linux_dsm_epyc7002/fs
Dmitry Monakhov 357b66fdc8 ext4: ext4_split_extent should take care of extent zeroout
When ext4_split_extent_at() ends up doing zeroout & conversion to
initialized instead of split & conversion, ext4_split_extent() gets
confused and can wrongly mark the extent back as uninitialized
resulting in end IO code getting confused from large unwritten extents
and may result in data loss.

The example of problematic behavior is:
			    lblk len              lblk len
  ext4_split_extent() (ex=[1000,30,uninit], map=[1010,10])
    ext4_split_extent_at() (split [1000,30,uninit] at 1020)
      ext4_ext_insert_extent() -> ENOSPC
      ext4_ext_zeroout()
	 -> extent [1000,30] is now initialized
    ext4_split_extent_at() (split [1000,30,init] at 1010,
			     MARK_UNINIT1 | MARK_UNINIT2)
      -> extent is split and parts marked as uninitialized

Fix the problem by rechecking extent type after the first
ext4_split_extent_at() returns. None of split_flags can not be applied
to initialized extent so this patch also add BUG_ON to prevent similar
issues in future.

TESTCASE: b8a55eb5ce

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2013-03-04 00:34:34 -05:00
..
9p
adfs
affs
afs
autofs4
befs
bfs
btrfs
cachefiles
ceph
cifs
coda
configfs
cramfs
debugfs
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ext4 ext4: ext4_split_extent should take care of extent zeroout 2013-03-04 00:34:34 -05:00
f2fs
fat
freevxfs
fscache
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gfs2
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jbd2 jbd2: fix ERR_PTR dereference in jbd2__journal_start 2013-03-02 17:08:46 -05:00
jffs2
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nfs nfs: avoid dereferencing null pointer in initiate_bulk_draining 2013-01-05 14:26:51 -05:00
nfs_common
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aio.c
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
binfmt_som.c
bio-integrity.c
bio.c
block_dev.c
buffer.c
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c
compat.c
coredump.c
coredump.h
dcache.c
dcookies.c
direct-io.c
drop_caches.c
eventfd.c
eventpoll.c
exec.c
fcntl.c
fhandle.c
fifo.c
file_table.c
file.c
filesystems.c
fs_struct.c
fs-writeback.c
generic_acl.c
inode.c
internal.h
ioctl.c
ioprio.c
Kconfig
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libfs.c
locks.c
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mount.h
mpage.c
namei.c
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no-block.c
open.c
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pnode.c
pnode.h
posix_acl.c
proc_namespace.c
read_write.c
read_write.h
readdir.c
select.c
seq_file.c
signalfd.c
splice.c tcp: fix MSG_SENDPAGE_NOTLAST logic 2013-01-06 20:58:13 -08:00
stack.c
stat.c
statfs.c
super.c
sync.c
timerfd.c
utimes.c
xattr_acl.c
xattr.c