From 087ffd4eae9929afd06f6a709861df3c3508492a Mon Sep 17 00:00:00 2001 From: Junxiao Bi Date: Fri, 4 Dec 2015 12:29:28 -0500 Subject: [PATCH] jbd2: fix null committed data return in undo_access introduced jbd2_write_access_granted() to improve write|undo_access speed, but missed to check the status of b_committed_data which caused a kernel panic on ocfs2. [ 6538.405938] ------------[ cut here ]------------ [ 6538.406686] kernel BUG at fs/ocfs2/suballoc.c:2400! [ 6538.406686] invalid opcode: 0000 [#1] SMP [ 6538.406686] Modules linked in: ocfs2 nfsd lockd grace nfs_acl auth_rpcgss sunrpc autofs4 ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue configfs sd_mod sg ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i libcxgbi cxgb3 mdio ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr ipv6 iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ppdev xen_kbdfront xen_netfront xen_fbfront parport_pc parport pcspkr i2c_piix4 acpi_cpufreq ext4 jbd2 mbcache xen_blkfront floppy pata_acpi ata_generic ata_piix cirrus ttm drm_kms_helper drm fb_sys_fops sysimgblt sysfillrect i2c_core syscopyarea dm_mirror dm_region_hash dm_log dm_mod [ 6538.406686] CPU: 1 PID: 16265 Comm: mmap_truncate Not tainted 4.3.0 #1 [ 6538.406686] Hardware name: Xen HVM domU, BIOS 4.3.1OVM 05/14/2014 [ 6538.406686] task: ffff88007c2bab00 ti: ffff880075b78000 task.ti: ffff880075b78000 [ 6538.406686] RIP: 0010:[] [] ocfs2_block_group_clear_bits+0x23b/0x250 [ocfs2] [ 6538.406686] RSP: 0018:ffff880075b7b7f8 EFLAGS: 00010246 [ 6538.406686] RAX: ffff8800760c5b40 RBX: ffff88006c06a000 RCX: ffffffffa06e6df0 [ 6538.406686] RDX: 0000000000000000 RSI: ffff88007a6f6ea0 RDI: ffff88007a760430 [ 6538.406686] RBP: ffff880075b7b878 R08: 0000000000000002 R09: 0000000000000001 [ 6538.406686] R10: ffffffffa06769be R11: 0000000000000000 R12: 0000000000000001 [ 6538.406686] R13: ffffffffa06a1750 R14: 0000000000000001 R15: ffff88007a6f6ea0 [ 6538.406686] FS: 00007f17fde30720(0000) GS:ffff88007f040000(0000) knlGS:0000000000000000 [ 6538.406686] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6538.406686] CR2: 0000000000601730 CR3: 000000007aea0000 CR4: 00000000000406e0 [ 6538.406686] Stack: [ 6538.406686] ffff88007c2bb5b0 ffff880075b7b8e0 ffff88007a7604b0 ffff88006c640800 [ 6538.406686] ffff88007a7604b0 ffff880075d77390 0000000075b7b878 ffffffffa06a309d [ 6538.406686] ffff880075d752d8 ffff880075b7b990 ffff880075b7b898 0000000000000000 [ 6538.406686] Call Trace: [ 6538.406686] [] ? ocfs2_read_group_descriptor+0x6d/0xa0 [ocfs2] [ 6538.406686] [] _ocfs2_free_suballoc_bits+0xe4/0x320 [ocfs2] [ 6538.406686] [] ? ocfs2_put_slot+0xf0/0xf0 [ocfs2] [ 6538.406686] [] _ocfs2_free_clusters+0xee/0x210 [ocfs2] [ 6538.406686] [] ? ocfs2_put_slot+0xf0/0xf0 [ocfs2] [ 6538.406686] [] ? ocfs2_put_slot+0xf0/0xf0 [ocfs2] [ 6538.406686] [] ? ocfs2_extend_trans+0x50/0x1a0 [ocfs2] [ 6538.406686] [] ocfs2_free_clusters+0x15/0x20 [ocfs2] [ 6538.406686] [] ocfs2_replay_truncate_records+0xfc/0x290 [ocfs2] [ 6538.406686] [] ? ocfs2_start_trans+0xec/0x1d0 [ocfs2] [ 6538.406686] [] __ocfs2_flush_truncate_log+0x140/0x2d0 [ocfs2] [ 6538.406686] [] ? ocfs2_reserve_blocks_for_rec_trunc.clone.0+0x44/0x170 [ocfs2] [ 6538.406686] [] ocfs2_remove_btree_range+0x374/0x630 [ocfs2] [ 6538.406686] [] ? jbd2_journal_stop+0x25b/0x470 [jbd2] [ 6538.406686] [] ocfs2_commit_truncate+0x305/0x670 [ocfs2] [ 6538.406686] [] ? ocfs2_journal_access_eb+0x20/0x20 [ocfs2] [ 6538.406686] [] ocfs2_truncate_file+0x297/0x380 [ocfs2] [ 6538.406686] [] ? jbd2_journal_begin_ordered_truncate+0x64/0xc0 [jbd2] [ 6538.406686] [] ocfs2_setattr+0x572/0x860 [ocfs2] [ 6538.406686] [] ? current_fs_time+0x3f/0x50 [ 6538.406686] [] notify_change+0x1d7/0x340 [ 6538.406686] [] ? generic_getxattr+0x79/0x80 [ 6538.406686] [] do_truncate+0x66/0x90 [ 6538.406686] [] ? __audit_syscall_entry+0xb0/0x110 [ 6538.406686] [] do_sys_ftruncate.clone.0+0xf3/0x120 [ 6538.406686] [] SyS_ftruncate+0xe/0x10 [ 6538.406686] [] entry_SYSCALL_64_fastpath+0x12/0x71 [ 6538.406686] Code: 28 48 81 ee b0 04 00 00 48 8b 92 50 fb ff ff 48 8b 80 b0 03 00 00 48 39 90 88 00 00 00 0f 84 30 fe ff ff 0f 0b eb fe 0f 0b eb fe <0f> 0b 0f 1f 00 eb fb 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 [ 6538.406686] RIP [] ocfs2_block_group_clear_bits+0x23b/0x250 [ocfs2] [ 6538.406686] RSP [ 6538.691128] ---[ end trace 31cd7011d6770d7e ]--- [ 6538.694492] Kernel panic - not syncing: Fatal exception [ 6538.695484] Kernel Offset: disabled Fixes: de92c8caf16c("jbd2: speedup jbd2_journal_get_[write|undo]_access()") Cc: Signed-off-by: Junxiao Bi Signed-off-by: Theodore Ts'o --- fs/jbd2/transaction.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index b99621277c66..1498ad9f731a 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -1009,7 +1009,8 @@ do_get_write_access(handle_t *handle, struct journal_head *jh, } /* Fast check whether buffer is already attached to the required transaction */ -static bool jbd2_write_access_granted(handle_t *handle, struct buffer_head *bh) +static bool jbd2_write_access_granted(handle_t *handle, struct buffer_head *bh, + bool undo) { struct journal_head *jh; bool ret = false; @@ -1036,6 +1037,9 @@ static bool jbd2_write_access_granted(handle_t *handle, struct buffer_head *bh) jh = READ_ONCE(bh->b_private); if (!jh) goto out; + /* For undo access buffer must have data copied */ + if (undo && !jh->b_committed_data) + goto out; if (jh->b_transaction != handle->h_transaction && jh->b_next_transaction != handle->h_transaction) goto out; @@ -1073,7 +1077,7 @@ int jbd2_journal_get_write_access(handle_t *handle, struct buffer_head *bh) struct journal_head *jh; int rc; - if (jbd2_write_access_granted(handle, bh)) + if (jbd2_write_access_granted(handle, bh, false)) return 0; jh = jbd2_journal_add_journal_head(bh); @@ -1210,7 +1214,7 @@ int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh) char *committed_data = NULL; JBUFFER_TRACE(jh, "entry"); - if (jbd2_write_access_granted(handle, bh)) + if (jbd2_write_access_granted(handle, bh, true)) return 0; jh = jbd2_journal_add_journal_head(bh); -- GitLab