| Message ID | 1402644381-24566-1-git-send-email-wen.gang.wang@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Looks good, thanks Wengang. Reviewed-by: Mark Fasheh <mfasheh@suse.de> --Mark On Fri, Jun 13, 2014 at 03:26:21PM +0800, Wengang Wang wrote: > Mark, please review. > > This patch tries to fix this crash: > > #5 [ffff88003c1cd690] do_invalid_op at ffffffff810166d5 > #6 [ffff88003c1cd730] invalid_op at ffffffff8159b2de > [exception RIP: ocfs2_direct_IO_get_blocks+359] > RIP: ffffffffa05dfa27 RSP: ffff88003c1cd7e8 RFLAGS: 00010202 > RAX: 0000000000000000 RBX: ffff88003c1cdaa8 RCX: 0000000000000000 > RDX: 000000000000000c RSI: ffff880027a95000 RDI: ffff88003c79b540 > RBP: ffff88003c1cd858 R8: 0000000000000000 R9: ffffffff815f6ba0 > R10: 00000000000001c9 R11: 00000000000001c9 R12: ffff88002d271500 > R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000001000 > ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 > #7 [ffff88003c1cd860] do_direct_IO at ffffffff811cd31b > #8 [ffff88003c1cd950] direct_IO_iovec at ffffffff811cde9c > #9 [ffff88003c1cd9b0] do_blockdev_direct_IO at ffffffff811ce764 > #10 [ffff88003c1cdb80] __blockdev_direct_IO at ffffffff811ce7cc > #11 [ffff88003c1cdbb0] ocfs2_direct_IO at ffffffffa05df756 [ocfs2] > #12 [ffff88003c1cdbe0] generic_file_direct_write_iter at ffffffff8112f935 > #13 [ffff88003c1cdc40] ocfs2_file_write_iter at ffffffffa0600ccc [ocfs2] > #14 [ffff88003c1cdd50] do_aio_write at ffffffff8119126c > #15 [ffff88003c1cddc0] aio_rw_vect_retry at ffffffff811d9bb4 > #16 [ffff88003c1cddf0] aio_run_iocb at ffffffff811db880 > #17 [ffff88003c1cde30] io_submit_one at ffffffff811dc238 > #18 [ffff88003c1cde80] do_io_submit at ffffffff811dc437 > #19 [ffff88003c1cdf70] sys_io_submit at ffffffff811dc530 > #20 [ffff88003c1cdf80] system_call_fastpath at ffffffff8159a159 > > It crashes at > BUG_ON(create && (ext_flags & OCFS2_EXT_REFCOUNTED)); > in ocfs2_direct_IO_get_blocks. > > ocfs2_direct_IO_get_blocks is expecting the OCFS2_EXT_REFCOUNTED be removed in > ocfs2_prepare_inode_for_write() if it was there. But no cluster lock is taken > during the time before (or inside) ocfs2_prepare_inode_for_write() and after > ocfs2_direct_IO_get_blocks(). > > It can happen in this case: > > Node A(which crashes) Node B > ------------------------ --------------------------- > ocfs2_file_aio_write > ocfs2_prepare_inode_for_write > ocfs2_inode_lock > ... > ocfs2_inode_unlock > #no refcount found > .... ocfs2_reflink > ocfs2_inode_lock > ... > ocfs2_inode_unlock > #now, refcount flag set on extent > > ... > flush change to disk > > ocfs2_direct_IO_get_blocks > ocfs2_get_clusters > #extent map miss > #buffer_head miss > read extents from disk > found refcount flag on extent > crash.. > > Fix: > Take rw_lock in ocfs2_reflink path > > Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com> > --- > fs/ocfs2/refcounttree.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c > index 6ba4bcb..2dddd9b 100644 > --- a/fs/ocfs2/refcounttree.c > +++ b/fs/ocfs2/refcounttree.c > @@ -4289,9 +4289,16 @@ static int ocfs2_reflink(struct dentry *old_dentry, struct inode *dir, > goto out; > } > > + error = ocfs2_rw_lock(inode, 1); > + if (error) { > + mlog_errno(error); > + goto out; > + } > + > error = ocfs2_inode_lock(inode, &old_bh, 1); > if (error) { > mlog_errno(error); > + ocfs2_rw_unlock(inode, 1); > goto out; > } > > @@ -4303,6 +4310,7 @@ static int ocfs2_reflink(struct dentry *old_dentry, struct inode *dir, > up_write(&OCFS2_I(inode)->ip_xattr_sem); > > ocfs2_inode_unlock(inode, 1); > + ocfs2_rw_unlock(inode, 1); > brelse(old_bh); > > if (error) { > -- > 1.8.3.1 > > > _______________________________________________ > Ocfs2-devel mailing list > Ocfs2-devel@oss.oracle.com > https://oss.oracle.com/mailman/listinfo/ocfs2-devel -- Mark Fasheh
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c index 6ba4bcb..2dddd9b 100644 --- a/fs/ocfs2/refcounttree.c +++ b/fs/ocfs2/refcounttree.c @@ -4289,9 +4289,16 @@ static int ocfs2_reflink(struct dentry *old_dentry, struct inode *dir, goto out; } + error = ocfs2_rw_lock(inode, 1); + if (error) { + mlog_errno(error); + goto out; + } + error = ocfs2_inode_lock(inode, &old_bh, 1); if (error) { mlog_errno(error); + ocfs2_rw_unlock(inode, 1); goto out; } @@ -4303,6 +4310,7 @@ static int ocfs2_reflink(struct dentry *old_dentry, struct inode *dir, up_write(&OCFS2_I(inode)->ip_xattr_sem); ocfs2_inode_unlock(inode, 1); + ocfs2_rw_unlock(inode, 1); brelse(old_bh); if (error) {
Mark, please review. This patch tries to fix this crash: #5 [ffff88003c1cd690] do_invalid_op at ffffffff810166d5 #6 [ffff88003c1cd730] invalid_op at ffffffff8159b2de [exception RIP: ocfs2_direct_IO_get_blocks+359] RIP: ffffffffa05dfa27 RSP: ffff88003c1cd7e8 RFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff88003c1cdaa8 RCX: 0000000000000000 RDX: 000000000000000c RSI: ffff880027a95000 RDI: ffff88003c79b540 RBP: ffff88003c1cd858 R8: 0000000000000000 R9: ffffffff815f6ba0 R10: 00000000000001c9 R11: 00000000000001c9 R12: ffff88002d271500 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000001000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffff88003c1cd860] do_direct_IO at ffffffff811cd31b #8 [ffff88003c1cd950] direct_IO_iovec at ffffffff811cde9c #9 [ffff88003c1cd9b0] do_blockdev_direct_IO at ffffffff811ce764 #10 [ffff88003c1cdb80] __blockdev_direct_IO at ffffffff811ce7cc #11 [ffff88003c1cdbb0] ocfs2_direct_IO at ffffffffa05df756 [ocfs2] #12 [ffff88003c1cdbe0] generic_file_direct_write_iter at ffffffff8112f935 #13 [ffff88003c1cdc40] ocfs2_file_write_iter at ffffffffa0600ccc [ocfs2] #14 [ffff88003c1cdd50] do_aio_write at ffffffff8119126c #15 [ffff88003c1cddc0] aio_rw_vect_retry at ffffffff811d9bb4 #16 [ffff88003c1cddf0] aio_run_iocb at ffffffff811db880 #17 [ffff88003c1cde30] io_submit_one at ffffffff811dc238 #18 [ffff88003c1cde80] do_io_submit at ffffffff811dc437 #19 [ffff88003c1cdf70] sys_io_submit at ffffffff811dc530 #20 [ffff88003c1cdf80] system_call_fastpath at ffffffff8159a159 It crashes at BUG_ON(create && (ext_flags & OCFS2_EXT_REFCOUNTED)); in ocfs2_direct_IO_get_blocks. ocfs2_direct_IO_get_blocks is expecting the OCFS2_EXT_REFCOUNTED be removed in ocfs2_prepare_inode_for_write() if it was there. But no cluster lock is taken during the time before (or inside) ocfs2_prepare_inode_for_write() and after ocfs2_direct_IO_get_blocks(). It can happen in this case: Node A(which crashes) Node B ------------------------ --------------------------- ocfs2_file_aio_write ocfs2_prepare_inode_for_write ocfs2_inode_lock ... ocfs2_inode_unlock #no refcount found .... ocfs2_reflink ocfs2_inode_lock ... ocfs2_inode_unlock #now, refcount flag set on extent ... flush change to disk ocfs2_direct_IO_get_blocks ocfs2_get_clusters #extent map miss #buffer_head miss read extents from disk found refcount flag on extent crash.. Fix: Take rw_lock in ocfs2_reflink path Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com> --- fs/ocfs2/refcounttree.c | 8 ++++++++ 1 file changed, 8 insertions(+)