Merge branch 'for-linus' of git://git.infradead.org/ubifs-2.6

* 'for-linus' of git://git.infradead.org/ubifs-2.6:
  UBI: do not select KALLSYMS_ALL
  UBI: do not compare array with NULL
  UBI: check if we are in RO mode in the erase routine
  UBIFS: fix debugging failure in dbg_check_space_info
  UBIFS: fix error path in dbg_debugfs_init_fs
  UBIFS: unify error path dbg_debugfs_init_fs
  UBIFS: do not select KALLSYMS_ALL
  UBIFS: fix assertion warnings
  UBIFS: fix oops on error path in read_pnode
  UBIFS: do not read flash unnecessarily

5 files changed, 53 insertions, 24 deletions

diff --git a/fs/ubifs/Kconfig b/fs/ubifs/Kconfig
index d7440904be17..f8b0160da2da 100644
--- a/fs/ubifs/Kconfig
+++ b/fs/ubifs/Kconfig
@@ -47,7 +47,7 @@ config UBIFS_FS_DEBUG
         bool "Enable debugging support"
         depends on UBIFS_FS
         select DEBUG_FS
-        select KALLSYMS_ALL
+        select KALLSYMS
         help
           This option enables UBIFS debugging support. It makes sure various
           assertions, self-checks, debugging messages and test modes are compiled
diff --git a/fs/ubifs/commit.c b/fs/ubifs/commit.c
index b148fbc80f8d..1bd01ded7123 100644
--- a/fs/ubifs/commit.c
+++ b/fs/ubifs/commit.c
@@ -577,7 +577,7 @@ int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot)
         size_t sz;
 
         if (!(ubifs_chk_flags & UBIFS_CHK_OLD_IDX))
-                goto out;
+                return 0;
 
         INIT_LIST_HEAD(&list);
 
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index f25a7339f800..004d3745dc45 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -972,11 +972,39 @@ void dbg_dump_index(struct ubifs_info *c)
 void dbg_save_space_info(struct ubifs_info *c)
 {
         struct ubifs_debug_info *d = c->dbg;
-
-        ubifs_get_lp_stats(c, &d->saved_lst);
+        int freeable_cnt;
 
         spin_lock(&c->space_lock);
+        memcpy(&d->saved_lst, &c->lst, sizeof(struct ubifs_lp_stats));
+
+        /*
+         * We use a dirty hack here and zero out @c->freeable_cnt, because it
+         * affects the free space calculations, and UBIFS might not know about
+         * all freeable eraseblocks. Indeed, we know about freeable eraseblocks
+         * only when we read their lprops, and we do this only lazily, upon the
+         * need. So at any given point of time @c->freeable_cnt might be not
+         * exactly accurate.
+         *
+         * Just one example about the issue we hit when we did not zero
+         * @c->freeable_cnt.
+         * 1. The file-system is mounted R/O, c->freeable_cnt is %0. We save the
+         *    amount of free space in @d->saved_free
+         * 2. We re-mount R/W, which makes UBIFS to read the "lsave"
+         *    information from flash, where we cache LEBs from various
+         *    categories ('ubifs_remount_fs()' -> 'ubifs_lpt_init()'
+         *    -> 'lpt_init_wr()' -> 'read_lsave()' -> 'ubifs_lpt_lookup()'
+         *    -> 'ubifs_get_pnode()' -> 'update_cats()'
+         *    -> 'ubifs_add_to_cat()').
+         * 3. Lsave contains a freeable eraseblock, and @c->freeable_cnt
+         *    becomes %1.
+         * 4. We calculate the amount of free space when the re-mount is
+         *    finished in 'dbg_check_space_info()' and it does not match
+         *    @d->saved_free.
+         */
+        freeable_cnt = c->freeable_cnt;
+        c->freeable_cnt = 0;
         d->saved_free = ubifs_get_free_space_nolock(c);
+        c->freeable_cnt = freeable_cnt;
         spin_unlock(&c->space_lock);
 }
 
@@ -993,12 +1021,15 @@ int dbg_check_space_info(struct ubifs_info *c)
 {
         struct ubifs_debug_info *d = c->dbg;
         struct ubifs_lp_stats lst;
-        long long avail, free;
+        long long free;
+        int freeable_cnt;
 
         spin_lock(&c->space_lock);
-        avail = ubifs_calc_available(c, c->min_idx_lebs);
+        freeable_cnt = c->freeable_cnt;
+        c->freeable_cnt = 0;
+        free = ubifs_get_free_space_nolock(c);
+        c->freeable_cnt = freeable_cnt;
         spin_unlock(&c->space_lock);
-        free = ubifs_get_free_space(c);
 
         if (free != d->saved_free) {
                 ubifs_err("free space changed from %lld to %lld",
@@ -2806,40 +2837,38 @@ int dbg_debugfs_init_fs(struct ubifs_info *c)
         struct ubifs_debug_info *d = c->dbg;
 
         sprintf(d->dfs_dir_name, "ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
-        d->dfs_dir = debugfs_create_dir(d->dfs_dir_name, dfs_rootdir);
-        if (IS_ERR(d->dfs_dir)) {
-                err = PTR_ERR(d->dfs_dir);
-                ubifs_err("cannot create \"%s\" debugfs directory, error %d\n",
-                          d->dfs_dir_name, err);
+        fname = d->dfs_dir_name;
+        dent = debugfs_create_dir(fname, dfs_rootdir);
+        if (IS_ERR_OR_NULL(dent))
                 goto out;
-        }
+        d->dfs_dir = dent;
 
         fname = "dump_lprops";
         dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, c, &dfs_fops);
-        if (IS_ERR(dent))
+        if (IS_ERR_OR_NULL(dent))
                 goto out_remove;
         d->dfs_dump_lprops = dent;
 
         fname = "dump_budg";
         dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, c, &dfs_fops);
-        if (IS_ERR(dent))
+        if (IS_ERR_OR_NULL(dent))
                 goto out_remove;
         d->dfs_dump_budg = dent;
 
         fname = "dump_tnc";
         dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, c, &dfs_fops);
-        if (IS_ERR(dent))
+        if (IS_ERR_OR_NULL(dent))
                 goto out_remove;
         d->dfs_dump_tnc = dent;
 
         return 0;
 
 out_remove:
-        err = PTR_ERR(dent);
-        ubifs_err("cannot create \"%s\" debugfs directory, error %d\n",
-                  fname, err);
         debugfs_remove_recursive(d->dfs_dir);
 out:
+        err = dent ? PTR_ERR(dent) : -ENODEV;
+        ubifs_err("cannot create \"%s\" debugfs directory, error %d\n",
+                  fname, err);
         return err;
 }
 
diff --git a/fs/ubifs/lpt.c b/fs/ubifs/lpt.c
index 72775d35b99e..ef5155e109a2 100644
--- a/fs/ubifs/lpt.c
+++ b/fs/ubifs/lpt.c
@@ -1270,10 +1270,9 @@ static int read_pnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
         lnum = branch->lnum;
         offs = branch->offs;
         pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_NOFS);
-        if (!pnode) {
-                err = -ENOMEM;
-                goto out;
-        }
+        if (!pnode)
+                return -ENOMEM;
+
         if (lnum == 0) {
                 /*
                  * This pnode was not written which just means that the LEB
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 6ddd9973e681..c75f6133206c 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1568,6 +1568,7 @@ static int ubifs_remount_rw(struct ubifs_info *c)
         mutex_lock(&c->umount_mutex);
         dbg_save_space_info(c);
         c->remounting_rw = 1;
+        c->ro_mount = 0;
 
         err = check_free_space(c);
         if (err)
@@ -1676,13 +1677,13 @@ static int ubifs_remount_rw(struct ubifs_info *c)
         }
 
         dbg_gen("re-mounted read-write");
-        c->ro_mount = 0;
         c->remounting_rw = 0;
         err = dbg_check_space_info(c);
         mutex_unlock(&c->umount_mutex);
         return err;
 
 out:
+        c->ro_mount = 1;
         vfree(c->orph_buf);
         c->orph_buf = NULL;
         if (c->bgt) {