UBI: use separate mutex for volumes checking

Introduce a separate mutex which serializes volumes checking,
because we cammot really use volumes_mutex - it cases reverse
locking problems with mtd_tbl_mutex when gluebi is used -
thanks to lockdep.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 70c0b9a..6ac1339 100644 (file)
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -703,6 +703,7 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
                goto out_free;
 
        mutex_init(&ubi->buf_mutex);
+       mutex_init(&ubi->ckvol_mutex);
        ubi->peb_buf1 = vmalloc(ubi->peb_size);
        if (!ubi->peb_buf1)
                goto out_free;

diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c
index 4ec3a33..146957c 100644 (file)
--- a/drivers/mtd/ubi/kapi.c
+++ b/drivers/mtd/ubi/kapi.c
@@ -169,17 +169,12 @@ struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
        desc->vol = vol;
        desc->mode = mode;
 
-       /*
-        * To prevent simultaneous checks of the same volume we use
-        * @volumes_mutex, although it is not the purpose it was introduced
-        * for.
-        */
-       mutex_lock(&ubi->volumes_mutex);
+       mutex_lock(&ubi->ckvol_mutex);
        if (!vol->checked) {
                /* This is the first open - check the volume */
                err = ubi_check_volume(ubi, vol_id);
                if (err < 0) {
-                       mutex_unlock(&ubi->volumes_mutex);
+                       mutex_unlock(&ubi->ckvol_mutex);
                        ubi_close_volume(desc);
                        return ERR_PTR(err);
                }
@@ -190,7 +185,7 @@ struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
                }
                vol->checked = 1;
        }
-       mutex_unlock(&ubi->volumes_mutex);
+       mutex_unlock(&ubi->ckvol_mutex);
 
        return desc;
 

diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 2a61712..ef22f92 100644 (file)
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -392,6 +392,7 @@ struct ubi_device {
        void *peb_buf1;
        void *peb_buf2;
        struct mutex buf_mutex;
+       struct mutex ckvol_mutex;
 #ifdef CONFIG_MTD_UBI_DEBUG
        void *dbg_peb_buf;
        struct mutex dbg_buf_mutex;