ocfs2: fix oops when writing cloned file
commit2d797e9ff9
upstream. Writing a cloned file triggers a kernel oops and the user-space command process is also killed by the system. The bug can be reproduced stably via: 1) create a file under ocfs2 file system directory. journalctl -b > aa.txt 2) create a cloned file for this file. reflink aa.txt bb.txt 3) write the cloned file with dd command. dd if=/dev/zero of=bb.txt bs=512 count=1 conv=notrunc The dd command is killed by the kernel, then you can see the oops message via dmesg command. [ 463.875404] BUG: kernel NULL pointer dereference, address: 0000000000000028 [ 463.875413] #PF: supervisor read access in kernel mode [ 463.875416] #PF: error_code(0x0000) - not-present page [ 463.875418] PGD 0 P4D 0 [ 463.875425] Oops: 0000 [#1] SMP PTI [ 463.875431] CPU: 1 PID: 2291 Comm: dd Tainted: G OE 5.3.16-2-default [ 463.875433] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [ 463.875500] RIP: 0010:ocfs2_refcount_cow+0xa4/0x5d0 [ocfs2] [ 463.875505] Code: 06 89 6c 24 38 89 eb f6 44 24 3c 02 74 be 49 8b 47 28 [ 463.875508] RSP: 0018:ffffa2cb409dfce8 EFLAGS: 00010202 [ 463.875512] RAX: ffff8b1ebdca8000 RBX: 0000000000000001 RCX: ffff8b1eb73a9df0 [ 463.875515] RDX: 0000000000056a01 RSI: 0000000000000000 RDI: 0000000000000000 [ 463.875517] RBP: 0000000000000001 R08: ffff8b1eb73a9de0 R09: 0000000000000000 [ 463.875520] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 [ 463.875522] R13: ffff8b1eb922f048 R14: 0000000000000000 R15: ffff8b1eb922f048 [ 463.875526] FS: 00007f8f44d15540(0000) GS:ffff8b1ebeb00000(0000) knlGS:0000000000000000 [ 463.875529] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 463.875532] CR2: 0000000000000028 CR3: 000000003c17a000 CR4: 00000000000006e0 [ 463.875546] Call Trace: [ 463.875596] ? ocfs2_inode_lock_full_nested+0x18b/0x960 [ocfs2] [ 463.875648] ocfs2_file_write_iter+0xaf8/0xc70 [ocfs2] [ 463.875672] new_sync_write+0x12d/0x1d0 [ 463.875688] vfs_write+0xad/0x1a0 [ 463.875697] ksys_write+0xa1/0xe0 [ 463.875710] do_syscall_64+0x60/0x1f0 [ 463.875743] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 463.875758] RIP: 0033:0x7f8f4482ed44 [ 463.875762] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 80 00 00 00 [ 463.875765] RSP: 002b:00007fff300a79d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 463.875769] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8f4482ed44 [ 463.875771] RDX: 0000000000000200 RSI: 000055f771b5c000 RDI: 0000000000000001 [ 463.875774] RBP: 0000000000000200 R08: 00007f8f44af9c78 R09: 0000000000000003 [ 463.875776] R10: 000000000000089f R11: 0000000000000246 R12: 000055f771b5c000 [ 463.875779] R13: 0000000000000200 R14: 0000000000000000 R15: 000055f771b5c000 This regression problem was introduced by commite74540b285
("ocfs2: protect extent tree in ocfs2_prepare_inode_for_write()"). Link: http://lkml.kernel.org/r/20200121050153.13290-1-ghe@suse.com Fixes:e74540b285
("ocfs2: protect extent tree in ocfs2_prepare_inode_for_write()"). Signed-off-by: Gang He <ghe@suse.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Jun Piao <piaojun@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
6e41b54999
commit
03c03090c3
|
@ -2101,17 +2101,15 @@ static int ocfs2_is_io_unaligned(struct inode *inode, size_t count, loff_t pos)
|
|||
static int ocfs2_inode_lock_for_extent_tree(struct inode *inode,
|
||||
struct buffer_head **di_bh,
|
||||
int meta_level,
|
||||
int overwrite_io,
|
||||
int write_sem,
|
||||
int wait)
|
||||
{
|
||||
int ret = 0;
|
||||
|
||||
if (wait)
|
||||
ret = ocfs2_inode_lock(inode, NULL, meta_level);
|
||||
ret = ocfs2_inode_lock(inode, di_bh, meta_level);
|
||||
else
|
||||
ret = ocfs2_try_inode_lock(inode,
|
||||
overwrite_io ? NULL : di_bh, meta_level);
|
||||
ret = ocfs2_try_inode_lock(inode, di_bh, meta_level);
|
||||
if (ret < 0)
|
||||
goto out;
|
||||
|
||||
|
@ -2136,6 +2134,7 @@ static int ocfs2_inode_lock_for_extent_tree(struct inode *inode,
|
|||
|
||||
out_unlock:
|
||||
brelse(*di_bh);
|
||||
*di_bh = NULL;
|
||||
ocfs2_inode_unlock(inode, meta_level);
|
||||
out:
|
||||
return ret;
|
||||
|
@ -2177,7 +2176,6 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
|
|||
ret = ocfs2_inode_lock_for_extent_tree(inode,
|
||||
&di_bh,
|
||||
meta_level,
|
||||
overwrite_io,
|
||||
write_sem,
|
||||
wait);
|
||||
if (ret < 0) {
|
||||
|
@ -2233,13 +2231,13 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
|
|||
&di_bh,
|
||||
meta_level,
|
||||
write_sem);
|
||||
meta_level = 1;
|
||||
write_sem = 1;
|
||||
ret = ocfs2_inode_lock_for_extent_tree(inode,
|
||||
&di_bh,
|
||||
meta_level,
|
||||
overwrite_io,
|
||||
1,
|
||||
write_sem,
|
||||
wait);
|
||||
write_sem = 1;
|
||||
if (ret < 0) {
|
||||
if (ret != -EAGAIN)
|
||||
mlog_errno(ret);
|
||||
|
|
Loading…
Reference in New Issue