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When heavily exercising xattr code the assertion that jbd2_journal_dirty_metadata() shouldn't return error was triggered: WARNING: at /srv/autobuild-ceph/gitbuilder.git/build/fs/jbd2/transaction.c:1237 jbd2_journal_dirty_metadata+0x1ba/0x260() CPU: 0 PID: 8877 Comm: ceph-osd Tainted: G W 3.10.0-ceph-00049-g68d04c9 #1 Hardware name: Dell Inc. PowerEdge R410/01V648, BIOS 1.6.3 02/07/2011 ffffffff81a1d3c8 ffff880214469928 ffffffff816311b0 ffff880214469968 ffffffff8103fae0 ffff880214469958 ffff880170a9dc30 ffff8802240fbe80 0000000000000000 ffff88020b366000 ffff8802256e7510 ffff880214469978 Call Trace: [<ffffffff816311b0>] dump_stack+0x19/0x1b [<ffffffff8103fae0>] warn_slowpath_common+0x70/0xa0 [<ffffffff8103fb2a>] warn_slowpath_null+0x1a/0x20 [<ffffffff81267c2a>] jbd2_journal_dirty_metadata+0x1ba/0x260 [<ffffffff81245093>] __ext4_handle_dirty_metadata+0xa3/0x140 [<ffffffff812561f3>] ext4_xattr_release_block+0x103/0x1f0 [<ffffffff81256680>] ext4_xattr_block_set+0x1e0/0x910 [<ffffffff8125795b>] ext4_xattr_set_handle+0x38b/0x4a0 [<ffffffff810a319d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff81257b32>] ext4_xattr_set+0xc2/0x140 [<ffffffff81258547>] ext4_xattr_user_set+0x47/0x50 [<ffffffff811935ce>] generic_setxattr+0x6e/0x90 [<ffffffff81193ecb>] __vfs_setxattr_noperm+0x7b/0x1c0 [<ffffffff811940d4>] vfs_setxattr+0xc4/0xd0 [<ffffffff8119421e>] setxattr+0x13e/0x1e0 [<ffffffff811719c7>] ? __sb_start_write+0xe7/0x1b0 [<ffffffff8118f2e8>] ? mnt_want_write_file+0x28/0x60 [<ffffffff8118c65c>] ? fget_light+0x3c/0x130 [<ffffffff8118f2e8>] ? mnt_want_write_file+0x28/0x60 [<ffffffff8118f1f8>] ? __mnt_want_write+0x58/0x70 [<ffffffff811946be>] SyS_fsetxattr+0xbe/0x100 [<ffffffff816407c2>] system_call_fastpath+0x16/0x1b The reason for the warning is that buffer_head passed into jbd2_journal_dirty_metadata() didn't have journal_head attached. This is caused by the following race of two ext4_xattr_release_block() calls: CPU1 CPU2 ext4_xattr_release_block() ext4_xattr_release_block() lock_buffer(bh); /* False */ if (BHDR(bh)->h_refcount == cpu_to_le32(1)) } else { le32_add_cpu(&BHDR(bh)->h_refcount, -1); unlock_buffer(bh); lock_buffer(bh); /* True */ if (BHDR(bh)->h_refcount == cpu_to_le32(1)) get_bh(bh); ext4_free_blocks() ... jbd2_journal_forget() jbd2_journal_unfile_buffer() -> JH is gone error = ext4_handle_dirty_xattr_block(handle, inode, bh); -> triggers the warning We fix the problem by moving ext4_handle_dirty_xattr_block() under the buffer lock. Sadly this cannot be done in nojournal mode as that function can call sync_dirty_buffer() which would deadlock. Luckily in nojournal mode the race is harmless (we only dirty already freed buffer) and thus for nojournal mode we leave the dirtying outside of the buffer lock. Reported-by: Sage Weil <sage@inktank.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@vger.kernel.org |
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| .. | ||
| acl.c | ||
| acl.h | ||
| balloc.c | ||
| bitmap.c | ||
| block_validity.c | ||
| dir.c | ||
| ext4_extents.h | ||
| ext4_jbd2.c | ||
| ext4_jbd2.h | ||
| ext4.h | ||
| extents_status.c | ||
| extents_status.h | ||
| extents.c | ||
| file.c | ||
| fsync.c | ||
| hash.c | ||
| ialloc.c | ||
| indirect.c | ||
| inline.c | ||
| inode.c | ||
| ioctl.c | ||
| Kconfig | ||
| Makefile | ||
| mballoc.c | ||
| mballoc.h | ||
| migrate.c | ||
| mmp.c | ||
| move_extent.c | ||
| namei.c | ||
| page-io.c | ||
| resize.c | ||
| super.c | ||
| symlink.c | ||
| truncate.h | ||
| xattr_security.c | ||
| xattr_trusted.c | ||
| xattr_user.c | ||
| xattr.c | ||
| xattr.h | ||