-mount due to prior errors");
+                        return -EROFS;
+                }
                 ubifs_remount_ro(c);
+        }
 
         if (c->bulk_read == 1)
                 bu_init(c);
@@ -1774,10 +1775,11 @@ static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
                 c->bu.buf = NULL;
         }
 
+        ubifs_assert(c->lst.taken_empty_lebs == 1);
         return 0;
 }
 
-struct super_operations ubifs_super_operations = {
+const struct super_operations ubifs_super_operations = {
         .alloc_inode   = ubifs_alloc_inode,
         .destroy_inode = ubifs_destroy_inode,
         .put_super     = ubifs_put_super,
@@ -2044,15 +2046,6 @@ out_close:
 
 static void ubifs_kill_sb(struct super_block *sb)
 {
-        struct ubifs_info *c = sb->s_fs_info;
-
-        /*
-         * We do 'commit_on_unmount()' here instead of 'ubifs_put_super()'
-         * in order to be outside BKL.
-         */
-        if (sb->s_root)
-                commit_on_unmount(c);
-        /* The un-mount routine is actually done in put_super() */
         generic_shutdown_super(sb);
 }