@@ -949,10 +949,6 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
if (!ubi->peb_buf1)
goto out_free;
- ubi->peb_buf2 = vmalloc(ubi->peb_size);
- if (!ubi->peb_buf2)
- goto out_free;
-
err = ubi_debugging_init_dev(ubi);
if (err)
goto out_free;
@@ -1030,7 +1026,6 @@ out_debugging:
ubi_debugging_exit_dev(ubi);
out_free:
vfree(ubi->peb_buf1);
- vfree(ubi->peb_buf2);
if (ref)
put_device(&ubi->dev);
else
@@ -1102,7 +1097,6 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
put_mtd_device(ubi->mtd);
ubi_debugging_exit_dev(ubi);
vfree(ubi->peb_buf1);
- vfree(ubi->peb_buf2);
ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
put_device(&ubi->dev);
return 0;
@@ -985,9 +985,10 @@ static int is_error_sane(int err)
int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
struct ubi_vid_hdr *vid_hdr)
{
- int err, vol_id, lnum, data_size, aldata_size, idx;
+ int err, vol_id, lnum, data_size, aldata_size, idx, res;
struct ubi_volume *vol;
- uint32_t crc;
+ uint32_t crc, crc_read;
+ void *p, *peb_buf2;
vol_id = be32_to_cpu(vid_hdr->vol_id);
lnum = be32_to_cpu(vid_hdr->lnum);
@@ -1121,6 +1122,19 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
}
if (data_size > 0) {
+ /*
+ * We want that buffer to check we wrote the data correctly.
+ * If we can't allocate it, we will check the data we wrote
+ * using crc32.
+ */
+ peb_buf2 = vmalloc(ubi->peb_size);
+ if (!peb_buf2) {
+ dbg_wl("Can't allocate verification buffer, will work "
+ "in degraded mode");
+ p = ubi->peb_buf1;
+ } else
+ p = peb_buf2;
+
err = ubi_io_write_data(ubi, ubi->peb_buf1, to, 0, aldata_size);
if (err) {
if (err == -EIO)
@@ -1135,7 +1149,7 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
* sure it was written correctly.
*/
- err = ubi_io_read_data(ubi, ubi->peb_buf2, to, 0, aldata_size);
+ err = ubi_io_read_data(ubi, p, to, 0, aldata_size);
if (err) {
if (err != UBI_IO_BITFLIPS) {
ubi_warn("error %d while reading data back "
@@ -1149,7 +1163,14 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
cond_resched();
- if (memcmp(ubi->peb_buf1, ubi->peb_buf2, aldata_size)) {
+ if (peb_buf2) {
+ res = memcmp(ubi->peb_buf1, peb_buf2, aldata_size);
+ } else {
+ crc_read = crc32(UBI_CRC32_INIT, p, data_size);
+ res = (crc != crc_read);
+ }
+
+ if (res) {
ubi_warn("read data back from PEB %d and it is "
"different", to);
err = -EINVAL;
@@ -1164,6 +1185,8 @@ out_unlock_buf:
mutex_unlock(&ubi->buf_mutex);
out_unlock_leb:
leb_write_unlock(ubi, vol_id, lnum);
+ if (peb_buf2)
+ vfree(peb_buf2);
return err;
}
@@ -388,8 +388,7 @@ struct ubi_wl_entry;
* @mtd: MTD device descriptor
*
* @peb_buf1: a buffer of PEB size used for different purposes
- * @peb_buf2: another buffer of PEB size used for different purposes
- * @buf_mutex: protects @peb_buf1 and @peb_buf2
+ * @buf_mutex: protects @peb_buf1
* @ckvol_mutex: serializes static volume checking when opening
*
* @dbg: debugging information for this UBI device
@@ -472,7 +471,6 @@ struct ubi_device {
struct mtd_info *mtd;
void *peb_buf1;
- void *peb_buf2;
struct mutex buf_mutex;
struct mutex ckvol_mutex;
From: Josselin Costanzi <josselin.costanzi@mobile-devices.fr> Instead of using pre-allocated 'ubi->peb_buf2' buffer in 'ubi_eba_copy_leb()', dynamically allocate it when needed. The intent is to get rid of the pre-allocated 'ubi->peb_buf2' buffer and save up to 2MiB of RAM per attached device (or more if PEB size is larger). If the allocation fails, we fallback to a degraded mode where data integrity is still ensured, at the cost of higher CPU usage. --- drivers/mtd/ubi/build.c | 6 ------ drivers/mtd/ubi/eba.c | 31 +++++++++++++++++++++++++++---- drivers/mtd/ubi/ubi.h | 4 +--- 3 files changed, 28 insertions(+), 13 deletions(-)