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Message-Id: <1474037966-5524-13-git-send-email-boris.brezillon@free-electrons.com>
Date: Fri, 16 Sep 2016 16:59:20 +0200
From: Boris Brezillon <boris.brezillon@...e-electrons.com>
To: Artem Bityutskiy <dedekind1@...il.com>,
Richard Weinberger <richard@....at>
Cc: David Woodhouse <dwmw2@...radead.org>,
Brian Norris <computersforpeace@...il.com>,
linux-mtd@...ts.infradead.org, linux-kernel@...r.kernel.org,
Boris Brezillon <boris.brezillon@...e-electrons.com>
Subject: [PATCH v3 12/18] UBI: simplify recover_peb() code
recover_peb() is using a convoluted retry/exit path. Add try_recover_peb()
to simplify the retry logic and make sure we have a single exit path
instead of manually releasing the resource in each error path.
Signed-off-by: Boris Brezillon <boris.brezillon@...e-electrons.com>
---
drivers/mtd/ubi/eba.c | 130 ++++++++++++++++++++++++++++++--------------------
1 file changed, 77 insertions(+), 53 deletions(-)
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index ebf517271d29..be59cfb81934 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -554,39 +554,37 @@ int ubi_eba_read_leb_sg(struct ubi_device *ubi, struct ubi_volume *vol,
}
/**
- * recover_peb - recover from write failure.
- * @ubi: UBI device description object
+ * try_recover_peb - try to recover from write failure.
+ * @vol: volume description object
* @pnum: the physical eraseblock to recover
- * @vol_id: volume ID
* @lnum: logical eraseblock number
* @buf: data which was not written because of the write failure
* @offset: offset of the failed write
* @len: how many bytes should have been written
+ * @vid: VID header
+ * @retry: whether the caller should retry in case of failure
*
* This function is called in case of a write failure and moves all good data
* from the potentially bad physical eraseblock to a good physical eraseblock.
* This function also writes the data which was not written due to the failure.
- * Returns new physical eraseblock number in case of success, and a negative
- * error code in case of failure.
+ * Returns 0 in case of success, and a negative error code in case of failure.
+ * In case of failure, the %retry parameter is set to false if this is a fatal
+ * error (retrying won't help), and true otherwise.
*/
-static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
- const void *buf, int offset, int len)
+static int try_recover_peb(struct ubi_volume *vol, int pnum, int lnum,
+ const void *buf, int offset, int len,
+ struct ubi_vid_hdr *vid_hdr, bool *retry)
{
- int err, idx = vol_id2idx(ubi, vol_id), new_pnum, data_size, tries = 0;
- struct ubi_volume *vol = ubi->volumes[idx];
- struct ubi_vid_hdr *vid_hdr;
+ struct ubi_device *ubi = vol->ubi;
+ int new_pnum, err, vol_id = vol->vol_id, data_size;
uint32_t crc;
- vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
- if (!vid_hdr)
- return -ENOMEM;
+ *retry = false;
-retry:
new_pnum = ubi_wl_get_peb(ubi);
if (new_pnum < 0) {
- ubi_free_vid_hdr(ubi, vid_hdr);
- up_read(&ubi->fm_eba_sem);
- return new_pnum;
+ err = new_pnum;
+ goto out_put;
}
ubi_msg(ubi, "recover PEB %d, move data to PEB %d",
@@ -596,7 +594,6 @@ retry:
if (err && err != UBI_IO_BITFLIPS) {
if (err > 0)
err = -EIO;
- up_read(&ubi->fm_eba_sem);
goto out_put;
}
@@ -608,12 +605,12 @@ retry:
/* Read everything before the area where the write failure happened */
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_eba_sem);
+ if (err && err != UBI_IO_BITFLIPS)
goto out_unlock;
- }
}
+ *retry = true;
+
memcpy(ubi->peb_buf + offset, buf, len);
data_size = offset + len;
@@ -623,49 +620,76 @@ retry:
vid_hdr->data_size = cpu_to_be32(data_size);
vid_hdr->data_crc = cpu_to_be32(crc);
err = ubi_io_write_vid_hdr(ubi, new_pnum, vid_hdr);
- if (err) {
- mutex_unlock(&ubi->buf_mutex);
- up_read(&ubi->fm_eba_sem);
- goto write_error;
- }
+ if (err)
+ goto out_unlock;
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_eba_sem);
- goto write_error;
- }
+out_unlock:
mutex_unlock(&ubi->buf_mutex);
- ubi_free_vid_hdr(ubi, vid_hdr);
- vol->eba_tbl[lnum] = new_pnum;
+ if (!err)
+ vol->eba_tbl[lnum] = new_pnum;
+
+out_put:
up_read(&ubi->fm_eba_sem);
- ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1);
- ubi_msg(ubi, "data was successfully recovered");
- return 0;
+ if (!err) {
+ ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1);
+ ubi_msg(ubi, "data was successfully recovered");
+ } else if (new_pnum >= 0) {
+ /*
+ * Bad luck? This physical eraseblock is bad too? Crud. Let's
+ * try to get another one.
+ */
+ ubi_wl_put_peb(ubi, vol_id, lnum, new_pnum, 1);
+ ubi_warn(ubi, "failed to write to PEB %d", new_pnum);
+ }
-out_unlock:
- mutex_unlock(&ubi->buf_mutex);
-out_put:
- ubi_wl_put_peb(ubi, vol_id, lnum, new_pnum, 1);
- ubi_free_vid_hdr(ubi, vid_hdr);
return err;
+}
-write_error:
- /*
- * Bad luck? This physical eraseblock is bad too? Crud. Let's try to
- * get another one.
- */
- ubi_warn(ubi, "failed to write to PEB %d", new_pnum);
- ubi_wl_put_peb(ubi, vol_id, lnum, new_pnum, 1);
- if (++tries > UBI_IO_RETRIES) {
- ubi_free_vid_hdr(ubi, vid_hdr);
- return err;
+/**
+ * recover_peb - recover from write failure.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock to recover
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ * @buf: data which was not written because of the write failure
+ * @offset: offset of the failed write
+ * @len: how many bytes should have been written
+ *
+ * This function is called in case of a write failure and moves all good data
+ * from the potentially bad physical eraseblock to a good physical eraseblock.
+ * This function also writes the data which was not written due to the failure.
+ * Returns 0 in case of success, and a negative error code in case of failure.
+ * This function tries %UBI_IO_RETRIES before giving up.
+ */
+static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
+ const void *buf, int offset, int len)
+{
+ int err, idx = vol_id2idx(ubi, vol_id), tries;
+ struct ubi_volume *vol = ubi->volumes[idx];
+ struct ubi_vid_hdr *vid_hdr;
+
+ vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
+ if (!vid_hdr)
+ return -ENOMEM;
+
+ for (tries = 0; tries <= UBI_IO_RETRIES; tries++) {
+ bool retry;
+
+ err = try_recover_peb(vol, pnum, lnum, buf, offset, len,
+ vid_hdr, &retry);
+ if (!err || !retry)
+ break;
+
+ ubi_msg(ubi, "try again");
}
- ubi_msg(ubi, "try again");
- goto retry;
+
+ ubi_free_vid_hdr(ubi, vid_hdr);
+
+ return err;
}
/**
--
2.7.4
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