[PATCH] Btrfs: do not release delalloc space until after we end the transaction
There have been many sporadic reports of the following panic [ cut here ] kernel BUG at fs/btrfs/extent-tree.c:5498! invalid opcode: [#1] PREEMPT SMP last sysfs file: /sys/devices/system/cpu/cpu7/cache/index2/shared_cpu_map CPU 7 Modules linked in: btrfs zlib_deflate libcrc32c netconsole configfs ipt_MASQUERADE iptable_nat nf_nat bridge stp llc sunrpc cpufreq_ondemand acpi_cpufreq freq_table mperf xt_physdev ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables ipv6 dm_multipath kvm uinput snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd hp_wmi i5400_edac sparse_keymap iTCO_wdt rfkill edac_core tg3 shpchp iTCO_vendor_support soundcore wmi floppy snd_page_alloc pcspkr i5k_amb [last unloaded: btrfs] Pid: 28504, comm: btrfs-endio-wri Tainted: GW 2.6.39-rc2+ #35 Hewlett-Packard HP xw6600 Workstation/0A9Ch RIP: 0010:[] [] alloc_reserved_file_extent+0x9a/0x1e5 [btrfs] RSP: 0018:88000b4319f0 EFLAGS: 00010286 RAX: ffe4 RBX: 880009fdc438 RCX: 880020c216d0 RDX: 88000b4318c0 RSI: 00d5 RDI: RBP: 88000b431a70 R08: ffe4 R09: 880020c216d0 R10: 0001 R11: 88000b431b10 R12: 88000b431b10 R13: 00b2 R14: R15: 88002225f2f8 FS: () GS:88003e40() knlGS: CS: 0010 DS: ES: CR0: 8005003b CR2: 003738ca6940 CR3: 2a39a000 CR4: 06e0 DR0: DR1: DR2: DR3: DR6: 0ff0 DR7: 0400 Process btrfs-endio-wri (pid: 28504, threadinfo 88000b43, task 880032278000) Stack: 0001 88002a92 881d 038d 0005 88003aa38000 81481012 88000c3bb480 8800241d01c8 88000b431a60 880031a040a8 Call Trace: [] ? sub_preempt_count+0x97/0xaa [] run_clustered_refs+0x61b/0x700 [btrfs] [] ? sub_preempt_count+0xe/0xaa [] ? spin_lock+0xe/0x10 [btrfs] [] btrfs_run_delayed_refs+0xd1/0x1ab [btrfs] [] ? _raw_spin_unlock+0x4a/0x57 [] __btrfs_end_transaction+0x89/0x1ed [btrfs] [] btrfs_end_transaction+0x15/0x17 [btrfs] [] btrfs_finish_ordered_io+0x29c/0x2bf [btrfs] [] btrfs_writepage_end_io_hook+0x81/0x8d [btrfs] [] end_bio_extent_writepage+0xae/0x159 [btrfs] [] bio_endio+0x2d/0x2f [] end_workqueue_fn+0x111/0x120 [btrfs] [] worker_loop+0x192/0x4d1 [btrfs] [] ? btrfs_queue_worker+0x22c/0x22c [btrfs] [] kthread+0xa0/0xa8 [] ? trace_hardirqs_on_caller+0x111/0x135 [] kernel_thread_helper+0x4/0x10 [] ? retint_restore_args+0x13/0x13 [] ? __init_kthread_worker+0x5b/0x5b [] ? gs_change+0x13/0x13 Code: 44 8b 45 90 0f 84 58 01 00 00 80 88 88 00 00 00 08 41 83 c0 18 4c 89 e1 48 8b 72 20 4c 89 ff 48 89 c2 e8 1f b4 ff ff 85 c0 74 04 <0f> 0b eb fe 48 8b 03 48 89 45 c8 8b 73 40 48 89 c7 e8 bc 98 ff RIP [] alloc_reserved_file_extent+0x9a/0x1e5 [btrfs] RSP ---[ end trace 81d1c68cb00af83e ]--- This is because we have been releasing the delalloc bytes before ending the transaction. However the way we make allocations, any updates to the extent_tree are delayed and then run when the transaction runs, so we still have plenty of space that we need to use. So instead release the delalloc bytes _after_ we end the transaction so that we don't get this false ENOSPC. Thanks, Signed-off-by: Josef Bacik --- fs/btrfs/inode.c |8 ++-- 1 files changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index ade00e7..b1e5b11 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1783,9 +1783,13 @@ out: if (trans) btrfs_end_transaction_nolock(trans, root); } else { - btrfs_delalloc_release_metadata(inode, ordered_extent->len); if (trans) btrfs_end_transaction(trans, root); + /* +* Release after the transaction ends so it covers the delayed +* ref updates +*/ + btrfs_delalloc_release_metadata(inode, ordered_extent->len); } /* once for us */ @@ -5897,8 +5901,8 @@ out_unlock: ordered->file_offset + ordered->len - 1, &cached_state, GFP_NOFS); out: - btrfs_delalloc_release_metadata(inode, ordered->len); btrfs_end_transaction(trans, root); + btrfs_delalloc_release_metadata(inode, ordered->len); ordered_offset = ordered->file_offset + ordered->len; btrfs_put_ordered_extent(ordered); btrfs_put_ordered_extent(ordered); -- 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.ht
Re: [PATCH] Btrfs: do not release delalloc space until after we end the transaction
On 13.04.2011 20:54, Josef Bacik wrote: There have been many sporadic reports of the following panic [ cut here ] kernel BUG at fs/btrfs/extent-tree.c:5498! invalid opcode: [#1] PREEMPT SMP last sysfs file: /sys/devices/system/cpu/cpu7/cache/index2/shared_cpu_map CPU 7 Modules linked in: btrfs zlib_deflate libcrc32c netconsole configfs ipt_MASQUERADE iptable_nat nf_nat bridge stp llc sunrpc cpufreq_ondemand acpi_cpufreq freq_table mperf xt_physdev ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables ipv6 dm_multipath kvm uinput snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd hp_wmi i5400_edac sparse_keymap iTCO_wdt rfkill edac_core tg3 shpchp iTCO_vendor_support soundcore wmi floppy snd_page_alloc pcspkr i5k_amb [last unloaded: btrfs] Pid: 28504, comm: btrfs-endio-wri Tainted: GW 2.6.39-rc2+ #35 Hewlett-Packard HP xw6600 Workstation/0A9Ch RIP: 0010:[] [] alloc_reserved_file_extent+0x9a/0x1e5 [btrfs] RSP: 0018:88000b4319f0 EFLAGS: 00010286 RAX: ffe4 RBX: 880009fdc438 RCX: 880020c216d0 RDX: 88000b4318c0 RSI: 00d5 RDI: RBP: 88000b431a70 R08: ffe4 R09: 880020c216d0 R10: 0001 R11: 88000b431b10 R12: 88000b431b10 R13: 00b2 R14: R15: 88002225f2f8 FS: () GS:88003e40() knlGS: CS: 0010 DS: ES: CR0: 8005003b CR2: 003738ca6940 CR3: 2a39a000 CR4: 06e0 DR0: DR1: DR2: DR3: DR6: 0ff0 DR7: 0400 Process btrfs-endio-wri (pid: 28504, threadinfo 88000b43, task 880032278000) Stack: 0001 88002a92 881d 038d 0005 88003aa38000 81481012 88000c3bb480 8800241d01c8 88000b431a60 880031a040a8 Call Trace: [] ? sub_preempt_count+0x97/0xaa [] run_clustered_refs+0x61b/0x700 [btrfs] [] ? sub_preempt_count+0xe/0xaa [] ? spin_lock+0xe/0x10 [btrfs] [] btrfs_run_delayed_refs+0xd1/0x1ab [btrfs] [] ? _raw_spin_unlock+0x4a/0x57 [] __btrfs_end_transaction+0x89/0x1ed [btrfs] [] btrfs_end_transaction+0x15/0x17 [btrfs] [] btrfs_finish_ordered_io+0x29c/0x2bf [btrfs] [] btrfs_writepage_end_io_hook+0x81/0x8d [btrfs] [] end_bio_extent_writepage+0xae/0x159 [btrfs] [] bio_endio+0x2d/0x2f [] end_workqueue_fn+0x111/0x120 [btrfs] [] worker_loop+0x192/0x4d1 [btrfs] [] ? btrfs_queue_worker+0x22c/0x22c [btrfs] [] kthread+0xa0/0xa8 [] ? trace_hardirqs_on_caller+0x111/0x135 [] kernel_thread_helper+0x4/0x10 [] ? retint_restore_args+0x13/0x13 [] ? __init_kthread_worker+0x5b/0x5b [] ? gs_change+0x13/0x13 Code: 44 8b 45 90 0f 84 58 01 00 00 80 88 88 00 00 00 08 41 83 c0 18 4c 89 e1 48 8b 72 20 4c 89 ff 48 89 c2 e8 1f b4 ff ff 85 c0 74 04<0f> 0b eb fe 48 8b 03 48 89 45 c8 8b 73 40 48 89 c7 e8 bc 98 ff RIP [] alloc_reserved_file_extent+0x9a/0x1e5 [btrfs] RSP ---[ end trace 81d1c68cb00af83e ]--- This is because we have been releasing the delalloc bytes before ending the transaction. However the way we make allocations, any updates to the extent_tree are delayed and then run when the transaction runs, so we still have plenty of space that we need to use. So instead release the delalloc bytes _after_ we end the transaction so that we don't get this false ENOSPC. Thanks, Signed-off-by: Josef Bacik --- fs/btrfs/inode.c |8 ++-- 1 files changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index ade00e7..b1e5b11 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1783,9 +1783,13 @@ out: if (trans) btrfs_end_transaction_nolock(trans, root); } else { - btrfs_delalloc_release_metadata(inode, ordered_extent->len); if (trans) btrfs_end_transaction(trans, root); + /* +* Release after the transaction ends so it covers the delayed +* ref updates +*/ + btrfs_delalloc_release_metadata(inode, ordered_extent->len); I think calling end_transaction doesn't guarantee you that all delayed refs have run, only if end_transaction leads to commit transaction. Another problem I see is that commit_transaction just uses the block_rsv of whatever trans happened to call commit, even if the trans->block_rsv have been set to a different block_rsv than trans_block_rsv or delalloc_block_rsv. In other words, the relayed_refs are run from a non- deterministic block_rsv. But it's late, I'll think more about it tomorrow. -Arne } /* once for us */ @@ -5897,8 +5901,8 @@ out_unlock: ordered->file_offset + ordered->len - 1,
Re: [PATCH] Btrfs: do not release delalloc space until after we end the transaction
On Thu, Apr 14, 2011 at 2:54 AM, Josef Bacik wrote: > There have been many sporadic reports of the following panic > > [ cut here ] > kernel BUG at fs/btrfs/extent-tree.c:5498! > invalid opcode: [#1] PREEMPT SMP > last sysfs file: /sys/devices/system/cpu/cpu7/cache/index2/shared_cpu_map > CPU 7 > Modules linked in: btrfs zlib_deflate libcrc32c netconsole configfs > ipt_MASQUERADE iptable_nat nf_nat bridge stp llc sunrpc cpufreq_ondemand > acpi_cpufreq freq_table mperf xt_physdev ip6t_REJECT nf_conntrack_ipv6 > nf_defrag_ipv6 ip6table_filter ip6_tables ipv6 dm_multipath kvm uinput > snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq > snd_seq_device snd_pcm snd_timer snd hp_wmi i5400_edac sparse_keymap iTCO_wdt > rfkill edac_core tg3 shpchp iTCO_vendor_support soundcore wmi floppy > snd_page_alloc pcspkr i5k_amb [last unloaded: btrfs] > > Pid: 28504, comm: btrfs-endio-wri Tainted: G W 2.6.39-rc2+ #35 > Hewlett-Packard HP xw6600 Workstation/0A9Ch > RIP: 0010:[] [] > alloc_reserved_file_extent+0x9a/0x1e5 [btrfs] > RSP: 0018:88000b4319f0 EFLAGS: 00010286 > RAX: ffe4 RBX: 880009fdc438 RCX: 880020c216d0 > RDX: 88000b4318c0 RSI: 00d5 RDI: > RBP: 88000b431a70 R08: ffe4 R09: 880020c216d0 > R10: 0001 R11: 88000b431b10 R12: 88000b431b10 > R13: 00b2 R14: R15: 88002225f2f8 > FS: () GS:88003e40() knlGS: > CS: 0010 DS: ES: CR0: 8005003b > CR2: 003738ca6940 CR3: 2a39a000 CR4: 06e0 > DR0: DR1: DR2: > DR3: DR6: 0ff0 DR7: 0400 > Process btrfs-endio-wri (pid: 28504, threadinfo 88000b43, task > 880032278000) > Stack: > 0001 88002a92 881d 038d > 0005 88003aa38000 81481012 > 88000c3bb480 8800241d01c8 88000b431a60 880031a040a8 > Call Trace: > [] ? sub_preempt_count+0x97/0xaa > [] run_clustered_refs+0x61b/0x700 [btrfs] > [] ? sub_preempt_count+0xe/0xaa > [] ? spin_lock+0xe/0x10 [btrfs] > [] btrfs_run_delayed_refs+0xd1/0x1ab [btrfs] > [] ? _raw_spin_unlock+0x4a/0x57 > [] __btrfs_end_transaction+0x89/0x1ed [btrfs] > [] btrfs_end_transaction+0x15/0x17 [btrfs] > [] btrfs_finish_ordered_io+0x29c/0x2bf [btrfs] > [] btrfs_writepage_end_io_hook+0x81/0x8d [btrfs] > [] end_bio_extent_writepage+0xae/0x159 [btrfs] > [] bio_endio+0x2d/0x2f > [] end_workqueue_fn+0x111/0x120 [btrfs] > [] worker_loop+0x192/0x4d1 [btrfs] > [] ? btrfs_queue_worker+0x22c/0x22c [btrfs] > [] kthread+0xa0/0xa8 > [] ? trace_hardirqs_on_caller+0x111/0x135 > [] kernel_thread_helper+0x4/0x10 > [] ? retint_restore_args+0x13/0x13 > [] ? __init_kthread_worker+0x5b/0x5b > [] ? gs_change+0x13/0x13 > Code: 44 8b 45 90 0f 84 58 01 00 00 80 88 88 00 00 00 08 41 83 c0 18 4c 89 e1 > 48 8b 72 20 4c 89 ff 48 89 c2 e8 1f b4 ff ff 85 c0 74 04 <0f> 0b eb fe 48 8b > 03 48 89 45 c8 8b 73 40 48 89 c7 e8 bc 98 ff > RIP [] alloc_reserved_file_extent+0x9a/0x1e5 [btrfs] > RSP > ---[ end trace 81d1c68cb00af83e ]--- > > This is because we have been releasing the delalloc bytes before ending the > transaction. However the way we make allocations, any updates to the > extent_tree are delayed and then run when the transaction runs, so we still > have > plenty of space that we need to use. So instead release the delalloc bytes > _after_ we end the transaction so that we don't get this false ENOSPC. > Thanks, > This is wrong, because btrfs_run_delayed_refs uses global block reservation. > Signed-off-by: Josef Bacik > --- > fs/btrfs/inode.c | 8 ++-- > 1 files changed, 6 insertions(+), 2 deletions(-) > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index ade00e7..b1e5b11 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -1783,9 +1783,13 @@ out: > if (trans) > btrfs_end_transaction_nolock(trans, root); > } else { > - btrfs_delalloc_release_metadata(inode, ordered_extent->len); > if (trans) > btrfs_end_transaction(trans, root); > + /* > + * Release after the transaction ends so it covers the delayed > + * ref updates > + */ > + btrfs_delalloc_release_metadata(inode, ordered_extent->len); > } > > /* once for us */ > @@ -5897,8 +5901,8 @@ out_unlock: > ordered->file_offset + ordered->len - 1, > &cached_state, GFP_NOFS); > out: > - btrfs_delalloc_release_metadata(inode, ordered->len); > btrfs_end_transaction(trans, root); > + btrfs_delalloc_release_metadata(inode, ordered->len); > ordered_offset =
Re: [PATCH] Btrfs: do not release delalloc space until after we end the transaction
On 04/13/2011 06:08 PM, Arne Jansen wrote: On 13.04.2011 20:54, Josef Bacik wrote: There have been many sporadic reports of the following panic [ cut here ] kernel BUG at fs/btrfs/extent-tree.c:5498! invalid opcode: [#1] PREEMPT SMP last sysfs file: /sys/devices/system/cpu/cpu7/cache/index2/shared_cpu_map CPU 7 Modules linked in: btrfs zlib_deflate libcrc32c netconsole configfs ipt_MASQUERADE iptable_nat nf_nat bridge stp llc sunrpc cpufreq_ondemand acpi_cpufreq freq_table mperf xt_physdev ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables ipv6 dm_multipath kvm uinput snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd hp_wmi i5400_edac sparse_keymap iTCO_wdt rfkill edac_core tg3 shpchp iTCO_vendor_support soundcore wmi floppy snd_page_alloc pcspkr i5k_amb [last unloaded: btrfs] Pid: 28504, comm: btrfs-endio-wri Tainted: G W 2.6.39-rc2+ #35 Hewlett-Packard HP xw6600 Workstation/0A9Ch RIP: 0010:[] [] alloc_reserved_file_extent+0x9a/0x1e5 [btrfs] RSP: 0018:88000b4319f0 EFLAGS: 00010286 RAX: ffe4 RBX: 880009fdc438 RCX: 880020c216d0 RDX: 88000b4318c0 RSI: 00d5 RDI: RBP: 88000b431a70 R08: ffe4 R09: 880020c216d0 R10: 0001 R11: 88000b431b10 R12: 88000b431b10 R13: 00b2 R14: R15: 88002225f2f8 FS: () GS:88003e40() knlGS: CS: 0010 DS: ES: CR0: 8005003b CR2: 003738ca6940 CR3: 2a39a000 CR4: 06e0 DR0: DR1: DR2: DR3: DR6: 0ff0 DR7: 0400 Process btrfs-endio-wri (pid: 28504, threadinfo 88000b43, task 880032278000) Stack: 0001 88002a92 881d 038d 0005 88003aa38000 81481012 88000c3bb480 8800241d01c8 88000b431a60 880031a040a8 Call Trace: [] ? sub_preempt_count+0x97/0xaa [] run_clustered_refs+0x61b/0x700 [btrfs] [] ? sub_preempt_count+0xe/0xaa [] ? spin_lock+0xe/0x10 [btrfs] [] btrfs_run_delayed_refs+0xd1/0x1ab [btrfs] [] ? _raw_spin_unlock+0x4a/0x57 [] __btrfs_end_transaction+0x89/0x1ed [btrfs] [] btrfs_end_transaction+0x15/0x17 [btrfs] [] btrfs_finish_ordered_io+0x29c/0x2bf [btrfs] [] btrfs_writepage_end_io_hook+0x81/0x8d [btrfs] [] end_bio_extent_writepage+0xae/0x159 [btrfs] [] bio_endio+0x2d/0x2f [] end_workqueue_fn+0x111/0x120 [btrfs] [] worker_loop+0x192/0x4d1 [btrfs] [] ? btrfs_queue_worker+0x22c/0x22c [btrfs] [] kthread+0xa0/0xa8 [] ? trace_hardirqs_on_caller+0x111/0x135 [] kernel_thread_helper+0x4/0x10 [] ? retint_restore_args+0x13/0x13 [] ? __init_kthread_worker+0x5b/0x5b [] ? gs_change+0x13/0x13 Code: 44 8b 45 90 0f 84 58 01 00 00 80 88 88 00 00 00 08 41 83 c0 18 4c 89 e1 48 8b 72 20 4c 89 ff 48 89 c2 e8 1f b4 ff ff 85 c0 74 04<0f> 0b eb fe 48 8b 03 48 89 45 c8 8b 73 40 48 89 c7 e8 bc 98 ff RIP [] alloc_reserved_file_extent+0x9a/0x1e5 [btrfs] RSP ---[ end trace 81d1c68cb00af83e ]--- This is because we have been releasing the delalloc bytes before ending the transaction. However the way we make allocations, any updates to the extent_tree are delayed and then run when the transaction runs, so we still have plenty of space that we need to use. So instead release the delalloc bytes _after_ we end the transaction so that we don't get this false ENOSPC. Thanks, Signed-off-by: Josef Bacik --- fs/btrfs/inode.c | 8 ++-- 1 files changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index ade00e7..b1e5b11 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1783,9 +1783,13 @@ out: if (trans) btrfs_end_transaction_nolock(trans, root); } else { - btrfs_delalloc_release_metadata(inode, ordered_extent->len); if (trans) btrfs_end_transaction(trans, root); + /* + * Release after the transaction ends so it covers the delayed + * ref updates + */ + btrfs_delalloc_release_metadata(inode, ordered_extent->len); I think calling end_transaction doesn't guarantee you that all delayed refs have run, only if end_transaction leads to commit transaction. Another problem I see is that commit_transaction just uses the block_rsv of whatever trans happened to call commit, even if the trans->block_rsv have been set to a different block_rsv than trans_block_rsv or delalloc_block_rsv. In other words, the relayed_refs are run from a non- deterministic block_rsv. But it's late, I'll think more about it tomorrow. Yeah you are right, not all delayed refs will be run, but hopefully the amount that we put into the delayed refs tree from the amount we created in making our new extents will be run, which will be enough for the math to come out right. Hopefully ;), Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@
Re: [PATCH] Btrfs: do not release delalloc space until after we end the transaction
On 04/13/2011 08:26 PM, Yan, Zheng wrote: On Thu, Apr 14, 2011 at 2:54 AM, Josef Bacik wrote: There have been many sporadic reports of the following panic [ cut here ] kernel BUG at fs/btrfs/extent-tree.c:5498! invalid opcode: [#1] PREEMPT SMP last sysfs file: /sys/devices/system/cpu/cpu7/cache/index2/shared_cpu_map CPU 7 Modules linked in: btrfs zlib_deflate libcrc32c netconsole configfs ipt_MASQUERADE iptable_nat nf_nat bridge stp llc sunrpc cpufreq_ondemand acpi_cpufreq freq_table mperf xt_physdev ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables ipv6 dm_multipath kvm uinput snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd hp_wmi i5400_edac sparse_keymap iTCO_wdt rfkill edac_core tg3 shpchp iTCO_vendor_support soundcore wmi floppy snd_page_alloc pcspkr i5k_amb [last unloaded: btrfs] Pid: 28504, comm: btrfs-endio-wri Tainted: GW 2.6.39-rc2+ #35 Hewlett-Packard HP xw6600 Workstation/0A9Ch RIP: 0010:[] [] alloc_reserved_file_extent+0x9a/0x1e5 [btrfs] RSP: 0018:88000b4319f0 EFLAGS: 00010286 RAX: ffe4 RBX: 880009fdc438 RCX: 880020c216d0 RDX: 88000b4318c0 RSI: 00d5 RDI: RBP: 88000b431a70 R08: ffe4 R09: 880020c216d0 R10: 0001 R11: 88000b431b10 R12: 88000b431b10 R13: 00b2 R14: R15: 88002225f2f8 FS: () GS:88003e40() knlGS: CS: 0010 DS: ES: CR0: 8005003b CR2: 003738ca6940 CR3: 2a39a000 CR4: 06e0 DR0: DR1: DR2: DR3: DR6: 0ff0 DR7: 0400 Process btrfs-endio-wri (pid: 28504, threadinfo 88000b43, task 880032278000) Stack: 0001 88002a92 881d 038d 0005 88003aa38000 81481012 88000c3bb480 8800241d01c8 88000b431a60 880031a040a8 Call Trace: [] ? sub_preempt_count+0x97/0xaa [] run_clustered_refs+0x61b/0x700 [btrfs] [] ? sub_preempt_count+0xe/0xaa [] ? spin_lock+0xe/0x10 [btrfs] [] btrfs_run_delayed_refs+0xd1/0x1ab [btrfs] [] ? _raw_spin_unlock+0x4a/0x57 [] __btrfs_end_transaction+0x89/0x1ed [btrfs] [] btrfs_end_transaction+0x15/0x17 [btrfs] [] btrfs_finish_ordered_io+0x29c/0x2bf [btrfs] [] btrfs_writepage_end_io_hook+0x81/0x8d [btrfs] [] end_bio_extent_writepage+0xae/0x159 [btrfs] [] bio_endio+0x2d/0x2f [] end_workqueue_fn+0x111/0x120 [btrfs] [] worker_loop+0x192/0x4d1 [btrfs] [] ? btrfs_queue_worker+0x22c/0x22c [btrfs] [] kthread+0xa0/0xa8 [] ? trace_hardirqs_on_caller+0x111/0x135 [] kernel_thread_helper+0x4/0x10 [] ? retint_restore_args+0x13/0x13 [] ? __init_kthread_worker+0x5b/0x5b [] ? gs_change+0x13/0x13 Code: 44 8b 45 90 0f 84 58 01 00 00 80 88 88 00 00 00 08 41 83 c0 18 4c 89 e1 48 8b 72 20 4c 89 ff 48 89 c2 e8 1f b4 ff ff 85 c0 74 04<0f> 0b eb fe 48 8b 03 48 89 45 c8 8b 73 40 48 89 c7 e8 bc 98 ff RIP [] alloc_reserved_file_extent+0x9a/0x1e5 [btrfs] RSP ---[ end trace 81d1c68cb00af83e ]--- This is because we have been releasing the delalloc bytes before ending the transaction. However the way we make allocations, any updates to the extent_tree are delayed and then run when the transaction runs, so we still have plenty of space that we need to use. So instead release the delalloc bytes _after_ we end the transaction so that we don't get this false ENOSPC. Thanks, This is wrong, because btrfs_run_delayed_refs uses global block reservation. I don't see anywhere in the delayed ref code that specifically uses the global block reserve, where is that? And if that is what is supposed to happen, why are we charging the metadata we will use for modifying the extent tree to the delalloc reserve? It seems to me we should either 1) Be using the delalloc block reserve for running the delayed ref's that are created by inserting our extent, since that is where the reservation currently is made, or 2) Stop charging the reservations for modifying the extent tree to the delalloc block reserve and charge it instead to the global reserve, and then actually make sure that the global reserve is used when we do the delayed ref updating. Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html