ext4: make the bitmap read routines return real error codes
Make the bitmap reaading routines return real error codes (EIO,
EFSCORRUPTED, EFSBADCRC) which can then be reflected back to
userspace for more precise diagnosis work.
In particular, this means that mballoc no longer claims that we're out
of memory if the block bitmaps become corrupt.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 32184c1..ec0668a 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -191,6 +191,7 @@
/* If checksum is bad mark all blocks used to prevent allocation
* essentially implementing a per-group read-only flag. */
if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
+ ext4_error(sb, "Checksum bad for group %u", block_group);
grp = ext4_get_group_info(sb, block_group);
if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
percpu_counter_sub(&sbi->s_freeclusters_counter,
@@ -360,19 +361,31 @@
return 0;
}
-static void ext4_validate_block_bitmap(struct super_block *sb,
- struct ext4_group_desc *desc,
- ext4_group_t block_group,
- struct buffer_head *bh)
+static int ext4_validate_block_bitmap(struct super_block *sb,
+ struct ext4_group_desc *desc,
+ ext4_group_t block_group,
+ struct buffer_head *bh)
{
ext4_fsblk_t blk;
struct ext4_group_info *grp = ext4_get_group_info(sb, block_group);
struct ext4_sb_info *sbi = EXT4_SB(sb);
- if (buffer_verified(bh) || EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
- return;
+ if (buffer_verified(bh))
+ return 0;
+ if (EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
+ return -EFSCORRUPTED;
ext4_lock_group(sb, block_group);
+ if (unlikely(!ext4_block_bitmap_csum_verify(sb, block_group,
+ desc, bh))) {
+ ext4_unlock_group(sb, block_group);
+ ext4_error(sb, "bg %u: bad block bitmap checksum", block_group);
+ if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
+ percpu_counter_sub(&sbi->s_freeclusters_counter,
+ grp->bb_free);
+ set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
+ return -EFSBADCRC;
+ }
blk = ext4_valid_block_bitmap(sb, desc, block_group, bh);
if (unlikely(blk != 0)) {
ext4_unlock_group(sb, block_group);
@@ -382,20 +395,11 @@
percpu_counter_sub(&sbi->s_freeclusters_counter,
grp->bb_free);
set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
- return;
- }
- if (unlikely(!ext4_block_bitmap_csum_verify(sb, block_group,
- desc, bh))) {
- ext4_unlock_group(sb, block_group);
- ext4_error(sb, "bg %u: bad block bitmap checksum", block_group);
- if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
- percpu_counter_sub(&sbi->s_freeclusters_counter,
- grp->bb_free);
- set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
- return;
+ return -EFSCORRUPTED;
}
set_buffer_verified(bh);
ext4_unlock_group(sb, block_group);
+ return 0;
}
/**
@@ -414,17 +418,18 @@
struct ext4_group_desc *desc;
struct buffer_head *bh;
ext4_fsblk_t bitmap_blk;
+ int err;
desc = ext4_get_group_desc(sb, block_group, NULL);
if (!desc)
- return NULL;
+ return ERR_PTR(-EFSCORRUPTED);
bitmap_blk = ext4_block_bitmap(sb, desc);
bh = sb_getblk(sb, bitmap_blk);
if (unlikely(!bh)) {
ext4_error(sb, "Cannot get buffer for block bitmap - "
"block_group = %u, block_bitmap = %llu",
block_group, bitmap_blk);
- return NULL;
+ return ERR_PTR(-ENOMEM);
}
if (bitmap_uptodate(bh))
@@ -437,7 +442,6 @@
}
ext4_lock_group(sb, block_group);
if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
- int err;
err = ext4_init_block_bitmap(sb, bh, block_group, desc);
set_bitmap_uptodate(bh);
@@ -445,7 +449,7 @@
ext4_unlock_group(sb, block_group);
unlock_buffer(bh);
if (err)
- ext4_error(sb, "Checksum bad for grp %u", block_group);
+ goto out;
goto verify;
}
ext4_unlock_group(sb, block_group);
@@ -468,11 +472,13 @@
submit_bh(READ | REQ_META | REQ_PRIO, bh);
return bh;
verify:
- ext4_validate_block_bitmap(sb, desc, block_group, bh);
- if (buffer_verified(bh))
- return bh;
+ err = ext4_validate_block_bitmap(sb, desc, block_group, bh);
+ if (err)
+ goto out;
+ return bh;
+out:
put_bh(bh);
- return NULL;
+ return ERR_PTR(err);
}
/* Returns 0 on success, 1 on error */
@@ -485,32 +491,32 @@
return 0;
desc = ext4_get_group_desc(sb, block_group, NULL);
if (!desc)
- return 1;
+ return -EFSCORRUPTED;
wait_on_buffer(bh);
if (!buffer_uptodate(bh)) {
ext4_error(sb, "Cannot read block bitmap - "
"block_group = %u, block_bitmap = %llu",
block_group, (unsigned long long) bh->b_blocknr);
- return 1;
+ return -EIO;
}
clear_buffer_new(bh);
/* Panic or remount fs read-only if block bitmap is invalid */
- ext4_validate_block_bitmap(sb, desc, block_group, bh);
- /* ...but check for error just in case errors=continue. */
- return !buffer_verified(bh);
+ return ext4_validate_block_bitmap(sb, desc, block_group, bh);
}
struct buffer_head *
ext4_read_block_bitmap(struct super_block *sb, ext4_group_t block_group)
{
struct buffer_head *bh;
+ int err;
bh = ext4_read_block_bitmap_nowait(sb, block_group);
- if (!bh)
- return NULL;
- if (ext4_wait_block_bitmap(sb, block_group, bh)) {
+ if (IS_ERR(bh))
+ return bh;
+ err = ext4_wait_block_bitmap(sb, block_group, bh);
+ if (err) {
put_bh(bh);
- return NULL;
+ return ERR_PTR(err);
}
return bh;
}
@@ -681,8 +687,10 @@
desc_count += ext4_free_group_clusters(sb, gdp);
brelse(bitmap_bh);
bitmap_bh = ext4_read_block_bitmap(sb, i);
- if (bitmap_bh == NULL)
+ if (IS_ERR(bitmap_bh)) {
+ bitmap_bh = NULL;
continue;
+ }
x = ext4_count_free(bitmap_bh->b_data,
EXT4_CLUSTERS_PER_GROUP(sb) / 8);
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 0d7f06e..1b8024d 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -64,7 +64,7 @@
}
/* Initializes an uninitialized inode bitmap */
-static unsigned ext4_init_inode_bitmap(struct super_block *sb,
+static int ext4_init_inode_bitmap(struct super_block *sb,
struct buffer_head *bh,
ext4_group_t block_group,
struct ext4_group_desc *gdp)
@@ -89,7 +89,7 @@
count);
}
set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
- return 0;
+ return -EFSBADCRC;
}
memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
@@ -99,7 +99,7 @@
EXT4_INODES_PER_GROUP(sb) / 8);
ext4_group_desc_csum_set(sb, block_group, gdp);
- return EXT4_INODES_PER_GROUP(sb);
+ return 0;
}
void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
@@ -112,6 +112,42 @@
put_bh(bh);
}
+static int ext4_validate_inode_bitmap(struct super_block *sb,
+ struct ext4_group_desc *desc,
+ ext4_group_t block_group,
+ struct buffer_head *bh)
+{
+ ext4_fsblk_t blk;
+ struct ext4_group_info *grp = ext4_get_group_info(sb, block_group);
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+ if (buffer_verified(bh))
+ return 0;
+ if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
+ return -EFSCORRUPTED;
+
+ ext4_lock_group(sb, block_group);
+ blk = ext4_inode_bitmap(sb, desc);
+ if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
+ EXT4_INODES_PER_GROUP(sb) / 8)) {
+ ext4_unlock_group(sb, block_group);
+ ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
+ "inode_bitmap = %llu", block_group, blk);
+ grp = ext4_get_group_info(sb, block_group);
+ if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
+ int count;
+ count = ext4_free_inodes_count(sb, desc);
+ percpu_counter_sub(&sbi->s_freeinodes_counter,
+ count);
+ }
+ set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
+ return -EFSBADCRC;
+ }
+ set_buffer_verified(bh);
+ ext4_unlock_group(sb, block_group);
+ return 0;
+}
+
/*
* Read the inode allocation bitmap for a given block_group, reading
* into the specified slot in the superblock's bitmap cache.
@@ -124,12 +160,11 @@
struct ext4_group_desc *desc;
struct buffer_head *bh = NULL;
ext4_fsblk_t bitmap_blk;
- struct ext4_group_info *grp;
- struct ext4_sb_info *sbi = EXT4_SB(sb);
+ int err;
desc = ext4_get_group_desc(sb, block_group, NULL);
if (!desc)
- return NULL;
+ return ERR_PTR(-EFSCORRUPTED);
bitmap_blk = ext4_inode_bitmap(sb, desc);
bh = sb_getblk(sb, bitmap_blk);
@@ -137,7 +172,7 @@
ext4_error(sb, "Cannot read inode bitmap - "
"block_group = %u, inode_bitmap = %llu",
block_group, bitmap_blk);
- return NULL;
+ return ERR_PTR(-EIO);
}
if (bitmap_uptodate(bh))
goto verify;
@@ -150,12 +185,14 @@
ext4_lock_group(sb, block_group);
if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
- ext4_init_inode_bitmap(sb, bh, block_group, desc);
+ err = ext4_init_inode_bitmap(sb, bh, block_group, desc);
set_bitmap_uptodate(bh);
set_buffer_uptodate(bh);
set_buffer_verified(bh);
ext4_unlock_group(sb, block_group);
unlock_buffer(bh);
+ if (err)
+ goto out;
return bh;
}
ext4_unlock_group(sb, block_group);
@@ -182,31 +219,17 @@
ext4_error(sb, "Cannot read inode bitmap - "
"block_group = %u, inode_bitmap = %llu",
block_group, bitmap_blk);
- return NULL;
+ return ERR_PTR(-EIO);
}
verify:
- ext4_lock_group(sb, block_group);
- if (!buffer_verified(bh) &&
- !ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
- EXT4_INODES_PER_GROUP(sb) / 8)) {
- ext4_unlock_group(sb, block_group);
- put_bh(bh);
- ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
- "inode_bitmap = %llu", block_group, bitmap_blk);
- grp = ext4_get_group_info(sb, block_group);
- if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
- int count;
- count = ext4_free_inodes_count(sb, desc);
- percpu_counter_sub(&sbi->s_freeinodes_counter,
- count);
- }
- set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
- return NULL;
- }
- ext4_unlock_group(sb, block_group);
- set_buffer_verified(bh);
+ err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
+ if (err)
+ goto out;
return bh;
+out:
+ put_bh(bh);
+ return ERR_PTR(err);
}
/*
@@ -286,8 +309,15 @@
bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
/* Don't bother if the inode bitmap is corrupt. */
grp = ext4_get_group_info(sb, block_group);
- if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) || !bitmap_bh)
+ if (IS_ERR(bitmap_bh)) {
+ fatal = PTR_ERR(bitmap_bh);
+ bitmap_bh = NULL;
goto error_return;
+ }
+ if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {
+ fatal = -EFSCORRUPTED;
+ goto error_return;
+ }
BUFFER_TRACE(bitmap_bh, "get_write_access");
fatal = ext4_journal_get_write_access(handle, bitmap_bh);
@@ -826,7 +856,9 @@
brelse(inode_bitmap_bh);
inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
/* Skip groups with suspicious inode tables */
- if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) || !inode_bitmap_bh) {
+ if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) ||
+ IS_ERR(inode_bitmap_bh)) {
+ inode_bitmap_bh = NULL;
if (++group == ngroups)
group = 0;
continue;
@@ -902,8 +934,8 @@
struct buffer_head *block_bitmap_bh;
block_bitmap_bh = ext4_read_block_bitmap(sb, group);
- if (!block_bitmap_bh) {
- err = -EIO;
+ if (IS_ERR(block_bitmap_bh)) {
+ err = PTR_ERR(block_bitmap_bh);
goto out;
}
BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
@@ -1123,8 +1155,10 @@
block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
- if (!bitmap_bh) {
- ext4_warning(sb, "inode bitmap error for orphan %lu", ino);
+ if (IS_ERR(bitmap_bh)) {
+ err = PTR_ERR(bitmap_bh);
+ ext4_warning(sb, "inode bitmap error %ld for orphan %lu",
+ ino, err);
goto error;
}
@@ -1199,8 +1233,10 @@
desc_count += ext4_free_inodes_count(sb, gdp);
brelse(bitmap_bh);
bitmap_bh = ext4_read_inode_bitmap(sb, i);
- if (!bitmap_bh)
+ if (IS_ERR(bitmap_bh)) {
+ bitmap_bh = NULL;
continue;
+ }
x = ext4_count_free(bitmap_bh->b_data,
EXT4_INODES_PER_GROUP(sb) / 8);
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index b0f7ee5..6794ff4 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -874,8 +874,10 @@
bh[i] = NULL;
continue;
}
- if (!(bh[i] = ext4_read_block_bitmap_nowait(sb, group))) {
- err = -ENOMEM;
+ bh[i] = ext4_read_block_bitmap_nowait(sb, group);
+ if (IS_ERR(bh[i])) {
+ err = PTR_ERR(bh[i]);
+ bh[i] = NULL;
goto out;
}
mb_debug(1, "read bitmap for group %u\n", group);
@@ -883,8 +885,13 @@
/* wait for I/O completion */
for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
- if (bh[i] && ext4_wait_block_bitmap(sb, group, bh[i]))
- err = -EIO;
+ int err2;
+
+ if (!bh[i])
+ continue;
+ err2 = ext4_wait_block_bitmap(sb, group, bh[i]);
+ if (!err)
+ err = err2;
}
first_block = page->index * blocks_per_page;
@@ -2447,7 +2454,7 @@
kmalloc(sb->s_blocksize, GFP_NOFS);
BUG_ON(meta_group_info[i]->bb_bitmap == NULL);
bh = ext4_read_block_bitmap(sb, group);
- BUG_ON(bh == NULL);
+ BUG_ON(IS_ERR_OR_NULL(bh));
memcpy(meta_group_info[i]->bb_bitmap, bh->b_data,
sb->s_blocksize);
put_bh(bh);
@@ -2889,10 +2896,12 @@
sb = ac->ac_sb;
sbi = EXT4_SB(sb);
- err = -EIO;
bitmap_bh = ext4_read_block_bitmap(sb, ac->ac_b_ex.fe_group);
- if (!bitmap_bh)
+ if (IS_ERR(bitmap_bh)) {
+ err = PTR_ERR(bitmap_bh);
+ bitmap_bh = NULL;
goto out_err;
+ }
BUFFER_TRACE(bitmap_bh, "getting write access");
err = ext4_journal_get_write_access(handle, bitmap_bh);
@@ -3836,8 +3845,10 @@
return 0;
bitmap_bh = ext4_read_block_bitmap(sb, group);
- if (bitmap_bh == NULL) {
- ext4_error(sb, "Error reading block bitmap for %u", group);
+ if (IS_ERR(bitmap_bh)) {
+ err = PTR_ERR(bitmap_bh);
+ ext4_error(sb, "Error %d reading block bitmap for %u",
+ err, group);
return 0;
}
@@ -4008,9 +4019,10 @@
}
bitmap_bh = ext4_read_block_bitmap(sb, group);
- if (bitmap_bh == NULL) {
- ext4_error(sb, "Error reading block bitmap for %u",
- group);
+ if (IS_ERR(bitmap_bh)) {
+ err = PTR_ERR(bitmap_bh);
+ ext4_error(sb, "Error %d reading block bitmap for %u",
+ err, group);
ext4_mb_unload_buddy(&e4b);
continue;
}
@@ -4754,8 +4766,9 @@
}
count_clusters = EXT4_NUM_B2C(sbi, count);
bitmap_bh = ext4_read_block_bitmap(sb, block_group);
- if (!bitmap_bh) {
- err = -EIO;
+ if (IS_ERR(bitmap_bh)) {
+ err = PTR_ERR(bitmap_bh);
+ bitmap_bh = NULL;
goto error_return;
}
gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
@@ -4924,8 +4937,9 @@
}
bitmap_bh = ext4_read_block_bitmap(sb, block_group);
- if (!bitmap_bh) {
- err = -EIO;
+ if (IS_ERR(bitmap_bh)) {
+ err = PTR_ERR(bitmap_bh);
+ bitmap_bh = NULL;
goto error_return;
}