- 13 5月, 2016 1 次提交
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由 Filipe Manana 提交于
Before we start the actual relocation process of a block group, we do calls to flush delalloc of all inodes and then wait for ordered extents to complete. However we do these flush calls just to make sure we don't race with concurrent tasks that have actually already started to run delalloc and have allocated an extent from the block group we want to relocate, right before we set it to readonly mode, but have not yet created the respective ordered extents. The flush calls make us wait for such concurrent tasks because they end up calling filemap_fdatawrite_range() (through btrfs_start_delalloc_roots() -> __start_delalloc_inodes() -> btrfs_alloc_delalloc_work() -> btrfs_run_delalloc_work()) which ends up serializing us with those tasks due to attempts to lock the same pages (and the delalloc flush procedure calls the allocator and creates the ordered extents before unlocking the pages). These flushing calls not only make us waste time (cpu, IO) but also reduce the chances of writing larger extents (applications might be writing to contiguous ranges and we flush before they finish dirtying the whole ranges). So make sure we don't flush delalloc and just wait for concurrent tasks that have already started flushing delalloc and have allocated an extent from the block group we are about to relocate. This change also ends up fixing a race with direct IO writes that makes relocation not wait for direct IO ordered extents. This race is illustrated by the following diagram: CPU 1 CPU 2 btrfs_relocate_block_group(bg X) starts direct IO write, target inode currently has no ordered extents ongoing nor dirty pages (delalloc regions), therefore the root for our inode is not in the list fs_info->ordered_roots btrfs_direct_IO() __blockdev_direct_IO() btrfs_get_blocks_direct() btrfs_lock_extent_direct() locks range in the io tree btrfs_new_extent_direct() btrfs_reserve_extent() --> extent allocated from bg X btrfs_inc_block_group_ro(bg X) btrfs_start_delalloc_roots() __start_delalloc_inodes() --> does nothing, no dealloc ranges in the inode's io tree so the inode's root is not in the list fs_info->delalloc_roots btrfs_wait_ordered_roots() --> does not find the inode's root in the list fs_info->ordered_roots --> ends up not waiting for the direct IO write started by the task at CPU 2 relocate_block_group(rc->stage == MOVE_DATA_EXTENTS) prepare_to_relocate() btrfs_commit_transaction() iterates the extent tree, using its commit root and moves extents into new locations btrfs_add_ordered_extent_dio() --> now a ordered extent is created and added to the list root->ordered_extents and the root added to the list fs_info->ordered_roots --> this is too late and the task at CPU 1 already started the relocation btrfs_commit_transaction() btrfs_finish_ordered_io() btrfs_alloc_reserved_file_extent() --> adds delayed data reference for the extent allocated from bg X relocate_block_group(rc->stage == UPDATE_DATA_PTRS) prepare_to_relocate() btrfs_commit_transaction() --> delayed refs are run, so an extent item for the allocated extent from bg X is added to extent tree --> commit roots are switched, so the next scan in the extent tree will see the extent item sees the extent in the extent tree When this happens the relocation produces the following warning when it finishes: [ 7260.832836] ------------[ cut here ]------------ [ 7260.834653] WARNING: CPU: 5 PID: 6765 at fs/btrfs/relocation.c:4318 btrfs_relocate_block_group+0x245/0x2a1 [btrfs]() [ 7260.838268] Modules linked in: btrfs crc32c_generic xor ppdev raid6_pq psmouse sg acpi_cpufreq evdev i2c_piix4 tpm_tis serio_raw tpm i2c_core pcspkr parport_pc [ 7260.850935] CPU: 5 PID: 6765 Comm: btrfs Not tainted 4.5.0-rc6-btrfs-next-28+ #1 [ 7260.852998] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [ 7260.852998] 0000000000000000 ffff88020bf57bc0 ffffffff812648b3 0000000000000000 [ 7260.852998] 0000000000000009 ffff88020bf57bf8 ffffffff81051608 ffffffffa03c1b2d [ 7260.852998] ffff8800b2bbb800 0000000000000000 ffff8800b17bcc58 ffff8800399dd000 [ 7260.852998] Call Trace: [ 7260.852998] [<ffffffff812648b3>] dump_stack+0x67/0x90 [ 7260.852998] [<ffffffff81051608>] warn_slowpath_common+0x99/0xb2 [ 7260.852998] [<ffffffffa03c1b2d>] ? btrfs_relocate_block_group+0x245/0x2a1 [btrfs] [ 7260.852998] [<ffffffff810516d4>] warn_slowpath_null+0x1a/0x1c [ 7260.852998] [<ffffffffa03c1b2d>] btrfs_relocate_block_group+0x245/0x2a1 [btrfs] [ 7260.852998] [<ffffffffa039d9de>] btrfs_relocate_chunk.isra.29+0x66/0xdb [btrfs] [ 7260.852998] [<ffffffffa039f314>] btrfs_balance+0xde1/0xe4e [btrfs] [ 7260.852998] [<ffffffff8127d671>] ? debug_smp_processor_id+0x17/0x19 [ 7260.852998] [<ffffffffa03a9583>] btrfs_ioctl_balance+0x255/0x2d3 [btrfs] [ 7260.852998] [<ffffffffa03ac96a>] btrfs_ioctl+0x11e0/0x1dff [btrfs] [ 7260.852998] [<ffffffff811451df>] ? handle_mm_fault+0x443/0xd63 [ 7260.852998] [<ffffffff81491817>] ? _raw_spin_unlock+0x31/0x44 [ 7260.852998] [<ffffffff8108b36a>] ? arch_local_irq_save+0x9/0xc [ 7260.852998] [<ffffffff811876ab>] vfs_ioctl+0x18/0x34 [ 7260.852998] [<ffffffff81187cb2>] do_vfs_ioctl+0x550/0x5be [ 7260.852998] [<ffffffff81190c30>] ? __fget_light+0x4d/0x71 [ 7260.852998] [<ffffffff81187d77>] SyS_ioctl+0x57/0x79 [ 7260.852998] [<ffffffff81492017>] entry_SYSCALL_64_fastpath+0x12/0x6b [ 7260.893268] ---[ end trace eb7803b24ebab8ad ]--- This is because at the end of the first stage, in relocate_block_group(), we commit the current transaction, which makes delayed refs run, the commit roots are switched and so the second stage will find the extent item that the ordered extent added to the delayed refs. But this extent was not moved (ordered extent completed after first stage finished), so at the end of the relocation our block group item still has a positive used bytes counter, triggering a warning at the end of btrfs_relocate_block_group(). Later on when trying to read the extent contents from disk we hit a BUG_ON() due to the inability to map a block with a logical address that belongs to the block group we relocated and is no longer valid, resulting in the following trace: [ 7344.885290] BTRFS critical (device sdi): unable to find logical 12845056 len 4096 [ 7344.887518] ------------[ cut here ]------------ [ 7344.888431] kernel BUG at fs/btrfs/inode.c:1833! [ 7344.888431] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 7344.888431] Modules linked in: btrfs crc32c_generic xor ppdev raid6_pq psmouse sg acpi_cpufreq evdev i2c_piix4 tpm_tis serio_raw tpm i2c_core pcspkr parport_pc [ 7344.888431] CPU: 0 PID: 6831 Comm: od Tainted: G W 4.5.0-rc6-btrfs-next-28+ #1 [ 7344.888431] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [ 7344.888431] task: ffff880215818600 ti: ffff880204684000 task.ti: ffff880204684000 [ 7344.888431] RIP: 0010:[<ffffffffa037c88c>] [<ffffffffa037c88c>] btrfs_merge_bio_hook+0x54/0x6b [btrfs] [ 7344.888431] RSP: 0018:ffff8802046878f0 EFLAGS: 00010282 [ 7344.888431] RAX: 00000000ffffffea RBX: 0000000000001000 RCX: 0000000000000001 [ 7344.888431] RDX: ffff88023ec0f950 RSI: ffffffff8183b638 RDI: 00000000ffffffff [ 7344.888431] RBP: ffff880204687908 R08: 0000000000000001 R09: 0000000000000000 [ 7344.888431] R10: ffff880204687770 R11: ffffffff82f2d52d R12: 0000000000001000 [ 7344.888431] R13: ffff88021afbfee8 R14: 0000000000006208 R15: ffff88006cd199b0 [ 7344.888431] FS: 00007f1f9e1d6700(0000) GS:ffff88023ec00000(0000) knlGS:0000000000000000 [ 7344.888431] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 7344.888431] CR2: 00007f1f9dc8cb60 CR3: 000000023e3b6000 CR4: 00000000000006f0 [ 7344.888431] Stack: [ 7344.888431] 0000000000001000 0000000000001000 ffff880204687b98 ffff880204687950 [ 7344.888431] ffffffffa0395c8f ffffea0004d64d48 0000000000000000 0000000000001000 [ 7344.888431] ffffea0004d64d48 0000000000001000 0000000000000000 0000000000000000 [ 7344.888431] Call Trace: [ 7344.888431] [<ffffffffa0395c8f>] submit_extent_page+0xf5/0x16f [btrfs] [ 7344.888431] [<ffffffffa03970ac>] __do_readpage+0x4a0/0x4f1 [btrfs] [ 7344.888431] [<ffffffffa039680d>] ? btrfs_create_repair_bio+0xcb/0xcb [btrfs] [ 7344.888431] [<ffffffffa037eeb4>] ? btrfs_writepage_start_hook+0xbc/0xbc [btrfs] [ 7344.888431] [<ffffffff8108df55>] ? trace_hardirqs_on+0xd/0xf [ 7344.888431] [<ffffffffa039728c>] __do_contiguous_readpages.constprop.26+0xc2/0xe4 [btrfs] [ 7344.888431] [<ffffffffa037eeb4>] ? btrfs_writepage_start_hook+0xbc/0xbc [btrfs] [ 7344.888431] [<ffffffffa039739b>] __extent_readpages.constprop.25+0xed/0x100 [btrfs] [ 7344.888431] [<ffffffff81129d24>] ? lru_cache_add+0xe/0x10 [ 7344.888431] [<ffffffffa0397ea8>] extent_readpages+0x160/0x1aa [btrfs] [ 7344.888431] [<ffffffffa037eeb4>] ? btrfs_writepage_start_hook+0xbc/0xbc [btrfs] [ 7344.888431] [<ffffffff8115daad>] ? alloc_pages_current+0xa9/0xcd [ 7344.888431] [<ffffffffa037cdc9>] btrfs_readpages+0x1f/0x21 [btrfs] [ 7344.888431] [<ffffffff81128316>] __do_page_cache_readahead+0x168/0x1fc [ 7344.888431] [<ffffffff811285a0>] ondemand_readahead+0x1f6/0x207 [ 7344.888431] [<ffffffff811285a0>] ? ondemand_readahead+0x1f6/0x207 [ 7344.888431] [<ffffffff8111cf34>] ? pagecache_get_page+0x2b/0x154 [ 7344.888431] [<ffffffff8112870e>] page_cache_sync_readahead+0x3d/0x3f [ 7344.888431] [<ffffffff8111dbf7>] generic_file_read_iter+0x197/0x4e1 [ 7344.888431] [<ffffffff8117773a>] __vfs_read+0x79/0x9d [ 7344.888431] [<ffffffff81178050>] vfs_read+0x8f/0xd2 [ 7344.888431] [<ffffffff81178a38>] SyS_read+0x50/0x7e [ 7344.888431] [<ffffffff81492017>] entry_SYSCALL_64_fastpath+0x12/0x6b [ 7344.888431] Code: 8d 4d e8 45 31 c9 45 31 c0 48 8b 00 48 c1 e2 09 48 8b 80 80 fc ff ff 4c 89 65 e8 48 8b b8 f0 01 00 00 e8 1d 42 02 00 85 c0 79 02 <0f> 0b 4c 0 [ 7344.888431] RIP [<ffffffffa037c88c>] btrfs_merge_bio_hook+0x54/0x6b [btrfs] [ 7344.888431] RSP <ffff8802046878f0> [ 7344.970544] ---[ end trace eb7803b24ebab8ae ]--- Signed-off-by: NFilipe Manana <fdmanana@suse.com> Reviewed-by: NJosef Bacik <jbacik@fb.com> Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
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- 05 4月, 2016 1 次提交
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由 Kirill A. Shutemov 提交于
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: NMichal Hocko <mhocko@suse.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 02 3月, 2016 1 次提交
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由 Filipe Manana 提交于
While running a test with a mix of buffered IO and direct IO against the same files I hit a deadlock reported by the following trace: [11642.140352] INFO: task kworker/u32:3:15282 blocked for more than 120 seconds. [11642.142452] Not tainted 4.4.0-rc6-btrfs-next-21+ #1 [11642.143982] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [11642.146332] kworker/u32:3 D ffff880230ef7988 [11642.147737] systemd-journald[571]: Sent WATCHDOG=1 notification. [11642.149771] 0 15282 2 0x00000000 [11642.151205] Workqueue: btrfs-flush_delalloc btrfs_flush_delalloc_helper [btrfs] [11642.154074] ffff880230ef7988 0000000000000246 0000000000014ec0 ffff88023ec94ec0 [11642.156722] ffff880233fe8f80 ffff880230ef8000 ffff88023ec94ec0 7fffffffffffffff [11642.159205] 0000000000000002 ffffffff8147b7f9 ffff880230ef79a0 ffffffff8147b541 [11642.161403] Call Trace: [11642.162129] [<ffffffff8147b7f9>] ? bit_wait+0x2f/0x2f [11642.163396] [<ffffffff8147b541>] schedule+0x82/0x9a [11642.164871] [<ffffffff8147e7fe>] schedule_timeout+0x43/0x109 [11642.167020] [<ffffffff8147b7f9>] ? bit_wait+0x2f/0x2f [11642.167931] [<ffffffff8108afd1>] ? trace_hardirqs_on_caller+0x17b/0x197 [11642.182320] [<ffffffff8108affa>] ? trace_hardirqs_on+0xd/0xf [11642.183762] [<ffffffff810b079b>] ? timekeeping_get_ns+0xe/0x33 [11642.185308] [<ffffffff810b0f61>] ? ktime_get+0x41/0x52 [11642.186782] [<ffffffff8147ac08>] io_schedule_timeout+0xa0/0x102 [11642.188217] [<ffffffff8147ac08>] ? io_schedule_timeout+0xa0/0x102 [11642.189626] [<ffffffff8147b814>] bit_wait_io+0x1b/0x39 [11642.190803] [<ffffffff8147bb21>] __wait_on_bit_lock+0x4c/0x90 [11642.192158] [<ffffffff8111829f>] __lock_page+0x66/0x68 [11642.193379] [<ffffffff81082f29>] ? autoremove_wake_function+0x3a/0x3a [11642.194831] [<ffffffffa0450ddd>] lock_page+0x31/0x34 [btrfs] [11642.197068] [<ffffffffa0454e3b>] extent_write_cache_pages.isra.19.constprop.35+0x1af/0x2f4 [btrfs] [11642.199188] [<ffffffffa0455373>] extent_writepages+0x4b/0x5c [btrfs] [11642.200723] [<ffffffffa043c913>] ? btrfs_writepage_start_hook+0xce/0xce [btrfs] [11642.202465] [<ffffffffa043aa82>] btrfs_writepages+0x28/0x2a [btrfs] [11642.203836] [<ffffffff811236bc>] do_writepages+0x23/0x2c [11642.205624] [<ffffffff811198c9>] __filemap_fdatawrite_range+0x5a/0x61 [11642.207057] [<ffffffff81119946>] filemap_fdatawrite_range+0x13/0x15 [11642.208529] [<ffffffffa044f87e>] btrfs_start_ordered_extent+0xd0/0x1a1 [btrfs] [11642.210375] [<ffffffffa0462613>] ? btrfs_scrubparity_helper+0x140/0x33a [btrfs] [11642.212132] [<ffffffffa044f974>] btrfs_run_ordered_extent_work+0x25/0x34 [btrfs] [11642.213837] [<ffffffffa046262f>] btrfs_scrubparity_helper+0x15c/0x33a [btrfs] [11642.215457] [<ffffffffa046293b>] btrfs_flush_delalloc_helper+0xe/0x10 [btrfs] [11642.217095] [<ffffffff8106483e>] process_one_work+0x256/0x48b [11642.218324] [<ffffffff81064f20>] worker_thread+0x1f5/0x2a7 [11642.219466] [<ffffffff81064d2b>] ? rescuer_thread+0x289/0x289 [11642.220801] [<ffffffff8106a500>] kthread+0xd4/0xdc [11642.222032] [<ffffffff8106a42c>] ? kthread_parkme+0x24/0x24 [11642.223190] [<ffffffff8147fdef>] ret_from_fork+0x3f/0x70 [11642.224394] [<ffffffff8106a42c>] ? kthread_parkme+0x24/0x24 [11642.226295] 2 locks held by kworker/u32:3/15282: [11642.227273] #0: ("%s-%s""btrfs", name){++++.+}, at: [<ffffffff8106474d>] process_one_work+0x165/0x48b [11642.229412] #1: ((&work->normal_work)){+.+.+.}, at: [<ffffffff8106474d>] process_one_work+0x165/0x48b [11642.231414] INFO: task kworker/u32:8:15289 blocked for more than 120 seconds. [11642.232872] Not tainted 4.4.0-rc6-btrfs-next-21+ #1 [11642.234109] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [11642.235776] kworker/u32:8 D ffff88020de5f848 0 15289 2 0x00000000 [11642.237412] Workqueue: writeback wb_workfn (flush-btrfs-481) [11642.238670] ffff88020de5f848 0000000000000246 0000000000014ec0 ffff88023ed54ec0 [11642.240475] ffff88021b1ece40 ffff88020de60000 ffff88023ed54ec0 7fffffffffffffff [11642.242154] 0000000000000002 ffffffff8147b7f9 ffff88020de5f860 ffffffff8147b541 [11642.243715] Call Trace: [11642.244390] [<ffffffff8147b7f9>] ? bit_wait+0x2f/0x2f [11642.245432] [<ffffffff8147b541>] schedule+0x82/0x9a [11642.246392] [<ffffffff8147e7fe>] schedule_timeout+0x43/0x109 [11642.247479] [<ffffffff8147b7f9>] ? bit_wait+0x2f/0x2f [11642.248551] [<ffffffff8108afd1>] ? trace_hardirqs_on_caller+0x17b/0x197 [11642.249968] [<ffffffff8108affa>] ? trace_hardirqs_on+0xd/0xf [11642.251043] [<ffffffff810b079b>] ? timekeeping_get_ns+0xe/0x33 [11642.252202] [<ffffffff810b0f61>] ? ktime_get+0x41/0x52 [11642.253210] [<ffffffff8147ac08>] io_schedule_timeout+0xa0/0x102 [11642.254307] [<ffffffff8147ac08>] ? io_schedule_timeout+0xa0/0x102 [11642.256118] [<ffffffff8147b814>] bit_wait_io+0x1b/0x39 [11642.257131] [<ffffffff8147bb21>] __wait_on_bit_lock+0x4c/0x90 [11642.258200] [<ffffffff8111829f>] __lock_page+0x66/0x68 [11642.259168] [<ffffffff81082f29>] ? autoremove_wake_function+0x3a/0x3a [11642.260516] [<ffffffffa0450ddd>] lock_page+0x31/0x34 [btrfs] [11642.261841] [<ffffffffa0454e3b>] extent_write_cache_pages.isra.19.constprop.35+0x1af/0x2f4 [btrfs] [11642.263531] [<ffffffffa0455373>] extent_writepages+0x4b/0x5c [btrfs] [11642.264747] [<ffffffffa043c913>] ? btrfs_writepage_start_hook+0xce/0xce [btrfs] [11642.266148] [<ffffffffa043aa82>] btrfs_writepages+0x28/0x2a [btrfs] [11642.267264] [<ffffffff811236bc>] do_writepages+0x23/0x2c [11642.268280] [<ffffffff81192a2b>] __writeback_single_inode+0xda/0x5ba [11642.269407] [<ffffffff811939f0>] writeback_sb_inodes+0x27b/0x43d [11642.270476] [<ffffffff81193c28>] __writeback_inodes_wb+0x76/0xae [11642.271547] [<ffffffff81193ea6>] wb_writeback+0x19e/0x41c [11642.272588] [<ffffffff81194821>] wb_workfn+0x201/0x341 [11642.273523] [<ffffffff81194821>] ? wb_workfn+0x201/0x341 [11642.274479] [<ffffffff8106483e>] process_one_work+0x256/0x48b [11642.275497] [<ffffffff81064f20>] worker_thread+0x1f5/0x2a7 [11642.276518] [<ffffffff81064d2b>] ? rescuer_thread+0x289/0x289 [11642.277520] [<ffffffff81064d2b>] ? rescuer_thread+0x289/0x289 [11642.278517] [<ffffffff8106a500>] kthread+0xd4/0xdc [11642.279371] [<ffffffff8106a42c>] ? kthread_parkme+0x24/0x24 [11642.280468] [<ffffffff8147fdef>] ret_from_fork+0x3f/0x70 [11642.281607] [<ffffffff8106a42c>] ? kthread_parkme+0x24/0x24 [11642.282604] 3 locks held by kworker/u32:8/15289: [11642.283423] #0: ("writeback"){++++.+}, at: [<ffffffff8106474d>] process_one_work+0x165/0x48b [11642.285629] #1: ((&(&wb->dwork)->work)){+.+.+.}, at: [<ffffffff8106474d>] process_one_work+0x165/0x48b [11642.287538] #2: (&type->s_umount_key#37){+++++.}, at: [<ffffffff81171217>] trylock_super+0x1b/0x4b [11642.289423] INFO: task fdm-stress:26848 blocked for more than 120 seconds. [11642.290547] Not tainted 4.4.0-rc6-btrfs-next-21+ #1 [11642.291453] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [11642.292864] fdm-stress D ffff88022c107c20 0 26848 26591 0x00000000 [11642.294118] ffff88022c107c20 000000038108affa 0000000000014ec0 ffff88023ed54ec0 [11642.295602] ffff88013ab1ca40 ffff88022c108000 ffff8800b2fc19d0 00000000000e0fff [11642.297098] ffff8800b2fc19b0 ffff88022c107c88 ffff88022c107c38 ffffffff8147b541 [11642.298433] Call Trace: [11642.298896] [<ffffffff8147b541>] schedule+0x82/0x9a [11642.299738] [<ffffffffa045225d>] lock_extent_bits+0xfe/0x1a3 [btrfs] [11642.300833] [<ffffffff81082eef>] ? add_wait_queue_exclusive+0x44/0x44 [11642.301943] [<ffffffffa0447516>] lock_and_cleanup_extent_if_need+0x68/0x18e [btrfs] [11642.303270] [<ffffffffa04485ba>] __btrfs_buffered_write+0x238/0x4c1 [btrfs] [11642.304552] [<ffffffffa044b50a>] ? btrfs_file_write_iter+0x17c/0x408 [btrfs] [11642.305782] [<ffffffffa044b682>] btrfs_file_write_iter+0x2f4/0x408 [btrfs] [11642.306878] [<ffffffff8116e298>] __vfs_write+0x7c/0xa5 [11642.307729] [<ffffffff8116e7d1>] vfs_write+0x9d/0xe8 [11642.308602] [<ffffffff8116efbb>] SyS_write+0x50/0x7e [11642.309410] [<ffffffff8147fa97>] entry_SYSCALL_64_fastpath+0x12/0x6b [11642.310403] 3 locks held by fdm-stress/26848: [11642.311108] #0: (&f->f_pos_lock){+.+.+.}, at: [<ffffffff811877e8>] __fdget_pos+0x3a/0x40 [11642.312578] #1: (sb_writers#11){.+.+.+}, at: [<ffffffff811706ee>] __sb_start_write+0x5f/0xb0 [11642.314170] #2: (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<ffffffffa044b401>] btrfs_file_write_iter+0x73/0x408 [btrfs] [11642.316796] INFO: task fdm-stress:26849 blocked for more than 120 seconds. [11642.317842] Not tainted 4.4.0-rc6-btrfs-next-21+ #1 [11642.318691] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [11642.319959] fdm-stress D ffff8801964ffa68 0 26849 26591 0x00000000 [11642.321312] ffff8801964ffa68 00ff8801e9975f80 0000000000014ec0 ffff88023ed94ec0 [11642.322555] ffff8800b00b4840 ffff880196500000 ffff8801e9975f20 0000000000000002 [11642.323715] ffff8801e9975f18 ffff8800b00b4840 ffff8801964ffa80 ffffffff8147b541 [11642.325096] Call Trace: [11642.325532] [<ffffffff8147b541>] schedule+0x82/0x9a [11642.326303] [<ffffffff8147e7fe>] schedule_timeout+0x43/0x109 [11642.327180] [<ffffffff8108ae40>] ? mark_held_locks+0x5e/0x74 [11642.328114] [<ffffffff8147f30e>] ? _raw_spin_unlock_irq+0x2c/0x4a [11642.329051] [<ffffffff8108afd1>] ? trace_hardirqs_on_caller+0x17b/0x197 [11642.330053] [<ffffffff8147bceb>] __wait_for_common+0x109/0x147 [11642.330952] [<ffffffff8147bceb>] ? __wait_for_common+0x109/0x147 [11642.331869] [<ffffffff8147e7bb>] ? usleep_range+0x4a/0x4a [11642.332925] [<ffffffff81074075>] ? wake_up_q+0x47/0x47 [11642.333736] [<ffffffff8147bd4d>] wait_for_completion+0x24/0x26 [11642.334672] [<ffffffffa044f5ce>] btrfs_wait_ordered_extents+0x1c8/0x217 [btrfs] [11642.335858] [<ffffffffa0465b5a>] btrfs_mksubvol+0x224/0x45d [btrfs] [11642.336854] [<ffffffff81082eef>] ? add_wait_queue_exclusive+0x44/0x44 [11642.337820] [<ffffffffa0465edb>] btrfs_ioctl_snap_create_transid+0x148/0x17a [btrfs] [11642.339026] [<ffffffffa046603b>] btrfs_ioctl_snap_create_v2+0xc7/0x110 [btrfs] [11642.340214] [<ffffffffa0468582>] btrfs_ioctl+0x590/0x27bd [btrfs] [11642.341123] [<ffffffff8147dc00>] ? mutex_unlock+0xe/0x10 [11642.341934] [<ffffffffa00fa6e9>] ? ext4_file_write_iter+0x2a3/0x36f [ext4] [11642.342936] [<ffffffff8108895d>] ? __lock_is_held+0x3c/0x57 [11642.343772] [<ffffffff81186a1d>] ? rcu_read_unlock+0x3e/0x5d [11642.344673] [<ffffffff8117dc95>] do_vfs_ioctl+0x458/0x4dc [11642.346024] [<ffffffff81186bbe>] ? __fget_light+0x62/0x71 [11642.346873] [<ffffffff8117dd70>] SyS_ioctl+0x57/0x79 [11642.347720] [<ffffffff8147fa97>] entry_SYSCALL_64_fastpath+0x12/0x6b [11642.350222] 4 locks held by fdm-stress/26849: [11642.350898] #0: (sb_writers#11){.+.+.+}, at: [<ffffffff811706ee>] __sb_start_write+0x5f/0xb0 [11642.352375] #1: (&type->i_mutex_dir_key#4/1){+.+.+.}, at: [<ffffffffa0465981>] btrfs_mksubvol+0x4b/0x45d [btrfs] [11642.354072] #2: (&fs_info->subvol_sem){++++..}, at: [<ffffffffa0465a2a>] btrfs_mksubvol+0xf4/0x45d [btrfs] [11642.355647] #3: (&root->ordered_extent_mutex){+.+...}, at: [<ffffffffa044f456>] btrfs_wait_ordered_extents+0x50/0x217 [btrfs] [11642.357516] INFO: task fdm-stress:26850 blocked for more than 120 seconds. [11642.358508] Not tainted 4.4.0-rc6-btrfs-next-21+ #1 [11642.359376] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [11642.368625] fdm-stress D ffff88021f167688 0 26850 26591 0x00000000 [11642.369716] ffff88021f167688 0000000000000001 0000000000014ec0 ffff88023edd4ec0 [11642.370950] ffff880128a98680 ffff88021f168000 ffff88023edd4ec0 7fffffffffffffff [11642.372210] 0000000000000002 ffffffff8147b7f9 ffff88021f1676a0 ffffffff8147b541 [11642.373430] Call Trace: [11642.373853] [<ffffffff8147b7f9>] ? bit_wait+0x2f/0x2f [11642.374623] [<ffffffff8147b541>] schedule+0x82/0x9a [11642.375948] [<ffffffff8147e7fe>] schedule_timeout+0x43/0x109 [11642.376862] [<ffffffff8147b7f9>] ? bit_wait+0x2f/0x2f [11642.377637] [<ffffffff8108afd1>] ? trace_hardirqs_on_caller+0x17b/0x197 [11642.378610] [<ffffffff8108affa>] ? trace_hardirqs_on+0xd/0xf [11642.379457] [<ffffffff810b079b>] ? timekeeping_get_ns+0xe/0x33 [11642.380366] [<ffffffff810b0f61>] ? ktime_get+0x41/0x52 [11642.381353] [<ffffffff8147ac08>] io_schedule_timeout+0xa0/0x102 [11642.382255] [<ffffffff8147ac08>] ? io_schedule_timeout+0xa0/0x102 [11642.383162] [<ffffffff8147b814>] bit_wait_io+0x1b/0x39 [11642.383945] [<ffffffff8147bb21>] __wait_on_bit_lock+0x4c/0x90 [11642.384875] [<ffffffff8111829f>] __lock_page+0x66/0x68 [11642.385749] [<ffffffff81082f29>] ? autoremove_wake_function+0x3a/0x3a [11642.386721] [<ffffffffa0450ddd>] lock_page+0x31/0x34 [btrfs] [11642.387596] [<ffffffffa0454e3b>] extent_write_cache_pages.isra.19.constprop.35+0x1af/0x2f4 [btrfs] [11642.389030] [<ffffffffa0455373>] extent_writepages+0x4b/0x5c [btrfs] [11642.389973] [<ffffffff810a25ad>] ? rcu_read_lock_sched_held+0x61/0x69 [11642.390939] [<ffffffffa043c913>] ? btrfs_writepage_start_hook+0xce/0xce [btrfs] [11642.392271] [<ffffffffa0451c32>] ? __clear_extent_bit+0x26e/0x2c0 [btrfs] [11642.393305] [<ffffffffa043aa82>] btrfs_writepages+0x28/0x2a [btrfs] [11642.394239] [<ffffffff811236bc>] do_writepages+0x23/0x2c [11642.395045] [<ffffffff811198c9>] __filemap_fdatawrite_range+0x5a/0x61 [11642.395991] [<ffffffff81119946>] filemap_fdatawrite_range+0x13/0x15 [11642.397144] [<ffffffffa044f87e>] btrfs_start_ordered_extent+0xd0/0x1a1 [btrfs] [11642.398392] [<ffffffffa0452094>] ? clear_extent_bit+0x17/0x19 [btrfs] [11642.399363] [<ffffffffa0445945>] btrfs_get_blocks_direct+0x12b/0x61c [btrfs] [11642.400445] [<ffffffff8119f7a1>] ? dio_bio_add_page+0x3d/0x54 [11642.401309] [<ffffffff8119fa93>] ? submit_page_section+0x7b/0x111 [11642.402213] [<ffffffff811a0258>] do_blockdev_direct_IO+0x685/0xc24 [11642.403139] [<ffffffffa044581a>] ? btrfs_page_exists_in_range+0x1a1/0x1a1 [btrfs] [11642.404360] [<ffffffffa043d267>] ? btrfs_get_extent_fiemap+0x1c0/0x1c0 [btrfs] [11642.406187] [<ffffffff811a0828>] __blockdev_direct_IO+0x31/0x33 [11642.407070] [<ffffffff811a0828>] ? __blockdev_direct_IO+0x31/0x33 [11642.407990] [<ffffffffa043d267>] ? btrfs_get_extent_fiemap+0x1c0/0x1c0 [btrfs] [11642.409192] [<ffffffffa043b4ca>] btrfs_direct_IO+0x1c7/0x27e [btrfs] [11642.410146] [<ffffffffa043d267>] ? btrfs_get_extent_fiemap+0x1c0/0x1c0 [btrfs] [11642.411291] [<ffffffff81119a2c>] generic_file_read_iter+0x89/0x4e1 [11642.412263] [<ffffffff8108ac05>] ? mark_lock+0x24/0x201 [11642.413057] [<ffffffff8116e1f8>] __vfs_read+0x79/0x9d [11642.413897] [<ffffffff8116e6f1>] vfs_read+0x8f/0xd2 [11642.414708] [<ffffffff8116ef3d>] SyS_read+0x50/0x7e [11642.415573] [<ffffffff8147fa97>] entry_SYSCALL_64_fastpath+0x12/0x6b [11642.416572] 1 lock held by fdm-stress/26850: [11642.417345] #0: (&f->f_pos_lock){+.+.+.}, at: [<ffffffff811877e8>] __fdget_pos+0x3a/0x40 [11642.418703] INFO: task fdm-stress:26851 blocked for more than 120 seconds. [11642.419698] Not tainted 4.4.0-rc6-btrfs-next-21+ #1 [11642.420612] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [11642.421807] fdm-stress D ffff880196483d28 0 26851 26591 0x00000000 [11642.422878] ffff880196483d28 00ff8801c8f60740 0000000000014ec0 ffff88023ed94ec0 [11642.424149] ffff8801c8f60740 ffff880196484000 0000000000000246 ffff8801c8f60740 [11642.425374] ffff8801bb711840 ffff8801bb711878 ffff880196483d40 ffffffff8147b541 [11642.426591] Call Trace: [11642.427013] [<ffffffff8147b541>] schedule+0x82/0x9a [11642.427856] [<ffffffff8147b6d5>] schedule_preempt_disabled+0x18/0x24 [11642.428852] [<ffffffff8147c23a>] mutex_lock_nested+0x1d7/0x3b4 [11642.429743] [<ffffffffa044f456>] ? btrfs_wait_ordered_extents+0x50/0x217 [btrfs] [11642.430911] [<ffffffffa044f456>] btrfs_wait_ordered_extents+0x50/0x217 [btrfs] [11642.432102] [<ffffffffa044f674>] ? btrfs_wait_ordered_roots+0x57/0x191 [btrfs] [11642.433259] [<ffffffffa044f456>] ? btrfs_wait_ordered_extents+0x50/0x217 [btrfs] [11642.434431] [<ffffffffa044f6ea>] btrfs_wait_ordered_roots+0xcd/0x191 [btrfs] [11642.436079] [<ffffffffa0410cab>] btrfs_sync_fs+0xe0/0x1ad [btrfs] [11642.437009] [<ffffffff81197900>] ? SyS_tee+0x23c/0x23c [11642.437860] [<ffffffff81197920>] sync_fs_one_sb+0x20/0x22 [11642.438723] [<ffffffff81171435>] iterate_supers+0x75/0xc2 [11642.439597] [<ffffffff81197d00>] sys_sync+0x52/0x80 [11642.440454] [<ffffffff8147fa97>] entry_SYSCALL_64_fastpath+0x12/0x6b [11642.441533] 3 locks held by fdm-stress/26851: [11642.442370] #0: (&type->s_umount_key#37){+++++.}, at: [<ffffffff8117141f>] iterate_supers+0x5f/0xc2 [11642.444043] #1: (&fs_info->ordered_operations_mutex){+.+...}, at: [<ffffffffa044f661>] btrfs_wait_ordered_roots+0x44/0x191 [btrfs] [11642.446010] #2: (&root->ordered_extent_mutex){+.+...}, at: [<ffffffffa044f456>] btrfs_wait_ordered_extents+0x50/0x217 [btrfs] This happened because under specific timings the path for direct IO reads can deadlock with concurrent buffered writes. The diagram below shows how this happens for an example file that has the following layout: [ extent A ] [ extent B ] [ .... 0K 4K 8K CPU 1 CPU 2 CPU 3 DIO read against range [0K, 8K[ starts btrfs_direct_IO() --> calls btrfs_get_blocks_direct() which finds the extent map for the extent A and leaves the range [0K, 4K[ locked in the inode's io tree buffered write against range [4K, 8K[ starts __btrfs_buffered_write() --> dirties page at 4K a user space task calls sync for e.g or writepages() is invoked by mm writepages() run_delalloc_range() cow_file_range() --> ordered extent X for the buffered write is created and writeback starts --> calls btrfs_get_blocks_direct() again, without submitting first a bio for reading extent A, and finds the extent map for extent B --> calls lock_extent_direct() --> locks range [4K, 8K[ --> finds ordered extent X covering range [4K, 8K[ --> unlocks range [4K, 8K[ buffered write against range [0K, 8K[ starts __btrfs_buffered_write() prepare_pages() --> locks pages with offsets 0 and 4K lock_and_cleanup_extent_if_need() --> blocks attempting to lock range [0K, 8K[ in the inode's io tree, because the range [0, 4K[ is already locked by the direct IO task at CPU 1 --> calls btrfs_start_ordered_extent(oe X) btrfs_start_ordered_extent(oe X) --> At this point writeback for ordered extent X has not finished yet filemap_fdatawrite_range() btrfs_writepages() extent_writepages() extent_write_cache_pages() --> finds page with offset 0 with the writeback tag (and not dirty) --> tries to lock it --> deadlock, task at CPU 2 has the page locked and is blocked on the io range [0, 4K[ that was locked earlier by this task So fix this by falling back to a buffered read in the direct IO read path when an ordered extent for a buffered write is found. Signed-off-by: NFilipe Manana <fdmanana@suse.com> Reviewed-by: NLiu Bo <bo.li.liu@oracle.com> Signed-off-by: NChris Mason <clm@fb.com>
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- 18 2月, 2016 3 次提交
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由 Kinglong Mee 提交于
Cleanup. kmem_cache_destroy has support NULL argument checking, so drop the double null testing before calling it. Signed-off-by: NKinglong Mee <kinglongmee@gmail.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Deepa Dinamani 提交于
CURRENT_TIME macro is not appropriate for filesystems as it doesn't use the right granularity for filesystem timestamps. Use current_fs_time() instead. Signed-off-by: NDeepa Dinamani <deepa.kernel@gmail.com> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <jbacik@fb.com> Cc: linux-btrfs@vger.kernel.org Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Josef Bacik 提交于
truncate_space_check is using btrfs_csum_bytes_to_leaves() but forgetting to multiply by nodesize so we get an actual byte count. We need a tracepoint here so that we have the matching reserve for the release that will come later. Also add a comment to make clear what the intent of truncate_space_check is. Signed-off-by: NJosef Bacik <jbacik@fb.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 16 2月, 2016 1 次提交
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由 Filipe Manana 提交于
If a bio for a direct IO request fails, we were not setting the error in the parent bio (the main DIO bio), making us not return the error to user space in btrfs_direct_IO(), that is, it made __blockdev_direct_IO() return the number of bytes issued for IO and not the error a bio created and submitted by btrfs_submit_direct() got from the block layer. This essentially happens because when we call: dio_end_io(dio_bio, bio->bi_error); It does not set dio_bio->bi_error to the value of the second argument. So just add this missing assignment in endio callbacks, just as we do in the error path at btrfs_submit_direct() when we fail to clone the dio bio or allocate its private object. This follows the convention of what is done with other similar APIs such as bio_endio() where the caller is responsible for setting the bi_error field in the bio it passes as an argument to bio_endio(). This was detected by the new generic test cases in xfstests: 271, 272, 276 and 278. Which essentially setup a dm error target, then load the error table, do a direct IO write and unload the error table. They expect the write to fail with -EIO, which was not getting reported when testing against btrfs. Cc: stable@vger.kernel.org # 4.3+ Fixes: 4246a0b6 ("block: add a bi_error field to struct bio") Signed-off-by: NFilipe Manana <fdmanana@suse.com>
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- 11 2月, 2016 2 次提交
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由 David Sterba 提交于
The value of ctx->pos in the last readdir call is supposed to be set to INT_MAX due to 32bit compatibility, unless 'pos' is intentially set to a larger value, then it's LLONG_MAX. There's a report from PaX SIZE_OVERFLOW plugin that "ctx->pos++" overflows (https://forums.grsecurity.net/viewtopic.php?f=1&t=4284), on a 64bit arch, where the value is 0x7fffffffffffffff ie. LLONG_MAX before the increment. We can get to that situation like that: * emit all regular readdir entries * still in the same call to readdir, bump the last pos to INT_MAX * next call to readdir will not emit any entries, but will reach the bump code again, finds pos to be INT_MAX and sets it to LLONG_MAX Normally this is not a problem, but if we call readdir again, we'll find 'pos' set to LLONG_MAX and the unconditional increment will overflow. The report from Victor at (http://thread.gmane.org/gmane.comp.file-systems.btrfs/49500) with debugging print shows that pattern: Overflow: e Overflow: 7fffffff Overflow: 7fffffffffffffff PAX: size overflow detected in function btrfs_real_readdir fs/btrfs/inode.c:5760 cicus.935_282 max, count: 9, decl: pos; num: 0; context: dir_context; CPU: 0 PID: 2630 Comm: polkitd Not tainted 4.2.3-grsec #1 Hardware name: Gigabyte Technology Co., Ltd. H81ND2H/H81ND2H, BIOS F3 08/11/2015 ffffffff81901608 0000000000000000 ffffffff819015e6 ffffc90004973d48 ffffffff81742f0f 0000000000000007 ffffffff81901608 ffffc90004973d78 ffffffff811cb706 0000000000000000 ffff8800d47359e0 ffffc90004973ed8 Call Trace: [<ffffffff81742f0f>] dump_stack+0x4c/0x7f [<ffffffff811cb706>] report_size_overflow+0x36/0x40 [<ffffffff812ef0bc>] btrfs_real_readdir+0x69c/0x6d0 [<ffffffff811dafc8>] iterate_dir+0xa8/0x150 [<ffffffff811e6d8d>] ? __fget_light+0x2d/0x70 [<ffffffff811dba3a>] SyS_getdents+0xba/0x1c0 Overflow: 1a [<ffffffff811db070>] ? iterate_dir+0x150/0x150 [<ffffffff81749b69>] entry_SYSCALL_64_fastpath+0x12/0x83 The jump from 7fffffff to 7fffffffffffffff happens when new dir entries are not yet synced and are processed from the delayed list. Then the code could go to the bump section again even though it might not emit any new dir entries from the delayed list. The fix avoids entering the "bump" section again once we've finished emitting the entries, both for synced and delayed entries. References: https://forums.grsecurity.net/viewtopic.php?f=1&t=4284Reported-by: NVictor <services@swwu.com> CC: stable@vger.kernel.org Signed-off-by: NDavid Sterba <dsterba@suse.com> Tested-by: NHolger Hoffstätte <holger.hoffstaette@googlemail.com> Signed-off-by: NChris Mason <clm@fb.com>
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由 David Sterba 提交于
Readdir is initiated from userspace and is not on the critical writeback path, we don't need to use GFP_NOFS for allocations. Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 02 2月, 2016 8 次提交
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由 Chandan Rajendra 提交于
When extending a file by either "truncate up" or by writing beyond i_size, the page which had i_size needs to be marked "read only" so that future writes to the page via mmap interface causes btrfs_page_mkwrite() to be invoked. If not, a write performed after extending the file via the mmap interface will find the page to be writaeable and continue writing to the page without invoking btrfs_page_mkwrite() i.e. we end up writing to a file without reserving disk space. Signed-off-by: NChandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Chandan Rajendra 提交于
btrfs_getattr() returns PAGE_CACHE_SIZE as the block size. Since generic_fillattr() already does the right thing (by obtaining block size from inode->i_blkbits), just remove the statement from btrfs_getattr. Reviewed-by: NJosef Bacik <jbacik@fb.com> Signed-off-by: NChandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Chandan Rajendra 提交于
cow_file_range_inline() limits the size of an inline extent to PAGE_CACHE_SIZE. This breaks in subpagesize-blocksize scenarios. Fix this by comparing against root->sectorsize. Reviewed-by: NJosef Bacik <jbacik@fb.com> Signed-off-by: NChandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Chandan Rajendra 提交于
In subpagesize-blocksize scenario, map_length can be less than the length of a bio vector. Such a condition may cause btrfs_submit_direct_hook() to submit a zero length bio. Fix this by comparing map_length against block size rather than with bv_len. Signed-off-by: NChandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Chandan Rajendra 提交于
In subpagesize-blocksize scenario it is not sufficient to search using the first byte of the page to make sure that there are no ordered extents present across the page. Fix this. Signed-off-by: NChandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Chandan Rajendra 提交于
In subpagesize-blocksize scenario, if i_size occurs in a block which is not the last block in the page, then the space to be reserved should be calculated appropriately. Reviewed-by: NLiu Bo <bo.li.liu@oracle.com> Signed-off-by: NChandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Chandan Rajendra 提交于
While at it, this commit changes btrfs_truncate_page() to truncate sectorsized blocks instead of pages. Hence the function has been renamed to btrfs_truncate_block(). Signed-off-by: NChandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Chandan Rajendra 提交于
The direct I/O read's endio and corresponding repair functions work on page sized blocks. This commit adds the ability for direct I/O read to work on subpagesized blocks. Signed-off-by: NChandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 26 1月, 2016 1 次提交
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由 Filipe Manana 提交于
An fsync, using the fast path, can race with a concurrent lockless direct IO write and end up logging a file extent item that points to an extent that wasn't written to yet. This is because the fast fsync path collects ordered extents into a local list and then collects all the new extent maps to log file extent items based on them, while the direct IO write path creates the new extent map before it creates the corresponding ordered extent (and submitting the respective bio(s)). So fix this by making the direct IO write path create ordered extents before the extent maps and make the fast fsync path collect any new ordered extents after it collects the extent maps. Note that making the fsync handler call inode_dio_wait() (after acquiring the inode's i_mutex) would not work and lead to a deadlock when doing AIO, as through AIO we end up in a path where the fsync handler is called (through dio_aio_complete_work() -> dio_complete() -> vfs_fsync_range()) before the inode's dio counter is decremented (inode_dio_wait() waits for this counter to have a value of zero). Signed-off-by: NFilipe Manana <fdmanana@suse.com> Signed-off-by: NChris Mason <clm@fb.com>
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- 23 1月, 2016 1 次提交
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由 Al Viro 提交于
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 20 1月, 2016 2 次提交
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由 Zhao Lei 提交于
wait_for_snapshot_creation() is in same group with oher two: btrfs_start_write_no_snapshoting() btrfs_end_write_no_snapshoting() Rename wait_for_snapshot_creation() and move it into same place with other two. Signed-off-by: NZhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: NChris Mason <clm@fb.com>
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由 Filipe Manana 提交于
While running a stress test I ran into a deadlock when running the delayed iputs at transaction time, which produced the following report and trace: [ 886.399989] ============================================= [ 886.400871] [ INFO: possible recursive locking detected ] [ 886.401663] 4.4.0-rc6-btrfs-next-18+ #1 Not tainted [ 886.402384] --------------------------------------------- [ 886.403182] fio/8277 is trying to acquire lock: [ 886.403568] (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.403568] [ 886.403568] but task is already holding lock: [ 886.403568] (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.403568] [ 886.403568] other info that might help us debug this: [ 886.403568] Possible unsafe locking scenario: [ 886.403568] [ 886.403568] CPU0 [ 886.403568] ---- [ 886.403568] lock(&fs_info->delayed_iput_sem); [ 886.403568] lock(&fs_info->delayed_iput_sem); [ 886.403568] [ 886.403568] *** DEADLOCK *** [ 886.403568] [ 886.403568] May be due to missing lock nesting notation [ 886.403568] [ 886.403568] 3 locks held by fio/8277: [ 886.403568] #0: (sb_writers#11){.+.+.+}, at: [<ffffffff81174c4c>] __sb_start_write+0x5f/0xb0 [ 886.403568] #1: (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<ffffffffa054620d>] btrfs_file_write_iter+0x73/0x408 [btrfs] [ 886.403568] #2: (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.403568] [ 886.403568] stack backtrace: [ 886.403568] CPU: 6 PID: 8277 Comm: fio Not tainted 4.4.0-rc6-btrfs-next-18+ #1 [ 886.403568] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [ 886.403568] 0000000000000000 ffff88009f80f770 ffffffff8125d4fd ffffffff82af1fc0 [ 886.403568] ffff88009f80f830 ffffffff8108e5f9 0000000200000000 ffff88009fd92290 [ 886.403568] 0000000000000000 ffffffff82af1fc0 ffffffff829cfb01 00042b216d008804 [ 886.403568] Call Trace: [ 886.403568] [<ffffffff8125d4fd>] dump_stack+0x4e/0x79 [ 886.403568] [<ffffffff8108e5f9>] __lock_acquire+0xd42/0xf0b [ 886.403568] [<ffffffff810c22db>] ? __module_address+0xdf/0x108 [ 886.403568] [<ffffffff8108eb77>] lock_acquire+0x10d/0x194 [ 886.403568] [<ffffffff8108eb77>] ? lock_acquire+0x10d/0x194 [ 886.403568] [<ffffffffa0538823>] ? btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.489542] [<ffffffff8148556b>] down_read+0x3e/0x4d [ 886.489542] [<ffffffffa0538823>] ? btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.489542] [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.489542] [<ffffffffa0533953>] btrfs_commit_transaction+0x8f5/0x96e [btrfs] [ 886.489542] [<ffffffffa0521d7a>] flush_space+0x435/0x44a [btrfs] [ 886.489542] [<ffffffffa052218b>] ? reserve_metadata_bytes+0x26a/0x384 [btrfs] [ 886.489542] [<ffffffffa05221ae>] reserve_metadata_bytes+0x28d/0x384 [btrfs] [ 886.489542] [<ffffffffa052256c>] ? btrfs_block_rsv_refill+0x58/0x96 [btrfs] [ 886.489542] [<ffffffffa0522584>] btrfs_block_rsv_refill+0x70/0x96 [btrfs] [ 886.489542] [<ffffffffa053d747>] btrfs_evict_inode+0x394/0x55a [btrfs] [ 886.489542] [<ffffffff81188e31>] evict+0xa7/0x15c [ 886.489542] [<ffffffff81189878>] iput+0x1d3/0x266 [ 886.489542] [<ffffffffa053887c>] btrfs_run_delayed_iputs+0x8f/0xbf [btrfs] [ 886.489542] [<ffffffffa0533953>] btrfs_commit_transaction+0x8f5/0x96e [btrfs] [ 886.489542] [<ffffffff81085096>] ? signal_pending_state+0x31/0x31 [ 886.489542] [<ffffffffa0521191>] btrfs_alloc_data_chunk_ondemand+0x1d7/0x288 [btrfs] [ 886.489542] [<ffffffffa0521282>] btrfs_check_data_free_space+0x40/0x59 [btrfs] [ 886.489542] [<ffffffffa05228f5>] btrfs_delalloc_reserve_space+0x1e/0x4e [btrfs] [ 886.489542] [<ffffffffa053620a>] btrfs_direct_IO+0x10c/0x27e [btrfs] [ 886.489542] [<ffffffff8111d9a1>] generic_file_direct_write+0xb3/0x128 [ 886.489542] [<ffffffffa05463c3>] btrfs_file_write_iter+0x229/0x408 [btrfs] [ 886.489542] [<ffffffff8108ae38>] ? __lock_is_held+0x38/0x50 [ 886.489542] [<ffffffff8117279e>] __vfs_write+0x7c/0xa5 [ 886.489542] [<ffffffff81172cda>] vfs_write+0xa0/0xe4 [ 886.489542] [<ffffffff811734cc>] SyS_write+0x50/0x7e [ 886.489542] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [ 1081.852335] INFO: task fio:8244 blocked for more than 120 seconds. [ 1081.854348] Not tainted 4.4.0-rc6-btrfs-next-18+ #1 [ 1081.857560] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1081.863227] fio D ffff880213f9bb28 0 8244 8240 0x00000000 [ 1081.868719] ffff880213f9bb28 00ffffff810fc6b0 ffffffff0000000a ffff88023ed55240 [ 1081.872499] ffff880206b5d400 ffff880213f9c000 ffff88020a4d5318 ffff880206b5d400 [ 1081.876834] ffffffff00000001 ffff880206b5d400 ffff880213f9bb40 ffffffff81482ba4 [ 1081.880782] Call Trace: [ 1081.881793] [<ffffffff81482ba4>] schedule+0x7f/0x97 [ 1081.883340] [<ffffffff81485eb5>] rwsem_down_write_failed+0x2d5/0x325 [ 1081.895525] [<ffffffff8108d48d>] ? trace_hardirqs_on_caller+0x16/0x1ab [ 1081.897419] [<ffffffff81269723>] call_rwsem_down_write_failed+0x13/0x20 [ 1081.899251] [<ffffffff81269723>] ? call_rwsem_down_write_failed+0x13/0x20 [ 1081.901063] [<ffffffff81089fae>] ? __down_write_nested.isra.0+0x1f/0x21 [ 1081.902365] [<ffffffff814855bd>] down_write+0x43/0x57 [ 1081.903846] [<ffffffffa05211b0>] ? btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs] [ 1081.906078] [<ffffffffa05211b0>] btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs] [ 1081.908846] [<ffffffff8108d461>] ? mark_held_locks+0x56/0x6c [ 1081.910409] [<ffffffffa0521282>] btrfs_check_data_free_space+0x40/0x59 [btrfs] [ 1081.912482] [<ffffffffa05228f5>] btrfs_delalloc_reserve_space+0x1e/0x4e [btrfs] [ 1081.914597] [<ffffffffa053620a>] btrfs_direct_IO+0x10c/0x27e [btrfs] [ 1081.919037] [<ffffffff8111d9a1>] generic_file_direct_write+0xb3/0x128 [ 1081.920754] [<ffffffffa05463c3>] btrfs_file_write_iter+0x229/0x408 [btrfs] [ 1081.922496] [<ffffffff8108ae38>] ? __lock_is_held+0x38/0x50 [ 1081.923922] [<ffffffff8117279e>] __vfs_write+0x7c/0xa5 [ 1081.925275] [<ffffffff81172cda>] vfs_write+0xa0/0xe4 [ 1081.926584] [<ffffffff811734cc>] SyS_write+0x50/0x7e [ 1081.927968] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [ 1081.985293] INFO: lockdep is turned off. [ 1081.986132] INFO: task fio:8249 blocked for more than 120 seconds. [ 1081.987434] Not tainted 4.4.0-rc6-btrfs-next-18+ #1 [ 1081.988534] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1081.990147] fio D ffff880218febbb8 0 8249 8240 0x00000000 [ 1081.991626] ffff880218febbb8 00ffffff81486b8e ffff88020000000b ffff88023ed75240 [ 1081.993258] ffff8802120a9a00 ffff880218fec000 ffff88020a4d5318 ffff8802120a9a00 [ 1081.994850] ffffffff00000001 ffff8802120a9a00 ffff880218febbd0 ffffffff81482ba4 [ 1081.996485] Call Trace: [ 1081.997037] [<ffffffff81482ba4>] schedule+0x7f/0x97 [ 1081.998017] [<ffffffff81485eb5>] rwsem_down_write_failed+0x2d5/0x325 [ 1081.999241] [<ffffffff810852a5>] ? finish_wait+0x6d/0x76 [ 1082.000306] [<ffffffff81269723>] call_rwsem_down_write_failed+0x13/0x20 [ 1082.001533] [<ffffffff81269723>] ? call_rwsem_down_write_failed+0x13/0x20 [ 1082.002776] [<ffffffff81089fae>] ? __down_write_nested.isra.0+0x1f/0x21 [ 1082.003995] [<ffffffff814855bd>] down_write+0x43/0x57 [ 1082.005000] [<ffffffffa05211b0>] ? btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs] [ 1082.007403] [<ffffffffa05211b0>] btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs] [ 1082.008988] [<ffffffffa0545064>] btrfs_fallocate+0x7c1/0xc2f [btrfs] [ 1082.010193] [<ffffffff8108a1ba>] ? percpu_down_read+0x4e/0x77 [ 1082.011280] [<ffffffff81174c4c>] ? __sb_start_write+0x5f/0xb0 [ 1082.012265] [<ffffffff81174c4c>] ? __sb_start_write+0x5f/0xb0 [ 1082.013021] [<ffffffff811712e4>] vfs_fallocate+0x170/0x1ff [ 1082.013738] [<ffffffff81181ebb>] ioctl_preallocate+0x89/0x9b [ 1082.014778] [<ffffffff811822d7>] do_vfs_ioctl+0x40a/0x4ea [ 1082.015778] [<ffffffff81176ea7>] ? SYSC_newfstat+0x25/0x2e [ 1082.016806] [<ffffffff8118b4de>] ? __fget_light+0x4d/0x71 [ 1082.017789] [<ffffffff8118240e>] SyS_ioctl+0x57/0x79 [ 1082.018706] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f This happens because we can recursively acquire the semaphore fs_info->delayed_iput_sem when attempting to allocate space to satisfy a file write request as shown in the first trace above - when committing a transaction we acquire (down_read) the semaphore before running the delayed iputs, and when running a delayed iput() we can end up calling an inode's eviction handler, which in turn commits another transaction and attempts to acquire (down_read) again the semaphore to run more delayed iput operations. This results in a deadlock because if a task acquires multiple times a semaphore it should invoke down_read_nested() with a different lockdep class for each level of recursion. Fix this by simplifying the implementation and use a mutex instead that is acquired by the cleaner kthread before it runs the delayed iputs instead of always acquiring a semaphore before delayed references are run from anywhere. Fixes: d7c15171 (btrfs: Fix NO_SPACE bug caused by delayed-iput) Cc: stable@vger.kernel.org # 4.1+ Signed-off-by: NFilipe Manana <fdmanana@suse.com> Signed-off-by: NChris Mason <clm@fb.com>
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- 15 1月, 2016 1 次提交
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由 Vladimir Davydov 提交于
Mark those kmem allocations that are known to be easily triggered from userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to memcg. For the list, see below: - threadinfo - task_struct - task_delay_info - pid - cred - mm_struct - vm_area_struct and vm_region (nommu) - anon_vma and anon_vma_chain - signal_struct - sighand_struct - fs_struct - files_struct - fdtable and fdtable->full_fds_bits - dentry and external_name - inode for all filesystems. This is the most tedious part, because most filesystems overwrite the alloc_inode method. The list is far from complete, so feel free to add more objects. Nevertheless, it should be close to "account everything" approach and keep most workloads within bounds. Malevolent users will be able to breach the limit, but this was possible even with the former "account everything" approach (simply because it did not account everything in fact). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: NVladimir Davydov <vdavydov@virtuozzo.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NMichal Hocko <mhocko@suse.com> Cc: Tejun Heo <tj@kernel.org> Cc: Greg Thelen <gthelen@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 07 1月, 2016 10 次提交
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由 David Sterba 提交于
Replace the integers by enums for better readability. The value 2 does not have any meaning since a7175319 "Btrfs: do less aggressive btree readahead" (2009-01-22). Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 David Sterba 提交于
There are a few statically initialized arrays that can be made const. The remaining (like file_system_type, sysfs attributes or prop handlers) do not allow that due to type mismatch when passed to the APIs or because the structures are modified through other members. Signed-off-by: NDavid Sterba <dsterba@suse.com> -
由 David Sterba 提交于
* struct extent_io_ops * struct btrfs_free_space_op Signed-off-by: NDavid Sterba <dsterba@suse.com> -
由 Byongho Lee 提交于
We use many constants to represent size and offset value. And to make code readable we use '256 * 1024 * 1024' instead of '268435456' to represent '256MB'. However we can make far more readable with 'SZ_256MB' which is defined in the 'linux/sizes.h'. So this patch replaces 'xxx * 1024 * 1024' kind of expression with single 'SZ_xxxMB' if 'xxx' is a power of 2 then 'xxx * SZ_1M' if 'xxx' is not a power of 2. And I haven't touched to '4096' & '8192' because it's more intuitive than 'SZ_4KB' & 'SZ_8KB'. Signed-off-by: NByongho Lee <bhlee.kernel@gmail.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 David Sterba 提交于
Signed-off-by: NDavid Sterba <dsterba@suse.com> -
由 Byongho Lee 提交于
The inode argument is never used from the beginning, so remove it. Signed-off-by: NByongho Lee <bhlee.kernel@gmail.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 David Sterba 提交于
Although we prefer to use separate caches for various structs, it seems better not to do that for struct btrfs_delalloc_work. Objects of this type are allocated rarely, when transaction commit calls btrfs_start_delalloc_roots, requesting delayed iputs. The objects are temporary (with some IO involved) but still allocated and freed within __start_delalloc_inodes. Memory allocation failure is handled. The slab cache is empty most of the time (observed on several systems), so if we need to allocate a new slab object, the first one has to allocate a full page. In a potential case of low memory conditions this might fail with higher probability compared to using the generic slab caches. Signed-off-by: NDavid Sterba <dsterba@suse.com> -
由 David Sterba 提交于
Inodes for delayed iput allocate a trivial helper structure, let's place the list hook directly into the inode and save a kmalloc (killing a __GFP_NOFAIL as a bonus) at the cost of increasing size of btrfs_inode. The inode can be put into the delayed_iputs list more than once and we have to keep the count. This means we can't use the list_splice to process a bunch of inodes because we'd lost track of the count if the inode is put into the delayed iputs again while it's processed. Signed-off-by: NDavid Sterba <dsterba@suse.com> -
由 Josef Bacik 提交于
We hit this panic on a few of our boxes this week where we have an ordered_extent with an NULL inode. We do an igrab() of the inode in writepages, but weren't doing it in writepage which can be called directly from the VM on dirty pages. If the inode has been unlinked then we could have I_FREEING set which means igrab() would return NULL and we get this panic. Fix this by trying to igrab in btrfs_writepage, and if it returns NULL then just redirty the page and return AOP_WRITEPAGE_ACTIVATE; so the VM knows it wasn't successful. Thanks, Signed-off-by: NJosef Bacik <jbacik@fb.com> Reviewed-by: NLiu Bo <bo.li.liu@oracle.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Filipe Manana 提交于
If we failed to create a hard link we were not always releasing the the transaction handle we got before, resulting in a memory leak and preventing any other tasks from being able to commit the current transaction. Fix this by always releasing our transaction handle. Signed-off-by: NFilipe Manana <fdmanana@suse.com> Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
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- 01 1月, 2016 2 次提交
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由 Filipe Manana 提交于
We weren't accounting for the insertion of an inline extent item for the symlink inode nor that we need to update the parent inode item (through the call to btrfs_add_nondir()). So fix this by including two more transaction units. Signed-off-by: NFilipe Manana <fdmanana@suse.com> -
由 Filipe Manana 提交于
When we are creating a symlink we might fail with an error after we created its inode and added the corresponding directory indexes to its parent inode. In this case we end up never removing the directory indexes because the inode eviction handler, called for our symlink inode on the final iput(), only removes items associated with the symlink inode and not with the parent inode. Example: $ mkfs.btrfs -f /dev/sdi $ mount /dev/sdi /mnt $ touch /mnt/foo $ ln -s /mnt/foo /mnt/bar ln: failed to create symbolic link ‘bar’: Cannot allocate memory $ umount /mnt $ btrfsck /dev/sdi Checking filesystem on /dev/sdi UUID: d5acb5ba-31bd-42da-b456-89dca2e716e1 checking extents checking free space cache checking fs roots root 5 inode 258 errors 2001, no inode item, link count wrong unresolved ref dir 256 index 3 namelen 3 name bar filetype 7 errors 4, no inode ref found 131073 bytes used err is 1 total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 124305 file data blocks allocated: 262144 referenced 262144 btrfs-progs v4.2.3 So fix this by adding the directory index entries as the very last step of symlink creation. Signed-off-by: NFilipe Manana <fdmanana@suse.com>
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- 31 12月, 2015 1 次提交
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 17 12月, 2015 3 次提交
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由 Filipe Manana 提交于
When doing a direct IO write, __blockdev_direct_IO() can call the btrfs_get_blocks_direct() callback one or more times before it calls the btrfs_submit_direct() callback. However it can fail after calling the first callback and before calling the second callback, which is a problem because the first one creates ordered extents and the second one is the one that submits bios that cover the ordered extents created by the first one. That means the ordered extents will never complete nor have any of the flags BTRFS_ORDERED_IO_DONE / BTRFS_ORDERED_IOERR set, resulting in subsequent operations (such as other direct IO writes, buffered writes or hole punching) that lock the same IO range and lookup for ordered extents in the range to hang forever waiting for those ordered extents because they can not complete ever, since no bio was submitted. Fix this by tracking a range of created ordered extents that don't have yet corresponding bios submitted and completing the ordered extents in the range if __blockdev_direct_IO() fails with an error. Signed-off-by: NFilipe Manana <fdmanana@suse.com> -
由 Filipe Manana 提交于
If readpages() (triggered by defrag or buffered reads) is called while a direct IO write is in progress, we have a small time window where we can deadlock, resulting in traces like the following being generated: [84723.212993] INFO: task fio:2849 blocked for more than 120 seconds. [84723.214310] Tainted: G W 4.3.0-rc5-btrfs-next-17+ #1 [84723.215640] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [84723.217313] fio D ffff88023ec75218 0 2849 2835 0x00000000 [84723.218778] ffff880122dfb6e8 0000000000000092 0000000000000000 ffff88023ec75200 [84723.220458] ffff88000e05d2c0 ffff880122dfc000 ffff88023ec75200 7fffffffffffffff [84723.230597] 0000000000000002 ffffffff8147891a ffff880122dfb700 ffffffff8147856a [84723.232085] Call Trace: [84723.232625] [<ffffffff8147891a>] ? bit_wait+0x3c/0x3c [84723.233529] [<ffffffff8147856a>] schedule+0x7d/0x95 [84723.234398] [<ffffffff8147baa3>] schedule_timeout+0x43/0x10b [84723.235384] [<ffffffff810f82eb>] ? time_hardirqs_on+0x15/0x28 [84723.236426] [<ffffffff8108a23d>] ? trace_hardirqs_on+0xd/0xf [84723.237502] [<ffffffff810af8a3>] ? read_seqcount_begin.constprop.20+0x57/0x6d [84723.238807] [<ffffffff8108a09b>] ? trace_hardirqs_on_caller+0x16/0x1ab [84723.242012] [<ffffffff8108a23d>] ? trace_hardirqs_on+0xd/0xf [84723.243064] [<ffffffff810af2ad>] ? timekeeping_get_ns+0xe/0x33 [84723.244116] [<ffffffff810afa2e>] ? ktime_get+0x41/0x52 [84723.245029] [<ffffffff81477cff>] io_schedule_timeout+0xb7/0x12b [84723.245942] [<ffffffff81477cff>] ? io_schedule_timeout+0xb7/0x12b [84723.246596] [<ffffffff81478953>] bit_wait_io+0x39/0x45 [84723.247503] [<ffffffff81478b93>] __wait_on_bit_lock+0x49/0x8d [84723.248540] [<ffffffff8111684f>] __lock_page+0x66/0x68 [84723.249558] [<ffffffff81081c9b>] ? autoremove_wake_function+0x3a/0x3a [84723.250844] [<ffffffff81124a04>] lock_page+0x2c/0x2f [84723.251871] [<ffffffff81124afc>] invalidate_inode_pages2_range+0xf5/0x2aa [84723.253274] [<ffffffff81117c34>] ? filemap_fdatawait_range+0x12d/0x146 [84723.254757] [<ffffffff81118191>] ? filemap_fdatawrite_range+0x13/0x15 [84723.256378] [<ffffffffa05139a2>] btrfs_get_blocks_direct+0x1b0/0x664 [btrfs] [84723.258556] [<ffffffff8119e3f9>] ? submit_page_section+0x7b/0x111 [84723.260064] [<ffffffff8119eb90>] do_blockdev_direct_IO+0x658/0xbdb [84723.261479] [<ffffffffa05137f2>] ? btrfs_page_exists_in_range+0x1a9/0x1a9 [btrfs] [84723.262961] [<ffffffffa050a8a6>] ? btrfs_writepage_start_hook+0xce/0xce [btrfs] [84723.264449] [<ffffffff8119f144>] __blockdev_direct_IO+0x31/0x33 [84723.265614] [<ffffffff8119f144>] ? __blockdev_direct_IO+0x31/0x33 [84723.266769] [<ffffffffa050a8a6>] ? btrfs_writepage_start_hook+0xce/0xce [btrfs] [84723.268264] [<ffffffffa050935d>] btrfs_direct_IO+0x1b9/0x259 [btrfs] [84723.270954] [<ffffffffa050a8a6>] ? btrfs_writepage_start_hook+0xce/0xce [btrfs] [84723.272465] [<ffffffff8111878c>] generic_file_direct_write+0xb3/0x128 [84723.273734] [<ffffffffa051955c>] btrfs_file_write_iter+0x228/0x404 [btrfs] [84723.275101] [<ffffffff8116ca6f>] __vfs_write+0x7c/0xa5 [84723.276200] [<ffffffff8116cfab>] vfs_write+0xa0/0xe4 [84723.277298] [<ffffffff8116d79d>] SyS_write+0x50/0x7e [84723.278327] [<ffffffff8147cd97>] entry_SYSCALL_64_fastpath+0x12/0x6f [84723.279595] INFO: lockdep is turned off. [84723.379035] INFO: task btrfs:2923 blocked for more than 120 seconds. [84723.380323] Tainted: G W 4.3.0-rc5-btrfs-next-17+ #1 [84723.381608] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [84723.383003] btrfs D ffff88023ed75218 0 2923 2859 0x00000000 [84723.384277] ffff88001311f860 0000000000000082 ffff88001311f840 ffff88023ed75200 [84723.385748] ffff88012c6751c0 ffff880013120000 ffff88012042fe68 ffff88012042fe30 [84723.387152] ffff880221571c88 0000000000000001 ffff88001311f878 ffffffff8147856a [84723.388620] Call Trace: [84723.389105] [<ffffffff8147856a>] schedule+0x7d/0x95 [84723.391882] [<ffffffffa051da32>] btrfs_start_ordered_extent+0x161/0x1fa [btrfs] [84723.393718] [<ffffffff81081c61>] ? signal_pending_state+0x31/0x31 [84723.395659] [<ffffffffa0522c5b>] __do_contiguous_readpages.constprop.21+0x81/0xdc [btrfs] [84723.397383] [<ffffffffa050ac96>] ? btrfs_submit_direct+0x3f0/0x3f0 [btrfs] [84723.398852] [<ffffffffa0522da3>] __extent_readpages.constprop.20+0xed/0x100 [btrfs] [84723.400561] [<ffffffff81123f6c>] ? __lru_cache_add+0x5d/0x72 [84723.401787] [<ffffffffa0523896>] extent_readpages+0x111/0x1a7 [btrfs] [84723.403121] [<ffffffffa050ac96>] ? btrfs_submit_direct+0x3f0/0x3f0 [btrfs] [84723.404583] [<ffffffffa05088fa>] btrfs_readpages+0x1f/0x21 [btrfs] [84723.406007] [<ffffffff811226df>] __do_page_cache_readahead+0x168/0x1f4 [84723.407502] [<ffffffff81122988>] ondemand_readahead+0x21d/0x22e [84723.408937] [<ffffffff81122988>] ? ondemand_readahead+0x21d/0x22e [84723.410487] [<ffffffff81122af1>] page_cache_sync_readahead+0x3d/0x3f [84723.411710] [<ffffffffa0535388>] btrfs_defrag_file+0x419/0xaaf [btrfs] [84723.413007] [<ffffffffa0531db0>] ? kzalloc+0xf/0x11 [btrfs] [84723.414085] [<ffffffffa0535b43>] btrfs_ioctl_defrag+0x125/0x14e [btrfs] [84723.415307] [<ffffffffa0536753>] btrfs_ioctl+0x746/0x24c6 [btrfs] [84723.416532] [<ffffffff81087481>] ? arch_local_irq_save+0x9/0xc [84723.417731] [<ffffffff8113ad61>] ? __might_fault+0x4c/0xa7 [84723.418699] [<ffffffff8113ad61>] ? __might_fault+0x4c/0xa7 [84723.421532] [<ffffffff8113adba>] ? __might_fault+0xa5/0xa7 [84723.422629] [<ffffffff81171139>] ? cp_new_stat+0x15d/0x174 [84723.423712] [<ffffffff8117c610>] do_vfs_ioctl+0x427/0x4e6 [84723.424801] [<ffffffff81171175>] ? SYSC_newfstat+0x25/0x2e [84723.425968] [<ffffffff8118574d>] ? __fget_light+0x4d/0x71 [84723.427063] [<ffffffff8117c726>] SyS_ioctl+0x57/0x79 [84723.428138] [<ffffffff8147cd97>] entry_SYSCALL_64_fastpath+0x12/0x6f Consider the following logical and physical file layout: logical: ... [ prealloc extent A ] [ prealloc extent B ] [ extent C ] ... 4K 8K 16K physical: ... 12853248 12857344 1103101952 ... (= 12853248 + 4K) Extents A and B are physically adjacent. The following diagram shows a sequence of events that lead to the deadlock when we attempt to do a direct IO write against the file range [4K, 16K[ and a defrag is triggered simultaneously. CPU 1 CPU 2 btrfs_direct_IO() btrfs_get_blocks_direct() creates ordered extent A, covering the 4k prealloc extent A (range [4K, 8K[) btrfs_defrag_file() page_cache_sync_readahead([0K, 1M[) btrfs_readpages() extent_readpages() locks all pages in the file range [0K, 128K[ through calls to add_to_page_cache_lru() __do_contiguous_readpages() finds ordered extent A waits for it to complete btrfs_get_blocks_direct() called again lock_extent_direct(range [8K, 16K[) finds a page in range [8K, 16K[ through btrfs_page_exists_in_range() invalidate_inode_pages2_range([8K, 16K[) --> tries to lock pages that are already locked by the task at CPU 2 --> our task, running __blockdev_direct_IO(), hangs waiting to lock the pages and the submit bio callback, btrfs_submit_direct(), ends up never being called, resulting in the ordered extent A never completing (because a corresponding bio is never submitted) and CPU 2 will wait for it forever while holding the pages locked ---> deadlock! Fix this by removing the page invalidation approach when attempting to lock the range for IO from the callback btrfs_get_blocks_direct() and falling back buffered IO. This was a rare case anyway and well behaved applications do not mix concurrent direct IO writes with buffered reads anyway, being a concurrent defrag the only normal case that could lead to the deadlock. Signed-off-by: NFilipe Manana <fdmanana@suse.com> -
由 Filipe Manana 提交于
Commit 61de718f ("Btrfs: fix memory corruption on failure to submit bio for direct IO") fixed problems with the error handling code after we fail to submit a bio for direct IO. However there were 2 problems that it did not address when the failure is due to memory allocation failures for direct IO writes: 1) We considered that there could be only one ordered extent for the whole IO range, which is not always true, as we can have multiple; 2) It did not set the bit BTRFS_ORDERED_IO_DONE in the ordered extent, which can make other tasks running btrfs_wait_logged_extents() hang forever, since they wait for that bit to be set. The general assumption is that regardless of an error, the BTRFS_ORDERED_IO_DONE is always set and it precedes setting the bit BTRFS_ORDERED_COMPLETE. Fix these issues by moving part of the btrfs_endio_direct_write() handler into a new helper function and having that new helper function called when we fail to allocate memory to submit the bio (and its private object) for a direct IO write. Signed-off-by: NFilipe Manana <fdmanana@suse.com> Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
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- 09 12月, 2015 2 次提交
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由 Al Viro 提交于
new method: ->get_link(); replacement of ->follow_link(). The differences are: * inode and dentry are passed separately * might be called both in RCU and non-RCU mode; the former is indicated by passing it a NULL dentry. * when called that way it isn't allowed to block and should return ERR_PTR(-ECHILD) if it needs to be called in non-RCU mode. It's a flagday change - the old method is gone, all in-tree instances converted. Conversion isn't hard; said that, so far very few instances do not immediately bail out when called in RCU mode. That'll change in the next commits. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk> -
由 Al Viro 提交于
kmap() in page_follow_link_light() needed to go - allowing to hold an arbitrary number of kmaps for long is a great way to deadlocking the system. new helper (inode_nohighmem(inode)) needs to be used for pagecache symlinks inodes; done for all in-tree cases. page_follow_link_light() instrumented to yell about anything missed. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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