UBI: Fastmap: Locking updates

a) Rename ubi->fm_sem to ubi->fm_eba_sem as this semaphore
protects EBA changes.
b) Turn ubi->fm_mutex into a rw semaphore. It will still serialize
fastmap writes but also ensures that ubi_wl_put_peb() is not
interrupted by a fastmap write. We use a rw semaphore to allow
ubi_wl_put_peb() still to be executed in parallel if no fastmap
write is happening.

Signed-off-by: Richard Weinberger <richard@nod.at>

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 59af91b..a757150 100644 (file)
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -969,8 +969,8 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
        mutex_init(&ubi->ckvol_mutex);
        mutex_init(&ubi->device_mutex);
        spin_lock_init(&ubi->volumes_lock);
-       mutex_init(&ubi->fm_mutex);
-       init_rwsem(&ubi->fm_sem);
+       init_rwsem(&ubi->fm_protect);
+       init_rwsem(&ubi->fm_eba_sem);
 
        ubi_msg(ubi, "attaching mtd%d", mtd->index);
 

diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 4757cef..51bca03 100644 (file)
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -340,9 +340,9 @@ int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
 
        dbg_eba("erase LEB %d:%d, PEB %d", vol_id, lnum, pnum);
 
-       down_read(&ubi->fm_sem);
+       down_read(&ubi->fm_eba_sem);
        vol->eba_tbl[lnum] = UBI_LEB_UNMAPPED;
-       up_read(&ubi->fm_sem);
+       up_read(&ubi->fm_eba_sem);
        err = ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 0);
 
 out_unlock:
@@ -567,7 +567,7 @@ retry:
        new_pnum = ubi_wl_get_peb(ubi);
        if (new_pnum < 0) {
                ubi_free_vid_hdr(ubi, vid_hdr);
-               up_read(&ubi->fm_sem);
+               up_read(&ubi->fm_eba_sem);
                return new_pnum;
        }
 
@@ -578,14 +578,14 @@ retry:
        if (err && err != UBI_IO_BITFLIPS) {
                if (err > 0)
                        err = -EIO;
-               up_read(&ubi->fm_sem);
+               up_read(&ubi->fm_eba_sem);
                goto out_put;
        }
 
        vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
        err = ubi_io_write_vid_hdr(ubi, new_pnum, vid_hdr);
        if (err) {
-               up_read(&ubi->fm_sem);
+               up_read(&ubi->fm_eba_sem);
                goto write_error;
        }
 
@@ -597,7 +597,7 @@ retry:
        if (offset > 0) {
                err = ubi_io_read_data(ubi, ubi->peb_buf, pnum, 0, offset);
                if (err && err != UBI_IO_BITFLIPS) {
-                       up_read(&ubi->fm_sem);
+                       up_read(&ubi->fm_eba_sem);
                        goto out_unlock;
                }
        }
@@ -607,7 +607,7 @@ retry:
        err = ubi_io_write_data(ubi, ubi->peb_buf, new_pnum, 0, data_size);
        if (err) {
                mutex_unlock(&ubi->buf_mutex);
-               up_read(&ubi->fm_sem);
+               up_read(&ubi->fm_eba_sem);
                goto write_error;
        }
 
@@ -615,7 +615,7 @@ retry:
        ubi_free_vid_hdr(ubi, vid_hdr);
 
        vol->eba_tbl[lnum] = new_pnum;
-       up_read(&ubi->fm_sem);
+       up_read(&ubi->fm_eba_sem);
        ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1);
 
        ubi_msg(ubi, "data was successfully recovered");
@@ -710,7 +710,7 @@ retry:
        if (pnum < 0) {
                ubi_free_vid_hdr(ubi, vid_hdr);
                leb_write_unlock(ubi, vol_id, lnum);
-               up_read(&ubi->fm_sem);
+               up_read(&ubi->fm_eba_sem);
                return pnum;
        }
 
@@ -721,7 +721,7 @@ retry:
        if (err) {
                ubi_warn(ubi, "failed to write VID header to LEB %d:%d, PEB %d",
                         vol_id, lnum, pnum);
-               up_read(&ubi->fm_sem);
+               up_read(&ubi->fm_eba_sem);
                goto write_error;
        }
 
@@ -730,13 +730,13 @@ retry:
                if (err) {
                        ubi_warn(ubi, "failed to write %d bytes at offset %d of LEB %d:%d, PEB %d",
                                 len, offset, vol_id, lnum, pnum);
-                       up_read(&ubi->fm_sem);
+                       up_read(&ubi->fm_eba_sem);
                        goto write_error;
                }
        }
 
        vol->eba_tbl[lnum] = pnum;
-       up_read(&ubi->fm_sem);
+       up_read(&ubi->fm_eba_sem);
 
        leb_write_unlock(ubi, vol_id, lnum);
        ubi_free_vid_hdr(ubi, vid_hdr);
@@ -833,7 +833,7 @@ retry:
        if (pnum < 0) {
                ubi_free_vid_hdr(ubi, vid_hdr);
                leb_write_unlock(ubi, vol_id, lnum);
-               up_read(&ubi->fm_sem);
+               up_read(&ubi->fm_eba_sem);
                return pnum;
        }
 
@@ -844,7 +844,7 @@ retry:
        if (err) {
                ubi_warn(ubi, "failed to write VID header to LEB %d:%d, PEB %d",
                         vol_id, lnum, pnum);
-               up_read(&ubi->fm_sem);
+               up_read(&ubi->fm_eba_sem);
                goto write_error;
        }
 
@@ -852,13 +852,13 @@ retry:
        if (err) {
                ubi_warn(ubi, "failed to write %d bytes of data to PEB %d",
                         len, pnum);
-               up_read(&ubi->fm_sem);
+               up_read(&ubi->fm_eba_sem);
                goto write_error;
        }
 
        ubi_assert(vol->eba_tbl[lnum] < 0);
        vol->eba_tbl[lnum] = pnum;
-       up_read(&ubi->fm_sem);
+       up_read(&ubi->fm_eba_sem);
 
        leb_write_unlock(ubi, vol_id, lnum);
        ubi_free_vid_hdr(ubi, vid_hdr);
@@ -953,7 +953,7 @@ retry:
        pnum = ubi_wl_get_peb(ubi);
        if (pnum < 0) {
                err = pnum;
-               up_read(&ubi->fm_sem);
+               up_read(&ubi->fm_eba_sem);
                goto out_leb_unlock;
        }
 
@@ -964,7 +964,7 @@ retry:
        if (err) {
                ubi_warn(ubi, "failed to write VID header to LEB %d:%d, PEB %d",
                         vol_id, lnum, pnum);
-               up_read(&ubi->fm_sem);
+               up_read(&ubi->fm_eba_sem);
                goto write_error;
        }
 
@@ -972,13 +972,13 @@ retry:
        if (err) {
                ubi_warn(ubi, "failed to write %d bytes of data to PEB %d",
                         len, pnum);
-               up_read(&ubi->fm_sem);
+               up_read(&ubi->fm_eba_sem);
                goto write_error;
        }
 
        old_pnum = vol->eba_tbl[lnum];
        vol->eba_tbl[lnum] = pnum;
-       up_read(&ubi->fm_sem);
+       up_read(&ubi->fm_eba_sem);
 
        if (old_pnum >= 0) {
                err = ubi_wl_put_peb(ubi, vol_id, lnum, old_pnum, 0);
@@ -1231,9 +1231,9 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
        }
 
        ubi_assert(vol->eba_tbl[lnum] == from);
-       down_read(&ubi->fm_sem);
+       down_read(&ubi->fm_eba_sem);
        vol->eba_tbl[lnum] = to;
-       up_read(&ubi->fm_sem);
+       up_read(&ubi->fm_eba_sem);
 
 out_unlock_buf:
        mutex_unlock(&ubi->buf_mutex);

diff --cc drivers/mtd/ubi/fastmap.c
Simple merge

diff --cc drivers/mtd/ubi/ubi.h
Simple merge

diff --cc drivers/mtd/ubi/wl.c
Simple merge