From: Dmitry Monakhov <dmonakhov@openvz.org>
To: linux-ext4@vger.kernel.org
Cc: tytso@mit.edu, jack@suse.cz, lczerner@redhat.com,
Dmitry Monakhov <dmonakhov@openvz.org>
Subject: [PATCH 03/10] ext4: fix unwritten counter leakage
Date: Mon, 24 Sep 2012 15:44:13 +0400 [thread overview]
Message-ID: <1348487060-19598-4-git-send-email-dmonakhov@openvz.org> (raw)
In-Reply-To: <1348487060-19598-1-git-send-email-dmonakhov@openvz.org>
ext4_set_io_unwritten_flag() will increment i_unwritten counter, so
once we mark end_io with END_IO_UNWRITTEN we have to revert it back
on error path.
- add missed error checks to prevent counter leakage
- ext4_end_io_nolock() will clear END_IO_UNWRITTEN flag to signal
that conversion finished.
- add BUGON to free_end_io() to prevent similar leackage in future.
Visiable effect of this bug is that unaligned aio_stress may deadlock
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
---
fs/ext4/extents.c | 21 ++++++++++++++-------
fs/ext4/page-io.c | 6 +++++-
2 files changed, 19 insertions(+), 8 deletions(-)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 6eb6b0c..739c21d 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3660,6 +3660,8 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
ret = ext4_split_unwritten_extents(handle, inode, map,
path, flags);
+ if (ret <= 0)
+ goto out;
/*
* Flag the inode(non aio case) or end_io struct (aio case)
* that this IO needs to conversion to written when IO is
@@ -3905,6 +3907,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
struct ext4_allocation_request ar;
ext4_io_end_t *io = (ext4_io_end_t*) EXT4_CUR_AIO_DIO(inode);
ext4_lblk_t cluster_offset;
+ int set_unwritten = 0;
ext_debug("blocks %u/%u requested for inode %lu\n",
map->m_lblk, map->m_len, inode->i_ino);
@@ -4127,13 +4130,8 @@ got_allocated_blocks:
* For non asycn direct IO case, flag the inode state
* that we need to perform conversion when IO is done.
*/
- if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
- if (io)
- ext4_set_io_unwritten_flag(inode, io);
- else
- ext4_set_inode_state(inode,
- EXT4_STATE_DIO_UNWRITTEN);
- }
+ if ((flags & EXT4_GET_BLOCKS_PRE_IO))
+ set_unwritten = 1;
if (ext4_should_dioread_nolock(inode))
map->m_flags |= EXT4_MAP_UNINIT;
}
@@ -4145,6 +4143,15 @@ got_allocated_blocks:
if (!err)
err = ext4_ext_insert_extent(handle, inode, path,
&newex, flags);
+
+ if (!err && set_unwritten) {
+ if (io)
+ ext4_set_io_unwritten_flag(inode, io);
+ else
+ ext4_set_inode_state(inode,
+ EXT4_STATE_DIO_UNWRITTEN);
+ }
+
if (err && free_on_err) {
int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index de77e31..9970022 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -71,6 +71,8 @@ void ext4_free_io_end(ext4_io_end_t *io)
int i;
BUG_ON(!io);
+ BUG_ON(io->flag & EXT4_IO_END_UNWRITTEN);
+
if (io->page)
put_page(io->page);
for (i = 0; i < io->num_io_pages; i++)
@@ -94,6 +96,8 @@ int ext4_end_io_nolock(ext4_io_end_t *io)
ssize_t size = io->size;
int ret = 0;
+ BUG_ON(!(io->flag & EXT4_IO_END_UNWRITTEN));
+
ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p,"
"list->prev 0x%p\n",
io, inode->i_ino, io->list.next, io->list.prev);
@@ -106,7 +110,7 @@ int ext4_end_io_nolock(ext4_io_end_t *io)
"(inode %lu, offset %llu, size %zd, error %d)",
inode->i_ino, offset, size, ret);
}
next prev parent reply other threads:[~2012-09-24 11:44 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-24 11:44 [PATCH 00/10] ext4: Bunch of DIO/AIO fixes V3 Dmitry Monakhov
2012-09-24 11:44 ` [PATCH 01/10] ext4: ext4_inode_info diet Dmitry Monakhov
2012-09-26 12:28 ` Jan Kara
2012-09-24 11:44 ` [PATCH 02/10] ext4: give i_aiodio_unwritten more appropriate name Dmitry Monakhov
2012-09-26 12:32 ` Jan Kara
2012-09-24 11:44 ` Dmitry Monakhov [this message]
2012-09-26 13:07 ` [PATCH 03/10] ext4: fix unwritten counter leakage Jan Kara
2012-09-27 12:19 ` Dmitry Monakhov
2012-09-27 12:34 ` Jan Kara
2012-09-27 12:54 ` Dmitry Monakhov
2012-09-27 13:07 ` Jan Kara
2012-09-24 11:44 ` [PATCH 04/10] ext4: completed_io locking cleanup V3 Dmitry Monakhov
2012-09-26 13:42 ` Jan Kara
2012-09-27 11:24 ` Dmitry Monakhov
2012-09-24 11:44 ` [PATCH 05/10] ext4: serialize dio nonlocked reads with defrag workers V3 Dmitry Monakhov
2012-09-26 13:49 ` Jan Kara
2012-09-24 11:44 ` [PATCH 06/10] ext4: punch_hole should wait for DIO writers V2 Dmitry Monakhov
2012-09-26 13:56 ` Jan Kara
2012-09-24 11:44 ` [PATCH 07/10] ext4: serialize unlocked dio reads with truncate Dmitry Monakhov
2012-09-24 11:44 ` [PATCH 08/10] ext4: endless truncate due to nonlocked dio readers V2 Dmitry Monakhov
2012-09-26 14:05 ` Jan Kara
2012-09-27 15:11 ` Dmitry Monakhov
2012-09-27 15:23 ` Jan Kara
2012-09-24 11:44 ` [PATCH 09/10] ext4: serialize truncate with owerwrite DIO workers V2 Dmitry Monakhov
2012-09-24 11:44 ` [PATCH 10/10] ext4: fix ext_remove_space for punch_hole case Dmitry Monakhov
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