The patch titled
mm: fix blkdev size calculation in generic_write_checks
has been added to the -mm tree. Its filename is
mm-fix-blkdev-size-calculation-in-generic_write_checks.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: mm: fix blkdev size calculation in generic_write_checks
From: Dmitry Monakhov <[EMAIL PROTECTED]>
Currently block device size calculated regardless its bd_block_size. This
may result attempt to write outside block device if i_size not aligned to
bdev->bd_block_size and result in EIO.
#### TEST_CASE_BEGIN
# fdisk -l /dev/sdc
Disk /dev/sdc: 36.7 GB, 36703918080 bytes
255 heads, 63 sectors/track, 4462 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdc1 * 1 254 2040223+ 83 Ldinux
/dev/sdc2 255 379 1004062+ 83 Linux
####
#### /dev/sdc2 size not aligned to 4K
#### at this time bd_block_size == 512 so generic_write_check
#### performed correctly
# dd if=/dev/zero of=/dev/sdc2 bs=1k count=7 seek=1004058
dd: writing `/dev/sdc2': No space left on device
5+0 records in
4+0 records out
#### this bdev contain ext4fs with blksize = 4K
# mount /dev/sdc2 /mnt/
#### after we mounted this bdev bd_block_size == fsblksize == 4K
#### the same write operation failed with EIO
# dd if=/dev/zero of=/dev/sdc2 bs=1k count=7 seek=1004058
dd: writing `/dev/sdc2': Input/output error
3+0 records in
2+0 records out
#### Attempt to write whole fsblock result write access outside
#### blkdevice and cause -EIO (returned by blkdev_get_block)
#### TEST_CASE_END
Signed-off-by: Dmitry Monakhov <[EMAIL PROTECTED]>
Cc: Al Viro <[EMAIL PROTECTED]>
Cc: Christoph Hellwig <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
---
mm/filemap.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff -puN mm/filemap.c~mm-fix-blkdev-size-calculation-in-generic_write_checks
mm/filemap.c
--- a/mm/filemap.c~mm-fix-blkdev-size-calculation-in-generic_write_checks
+++ a/mm/filemap.c
@@ -1856,9 +1856,11 @@ inline int generic_write_checks(struct f
} else {
#ifdef CONFIG_BLOCK
loff_t isize;
+ unsigned int blksize;
if (bdev_read_only(I_BDEV(inode)))
return -EPERM;
- isize = i_size_read(inode);
+ blksize = block_size(I_BDEV(inode));
+ isize = i_size_read(inode) & ~(blksize - 1);
if (*pos >= isize) {
if (*count || *pos > isize)
return -ENOSPC;
_
Patches currently in -mm which might be from [EMAIL PROTECTED] are
git-md-accel.patch
mm-fix-blkdev-size-calculation-in-generic_write_checks.patch
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