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UBI: do not use vmalloc on I/O path
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Similar reason as in case of the previous patch: it causes
deadlocks if a filesystem with writeback support works on top
of UBI. So pre-allocate needed buffers when attaching MTD device.
We also need mutexes to protect the buffers, but they do not
cause much contantion because they are used in recovery, torture,
and WL copy routines, which are called seldom.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
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Artem Bityutskiy authored and Artem Bityutskiy committed Oct 14, 2007
1 parent 33818bb commit e88d6e1
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Showing 8 changed files with 119 additions and 112 deletions.
28 changes: 27 additions & 1 deletion drivers/mtd/ubi/build.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -565,7 +565,7 @@ static int attach_mtd_dev(const char *mtd_dev, int vid_hdr_offset,
}

ubi = ubi_devices[ubi_devices_cnt] = kzalloc(sizeof(struct ubi_device),
GFP_KERNEL);
GFP_KERNEL);
if (!ubi) {
err = -ENOMEM;
goto out_mtd;
Expand All @@ -583,6 +583,22 @@ static int attach_mtd_dev(const char *mtd_dev, int vid_hdr_offset,
if (err)
goto out_free;

mutex_init(&ubi->buf_mutex);
ubi->peb_buf1 = vmalloc(ubi->peb_size);
if (!ubi->peb_buf1)
goto out_free;

ubi->peb_buf2 = vmalloc(ubi->peb_size);
if (!ubi->peb_buf2)
goto out_free;

#ifdef CONFIG_MTD_UBI_DEBUG
mutex_init(&ubi->dbg_buf_mutex);
ubi->dbg_peb_buf = vmalloc(ubi->peb_size);
if (!ubi->dbg_peb_buf)
goto out_free;
#endif

err = attach_by_scanning(ubi);
if (err) {
dbg_err("failed to attach by scanning, error %d", err);
Expand Down Expand Up @@ -630,6 +646,11 @@ static int attach_mtd_dev(const char *mtd_dev, int vid_hdr_offset,
ubi_wl_close(ubi);
vfree(ubi->vtbl);
out_free:
vfree(ubi->peb_buf1);
vfree(ubi->peb_buf2);
#ifdef CONFIG_MTD_UBI_DEBUG
vfree(ubi->dbg_peb_buf);
#endif
kfree(ubi);
out_mtd:
put_mtd_device(mtd);
Expand All @@ -651,6 +672,11 @@ static void detach_mtd_dev(struct ubi_device *ubi)
ubi_wl_close(ubi);
vfree(ubi->vtbl);
put_mtd_device(ubi->mtd);
vfree(ubi->peb_buf1);
vfree(ubi->peb_buf2);
#ifdef CONFIG_MTD_UBI_DEBUG
vfree(ubi->dbg_peb_buf);
#endif
kfree(ubi_devices[ubi_num]);
ubi_devices[ubi_num] = NULL;
ubi_devices_cnt -= 1;
Expand Down
70 changes: 24 additions & 46 deletions drivers/mtd/ubi/eba.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -495,16 +495,18 @@ static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
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;
unsigned char *new_buf;

vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
if (!vid_hdr) {
return -ENOMEM;
}

mutex_lock(&ubi->buf_mutex);

retry:
new_pnum = ubi_wl_get_peb(ubi, UBI_UNKNOWN);
if (new_pnum < 0) {
mutex_unlock(&ubi->buf_mutex);
ubi_free_vid_hdr(ubi, vid_hdr);
return new_pnum;
}
Expand All @@ -524,31 +526,22 @@ static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
goto write_error;

data_size = offset + len;
new_buf = vmalloc(data_size);
if (!new_buf) {
err = -ENOMEM;
goto out_put;
}
memset(new_buf + offset, 0xFF, len);
memset(ubi->peb_buf1 + offset, 0xFF, len);

/* Read everything before the area where the write failure happened */
if (offset > 0) {
err = ubi_io_read_data(ubi, new_buf, pnum, 0, offset);
if (err && err != UBI_IO_BITFLIPS) {
vfree(new_buf);
err = ubi_io_read_data(ubi, ubi->peb_buf1, pnum, 0, offset);
if (err && err != UBI_IO_BITFLIPS)
goto out_put;
}
}

memcpy(new_buf + offset, buf, len);
memcpy(ubi->peb_buf1 + offset, buf, len);

err = ubi_io_write_data(ubi, new_buf, new_pnum, 0, data_size);
if (err) {
vfree(new_buf);
err = ubi_io_write_data(ubi, ubi->peb_buf1, new_pnum, 0, data_size);
if (err)
goto write_error;
}

vfree(new_buf);
mutex_unlock(&ubi->buf_mutex);
ubi_free_vid_hdr(ubi, vid_hdr);

vol->eba_tbl[lnum] = new_pnum;
Expand All @@ -558,6 +551,7 @@ static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
return 0;

out_put:
mutex_unlock(&ubi->buf_mutex);
ubi_wl_put_peb(ubi, new_pnum, 1);
ubi_free_vid_hdr(ubi, vid_hdr);
return err;
Expand All @@ -570,6 +564,7 @@ static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
ubi_warn("failed to write to PEB %d", new_pnum);
ubi_wl_put_peb(ubi, new_pnum, 1);
if (++tries > UBI_IO_RETRIES) {
mutex_unlock(&ubi->buf_mutex);
ubi_free_vid_hdr(ubi, vid_hdr);
return err;
}
Expand Down Expand Up @@ -965,7 +960,6 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
int err, vol_id, lnum, data_size, aldata_size, pnum, idx;
struct ubi_volume *vol;
uint32_t crc;
void *buf, *buf1 = NULL;

vol_id = be32_to_cpu(vid_hdr->vol_id);
lnum = be32_to_cpu(vid_hdr->lnum);
Expand All @@ -979,19 +973,15 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
data_size = aldata_size =
ubi->leb_size - be32_to_cpu(vid_hdr->data_pad);

buf = vmalloc(aldata_size);
if (!buf)
return -ENOMEM;

/*
* We do not want anybody to write to this logical eraseblock while we
* are moving it, so we lock it.
*/
err = leb_write_lock(ubi, vol_id, lnum);
if (err) {
vfree(buf);
if (err)
return err;
}

mutex_lock(&ubi->buf_mutex);

/*
* But the logical eraseblock might have been put by this time.
Expand Down Expand Up @@ -1023,7 +1013,7 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
/* OK, now the LEB is locked and we can safely start moving it */

dbg_eba("read %d bytes of data", aldata_size);
err = ubi_io_read_data(ubi, buf, from, 0, aldata_size);
err = ubi_io_read_data(ubi, ubi->peb_buf1, from, 0, aldata_size);
if (err && err != UBI_IO_BITFLIPS) {
ubi_warn("error %d while reading data from PEB %d",
err, from);
Expand All @@ -1042,10 +1032,10 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
*/
if (vid_hdr->vol_type == UBI_VID_DYNAMIC)
aldata_size = data_size =
ubi_calc_data_len(ubi, buf, data_size);
ubi_calc_data_len(ubi, ubi->peb_buf1, data_size);

cond_resched();
crc = crc32(UBI_CRC32_INIT, buf, data_size);
crc = crc32(UBI_CRC32_INIT, ubi->peb_buf1, data_size);
cond_resched();

/*
Expand Down Expand Up @@ -1076,23 +1066,18 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
}

if (data_size > 0) {
err = ubi_io_write_data(ubi, buf, to, 0, aldata_size);
err = ubi_io_write_data(ubi, ubi->peb_buf1, to, 0, aldata_size);
if (err)
goto out_unlock;

cond_resched();

/*
* We've written the data and are going to read it back to make
* sure it was written correctly.
*/
buf1 = vmalloc(aldata_size);
if (!buf1) {
err = -ENOMEM;
goto out_unlock;
}

cond_resched();

err = ubi_io_read_data(ubi, buf1, to, 0, aldata_size);
err = ubi_io_read_data(ubi, ubi->peb_buf2, to, 0, aldata_size);
if (err) {
if (err != UBI_IO_BITFLIPS)
ubi_warn("cannot read data back from PEB %d",
Expand All @@ -1102,7 +1087,7 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,

cond_resched();

if (memcmp(buf, buf1, aldata_size)) {
if (memcmp(ubi->peb_buf1, ubi->peb_buf2, aldata_size)) {
ubi_warn("read data back from PEB %d - it is different",
to);
goto out_unlock;
Expand All @@ -1112,16 +1097,9 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
ubi_assert(vol->eba_tbl[lnum] == from);
vol->eba_tbl[lnum] = to;

leb_write_unlock(ubi, vol_id, lnum);
vfree(buf);
vfree(buf1);

return 0;

out_unlock:
mutex_unlock(&ubi->buf_mutex);
leb_write_unlock(ubi, vol_id, lnum);
vfree(buf);
vfree(buf1);
return err;
}

Expand Down
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