If ext2fs_new_block2() is called without a specific block map, we
should call the alloc_block hook before checking fs->block_map. This
helps us to avoid a bug in e2fsck where we need to allocate a block
but instead of consulting block_found_map, we use the FS bitmaps,
which (prior to pass 5) could be wrong.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
e2fsck/pass1.c | 2 +-
lib/ext2fs/alloc.c | 15 +++++++++++++++
2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
index af64fd1..4cc58c4 100644
--- a/e2fsck/pass1.c
+++ b/e2fsck/pass1.c
@@ -3728,7 +3728,7 @@ static errcode_t e2fsck_get_alloc_block(ext2_filsys fs, blk64_t goal,
return retval;
}
- retval = ext2fs_new_block2(fs, goal, 0, &new_block);
+ retval = ext2fs_new_block2(fs, goal, fs->block_map, &new_block);
if (retval)
return retval;
}
diff --git a/lib/ext2fs/alloc.c b/lib/ext2fs/alloc.c
index fda45f9..d3c8e50 100644
--- a/lib/ext2fs/alloc.c
+++ b/lib/ext2fs/alloc.c
@@ -137,9 +137,23 @@ errcode_t ext2fs_new_block2(ext2_filsys fs, blk64_t goal,
{
errcode_t retval;
blk64_t b = 0;
+ errcode_t (*gab)(ext2_filsys fs, blk64_t goal, blk64_t *ret);
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+ if (!map && fs->get_alloc_block) {
+ /*
+ * In case there are clients out there whose get_alloc_block
+ * handlers call ext2fs_new_block2 with a NULL block map,
+ * temporarily swap out the function pointer so that we don't
+ * end up in an infinite loop.
+ */
+ gab = fs->get_alloc_block;
+ fs->get_alloc_block = NULL;
+ retval = gab(fs, goal, &b);
+ fs->get_alloc_block = gab;
+ goto allocated;
+ }
if (!map)
map = fs->block_map;
if (!map)
@@ -153,6 +167,7 @@ errcode_t ext2fs_new_block2(ext2_filsys fs, blk64_t goal,
if ((retval == ENOENT) && (goal != fs->super->s_first_data_block))
retval = ext2fs_find_first_zero_block_bitmap2(map,
fs->super->s_first_data_block, goal - 1, &b);
+allocated:
if (retval == ENOENT)
return EXT2_ET_BLOCK_ALLOC_FAIL;
if (retval)
--
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