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UBI: simplify recover_peb() code

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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@free-electrons.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This commit is contained in:
Boris Brezillon 2016-09-16 16:59:20 +02:00 committed by Richard Weinberger
parent 7b6b749b12
commit f036dfeb85
1 changed files with 108 additions and 84 deletions
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192
drivers/mtd/ubi/eba.c
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@ -553,6 +553,102 @@ int ubi_eba_read_leb_sg(struct ubi_device *ubi, struct ubi_volume *vol,
return ret; return ret;
} }
/**
* try_recover_peb - try to recover from write failure.
* @vol: volume description object
* @pnum: the physical eraseblock to recover
* @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 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 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)
{
struct ubi_device *ubi = vol->ubi;
int new_pnum, err, vol_id = vol->vol_id, data_size;
uint32_t crc;
*retry = false;
new_pnum = ubi_wl_get_peb(ubi);
if (new_pnum < 0) {
err = new_pnum;
goto out_put;
}
ubi_msg(ubi, "recover PEB %d, move data to PEB %d",
pnum, new_pnum);
err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1);
if (err && err != UBI_IO_BITFLIPS) {
if (err > 0)
err = -EIO;
goto out_put;
}
ubi_assert(vid_hdr->vol_type == UBI_VID_DYNAMIC);
mutex_lock(&ubi->buf_mutex);
memset(ubi->peb_buf + offset, 0xFF, len);
/* 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)
goto out_unlock;
}
*retry = true;
memcpy(ubi->peb_buf + offset, buf, len);
data_size = offset + len;
crc = crc32(UBI_CRC32_INIT, ubi->peb_buf, data_size);
vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
vid_hdr->copy_flag = 1;
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)
goto out_unlock;
err = ubi_io_write_data(ubi, ubi->peb_buf, new_pnum, 0, data_size);
out_unlock:
mutex_unlock(&ubi->buf_mutex);
if (!err)
vol->eba_tbl[lnum] = new_pnum;
out_put:
up_read(&ubi->fm_eba_sem);
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);
}
return err;
}
/** /**
* recover_peb - recover from write failure. * recover_peb - recover from write failure.
* @ubi: UBI device description object * @ubi: UBI device description object
@ -566,106 +662,34 @@ int ubi_eba_read_leb_sg(struct ubi_device *ubi, struct ubi_volume *vol,
* This function is called in case of a write failure and moves all good data * 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. * 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. * 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 * Returns 0 in case of success, and a negative error code in case of failure.
* 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, static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
const void *buf, int offset, int len) const void *buf, int offset, int len)
{ {
int err, idx = vol_id2idx(ubi, vol_id), new_pnum, data_size, tries = 0; int err, idx = vol_id2idx(ubi, vol_id), tries;
struct ubi_volume *vol = ubi->volumes[idx]; struct ubi_volume *vol = ubi->volumes[idx];
struct ubi_vid_hdr *vid_hdr; struct ubi_vid_hdr *vid_hdr;
uint32_t crc;
vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS); vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
if (!vid_hdr) if (!vid_hdr)
return -ENOMEM; return -ENOMEM;
retry: for (tries = 0; tries <= UBI_IO_RETRIES; tries++) {
new_pnum = ubi_wl_get_peb(ubi); bool retry;
if (new_pnum < 0) {
ubi_free_vid_hdr(ubi, vid_hdr); err = try_recover_peb(vol, pnum, lnum, buf, offset, len,
up_read(&ubi->fm_eba_sem); vid_hdr, &retry);
return new_pnum; if (!err || !retry)
break;
ubi_msg(ubi, "try again");
} }
ubi_msg(ubi, "recover PEB %d, move data to PEB %d",
pnum, new_pnum);
err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1);
if (err && err != UBI_IO_BITFLIPS) {
if (err > 0)
err = -EIO;
up_read(&ubi->fm_eba_sem);
goto out_put;
}
ubi_assert(vid_hdr->vol_type == UBI_VID_DYNAMIC);
mutex_lock(&ubi->buf_mutex);
memset(ubi->peb_buf + offset, 0xFF, len);
/* 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);
goto out_unlock;
}
}
memcpy(ubi->peb_buf + offset, buf, len);
data_size = offset + len;
crc = crc32(UBI_CRC32_INIT, ubi->peb_buf, data_size);
vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
vid_hdr->copy_flag = 1;
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;
}
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;
}
mutex_unlock(&ubi->buf_mutex);
ubi_free_vid_hdr(ubi, vid_hdr); ubi_free_vid_hdr(ubi, vid_hdr);
vol->eba_tbl[lnum] = new_pnum;
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;
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; 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;
}
ubi_msg(ubi, "try again");
goto retry;
} }
/** /**