Read in a full block for each allocation bitmap, to avoid using a
kernel bounce buffer when using direct I/O.
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
---
lib/ext2fs/rw_bitmaps.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/lib/ext2fs/rw_bitmaps.c b/lib/ext2fs/rw_bitmaps.c
index 1d5f7b2..81e09c0 100644
--- a/lib/ext2fs/rw_bitmaps.c
+++ b/lib/ext2fs/rw_bitmaps.c
@@ -166,6 +166,9 @@ static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+ if ((block_nbytes > fs->blocksize) || (inode_nbytes > fs->blocksize))
+ return EXT2_ET_CORRUPT_SUPERBLOCK;
+
fs->write_bitmaps = ext2fs_write_bitmaps;
if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
@@ -186,7 +189,7 @@ static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
if (do_image)
retval = ext2fs_get_mem(fs->blocksize, &block_bitmap);
else
- retval = ext2fs_get_memalign((unsigned) block_nbytes,
+ retval = ext2fs_get_memalign(fs->blocksize,
fs->blocksize,
&block_bitmap);
@@ -202,8 +205,7 @@ static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
if (retval)
goto cleanup;
- retval = ext2fs_get_mem(do_image ? fs->blocksize :
- (unsigned) inode_nbytes, &inode_bitmap);
+ retval = ext2fs_get_mem(fs->blocksize, &inode_bitmap);
if (retval)
goto cleanup;
} else
@@ -261,7 +263,7 @@ static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
blk = 0;
if (blk) {
retval = io_channel_read_blk64(fs->io, blk,
- -block_nbytes, block_bitmap);
+ 1, block_bitmap);
if (retval) {
retval = EXT2_ET_BLOCK_BITMAP_READ;
goto cleanup;
@@ -283,7 +285,7 @@ static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
blk = 0;
if (blk) {
retval = io_channel_read_blk64(fs->io, blk,
- -inode_nbytes, inode_bitmap);
+ 1, inode_bitmap);
if (retval) {
retval = EXT2_ET_INODE_BITMAP_READ;
goto cleanup;
--
1.7.10.rc3
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