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>

1 files changed, 22 insertions, 22 deletions

diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 4757cef756f7..51bca035cd83 100644
--- 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);