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2016-02-11btrfs: introduce key type for persistent permanent itemsDavid Sterba
The number of distinct key types is not that big that we could waste one for something new we want to store in the tree. Similar to the temporary items, we'll introduce a new name for an existing key value and use the objectid for further extension. The victim is the BTRFS_DEV_STATS_KEY (248). The device stats are an example of a permanent item. Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-11btrfs: switch balance item to the temporary item keyDavid Sterba
No visible change. Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-11btrfs: introduce key type for persistent temporary itemsDavid Sterba
The number of distinct key types is not that big that we could waste one for something new we want to store in the tree. We'll introduce a new name for an existing key value and use the objectid for further extension. The victim is the BTRFS_BALANCE_ITEM_KEY (248). The nature of the balance status item is a good example of the temporary item. It exists from beginning of the balance, keeps the status until it finishes. Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-11btrfs: properly set the termination value of ctx->pos in readdirDavid Sterba
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=4284 Reported-by: Victor <services@swwu.com> CC: stable@vger.kernel.org Signed-off-by: David Sterba <dsterba@suse.com> Tested-by: Holger Hoffstätte <holger.hoffstaette@googlemail.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-11btrfs: switch to kcalloc in btrfs_cmp_data_prepareDavid Sterba
Kcalloc is functionally equivalent and does overflow checks. Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-11btrfs: extent same: use GFP_KERNEL for page array allocationsDavid Sterba
We can safely use GFP_KERNEL in the functions called from the ioctl handlers. Here we can allocate up to 32k so less pressure to the allocator could help. Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-11btrfs: device add and remove: use GFP_KERNELDavid Sterba
We can safely use GFP_KERNEL in the functions called from the ioctl handlers. Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-11btrfs: readdir: use GFP_KERNELDavid Sterba
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: David Sterba <dsterba@suse.com>
2016-02-11btrfs: fallocate: use GFP_KERNELDavid Sterba
Fallocate 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: David Sterba <dsterba@suse.com>
2016-02-11btrfs: let callers of btrfs_alloc_root pass gfp flagsDavid Sterba
We don't need to use GFP_NOFS in all contexts, eg. during mount or for dummy root tree, but we might for the the log tree creation. Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-11btrfs: scrub: use GFP_KERNEL on the submission pathDavid Sterba
Scrub is not on the critical writeback path we don't need to use GFP_NOFS for all allocations. The failures are handled and stats passed back to userspace. Let's use GFP_KERNEL on the paths where everything is ok, ie. setup the global structures and the IO submission paths. Functions that do the repair and fixups still use GFP_NOFS as we might want to skip any other filesystem activity if we encounter an error. This could turn out to be unnecessary, but requires more review compared to the easy cases in this patch. Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-11btrfs: reada: use GFP_KERNEL everywhereDavid Sterba
The readahead framework is not on the critical writeback path we don't need to use GFP_NOFS for allocations. All error paths are handled and the readahead failures are not fatal. The actual users (scrub, dev-replace) will trigger reads if the blocks are not found in cache. Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-11btrfs: send: use GFP_KERNEL everywhereDavid Sterba
The send operation is not on the critical writeback path we don't need to use GFP_NOFS for allocations. All error paths are handled and the whole operation is restartable. Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-05Btrfs: fix hang on extent buffer lock caused by the inode_paths ioctlFilipe Manana
While doing some tests I ran into an hang on an extent buffer's rwlock that produced the following trace: [39389.800012] NMI watchdog: BUG: soft lockup - CPU#15 stuck for 22s! [fdm-stress:32166] [39389.800016] NMI watchdog: BUG: soft lockup - CPU#14 stuck for 22s! [fdm-stress:32165] [39389.800016] Modules linked in: btrfs dm_mod ppdev xor sha256_generic hmac raid6_pq drbg ansi_cprng aesni_intel i2c_piix4 acpi_cpufreq aes_x86_64 ablk_helper tpm_tis parport_pc i2c_core sg cryptd evdev psmouse lrw tpm parport gf128mul serio_raw pcspkr glue_helper processor button loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel scsi_mod e1000 virtio floppy [last unloaded: btrfs] [39389.800016] irq event stamp: 0 [39389.800016] hardirqs last enabled at (0): [< (null)>] (null) [39389.800016] hardirqs last disabled at (0): [<ffffffff8104e58d>] copy_process+0x638/0x1a35 [39389.800016] softirqs last enabled at (0): [<ffffffff8104e58d>] copy_process+0x638/0x1a35 [39389.800016] softirqs last disabled at (0): [< (null)>] (null) [39389.800016] CPU: 14 PID: 32165 Comm: fdm-stress Not tainted 4.4.0-rc6-btrfs-next-18+ #1 [39389.800016] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [39389.800016] task: ffff880175b1ca40 ti: ffff8800a185c000 task.ti: ffff8800a185c000 [39389.800016] RIP: 0010:[<ffffffff810902af>] [<ffffffff810902af>] queued_spin_lock_slowpath+0x57/0x158 [39389.800016] RSP: 0018:ffff8800a185fb80 EFLAGS: 00000202 [39389.800016] RAX: 0000000000000101 RBX: ffff8801710c4e9c RCX: 0000000000000101 [39389.800016] RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000001 [39389.800016] RBP: ffff8800a185fb98 R08: 0000000000000001 R09: 0000000000000000 [39389.800016] R10: ffff8800a185fb68 R11: 6db6db6db6db6db7 R12: ffff8801710c4e98 [39389.800016] R13: ffff880175b1ca40 R14: ffff8800a185fc10 R15: ffff880175b1ca40 [39389.800016] FS: 00007f6d37fff700(0000) GS:ffff8802be9c0000(0000) knlGS:0000000000000000 [39389.800016] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [39389.800016] CR2: 00007f6d300019b8 CR3: 0000000037c93000 CR4: 00000000001406e0 [39389.800016] Stack: [39389.800016] ffff8801710c4e98 ffff8801710c4e98 ffff880175b1ca40 ffff8800a185fbb0 [39389.800016] ffffffff81091e11 ffff8801710c4e98 ffff8800a185fbc8 ffffffff81091895 [39389.800016] ffff8801710c4e98 ffff8800a185fbe8 ffffffff81486c5c ffffffffa067288c [39389.800016] Call Trace: [39389.800016] [<ffffffff81091e11>] queued_read_lock_slowpath+0x46/0x60 [39389.800016] [<ffffffff81091895>] do_raw_read_lock+0x3e/0x41 [39389.800016] [<ffffffff81486c5c>] _raw_read_lock+0x3d/0x44 [39389.800016] [<ffffffffa067288c>] ? btrfs_tree_read_lock+0x54/0x125 [btrfs] [39389.800016] [<ffffffffa067288c>] btrfs_tree_read_lock+0x54/0x125 [btrfs] [39389.800016] [<ffffffffa0622ced>] ? btrfs_find_item+0xa7/0xd2 [btrfs] [39389.800016] [<ffffffffa069363f>] btrfs_ref_to_path+0xd6/0x174 [btrfs] [39389.800016] [<ffffffffa0693730>] inode_to_path+0x53/0xa2 [btrfs] [39389.800016] [<ffffffffa0693e2e>] paths_from_inode+0x117/0x2ec [btrfs] [39389.800016] [<ffffffffa0670cff>] btrfs_ioctl+0xd5b/0x2793 [btrfs] [39389.800016] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [39389.800016] [<ffffffff81276727>] ? __this_cpu_preempt_check+0x13/0x15 [39389.800016] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [39389.800016] [<ffffffff8118b3d4>] ? rcu_read_unlock+0x3e/0x5d [39389.800016] [<ffffffff811822f8>] do_vfs_ioctl+0x42b/0x4ea [39389.800016] [<ffffffff8118b4f3>] ? __fget_light+0x62/0x71 [39389.800016] [<ffffffff8118240e>] SyS_ioctl+0x57/0x79 [39389.800016] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [39389.800016] Code: b9 01 01 00 00 f7 c6 00 ff ff ff 75 32 83 fe 01 89 ca 89 f0 0f 45 d7 f0 0f b1 13 39 f0 74 04 89 c6 eb e2 ff ca 0f 84 fa 00 00 00 <8b> 03 84 c0 74 04 f3 90 eb f6 66 c7 03 01 00 e9 e6 00 00 00 e8 [39389.800012] Modules linked in: btrfs dm_mod ppdev xor sha256_generic hmac raid6_pq drbg ansi_cprng aesni_intel i2c_piix4 acpi_cpufreq aes_x86_64 ablk_helper tpm_tis parport_pc i2c_core sg cryptd evdev psmouse lrw tpm parport gf128mul serio_raw pcspkr glue_helper processor button loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel scsi_mod e1000 virtio floppy [last unloaded: btrfs] [39389.800012] irq event stamp: 0 [39389.800012] hardirqs last enabled at (0): [< (null)>] (null) [39389.800012] hardirqs last disabled at (0): [<ffffffff8104e58d>] copy_process+0x638/0x1a35 [39389.800012] softirqs last enabled at (0): [<ffffffff8104e58d>] copy_process+0x638/0x1a35 [39389.800012] softirqs last disabled at (0): [< (null)>] (null) [39389.800012] CPU: 15 PID: 32166 Comm: fdm-stress Tainted: G L 4.4.0-rc6-btrfs-next-18+ #1 [39389.800012] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [39389.800012] task: ffff880179294380 ti: ffff880034a60000 task.ti: ffff880034a60000 [39389.800012] RIP: 0010:[<ffffffff81091e8d>] [<ffffffff81091e8d>] queued_write_lock_slowpath+0x62/0x72 [39389.800012] RSP: 0018:ffff880034a639f0 EFLAGS: 00000206 [39389.800012] RAX: 0000000000000101 RBX: ffff8801710c4e98 RCX: 0000000000000000 [39389.800012] RDX: 00000000000000ff RSI: 0000000000000000 RDI: ffff8801710c4e9c [39389.800012] RBP: ffff880034a639f8 R08: 0000000000000001 R09: 0000000000000000 [39389.800012] R10: ffff880034a639b0 R11: 0000000000001000 R12: ffff8801710c4e98 [39389.800012] R13: 0000000000000001 R14: ffff880172cbc000 R15: ffff8801710c4e00 [39389.800012] FS: 00007f6d377fe700(0000) GS:ffff8802be9e0000(0000) knlGS:0000000000000000 [39389.800012] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [39389.800012] CR2: 00007f6d3d3c1000 CR3: 0000000037c93000 CR4: 00000000001406e0 [39389.800012] Stack: [39389.800012] ffff8801710c4e98 ffff880034a63a10 ffffffff81091963 ffff8801710c4e98 [39389.800012] ffff880034a63a30 ffffffff81486f1b ffffffffa0672cb3 ffff8801710c4e00 [39389.800012] ffff880034a63a78 ffffffffa0672cb3 ffff8801710c4e00 ffff880034a63a58 [39389.800012] Call Trace: [39389.800012] [<ffffffff81091963>] do_raw_write_lock+0x72/0x8c [39389.800012] [<ffffffff81486f1b>] _raw_write_lock+0x3a/0x41 [39389.800012] [<ffffffffa0672cb3>] ? btrfs_tree_lock+0x119/0x251 [btrfs] [39389.800012] [<ffffffffa0672cb3>] btrfs_tree_lock+0x119/0x251 [btrfs] [39389.800012] [<ffffffffa061aeba>] ? rcu_read_unlock+0x5b/0x5d [btrfs] [39389.800012] [<ffffffffa061ce13>] ? btrfs_root_node+0xda/0xe6 [btrfs] [39389.800012] [<ffffffffa061ce83>] btrfs_lock_root_node+0x22/0x42 [btrfs] [39389.800012] [<ffffffffa062046b>] btrfs_search_slot+0x1b8/0x758 [btrfs] [39389.800012] [<ffffffff810fc6b0>] ? time_hardirqs_on+0x15/0x28 [39389.800012] [<ffffffffa06365db>] btrfs_lookup_inode+0x31/0x95 [btrfs] [39389.800012] [<ffffffff8108d62f>] ? trace_hardirqs_on+0xd/0xf [39389.800012] [<ffffffff8148482b>] ? mutex_lock_nested+0x397/0x3bc [39389.800012] [<ffffffffa068821b>] __btrfs_update_delayed_inode+0x59/0x1c0 [btrfs] [39389.800012] [<ffffffffa068858e>] __btrfs_commit_inode_delayed_items+0x194/0x5aa [btrfs] [39389.800012] [<ffffffff81486ab7>] ? _raw_spin_unlock+0x31/0x44 [39389.800012] [<ffffffffa0688a48>] __btrfs_run_delayed_items+0xa4/0x15c [btrfs] [39389.800012] [<ffffffffa0688d62>] btrfs_run_delayed_items+0x11/0x13 [btrfs] [39389.800012] [<ffffffffa064048e>] btrfs_commit_transaction+0x234/0x96e [btrfs] [39389.800012] [<ffffffffa0618d10>] btrfs_sync_fs+0x145/0x1ad [btrfs] [39389.800012] [<ffffffffa0671176>] btrfs_ioctl+0x11d2/0x2793 [btrfs] [39389.800012] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [39389.800012] [<ffffffff81140261>] ? __might_fault+0x4c/0xa7 [39389.800012] [<ffffffff81140261>] ? __might_fault+0x4c/0xa7 [39389.800012] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [39389.800012] [<ffffffff8118b3d4>] ? rcu_read_unlock+0x3e/0x5d [39389.800012] [<ffffffff811822f8>] do_vfs_ioctl+0x42b/0x4ea [39389.800012] [<ffffffff8118b4f3>] ? __fget_light+0x62/0x71 [39389.800012] [<ffffffff8118240e>] SyS_ioctl+0x57/0x79 [39389.800012] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [39389.800012] Code: f0 0f b1 13 85 c0 75 ef eb 2a f3 90 8a 03 84 c0 75 f8 f0 0f b0 13 84 c0 75 f0 ba ff 00 00 00 eb 0a f0 0f b1 13 ff c8 74 0b f3 90 <8b> 03 83 f8 01 75 f7 eb ed c6 43 04 00 5b 5d c3 0f 1f 44 00 00 This happens because in the code path executed by the inode_paths ioctl we end up nesting two calls to read lock a leaf's rwlock when after the first call to read_lock() and before the second call to read_lock(), another task (running the delayed items as part of a transaction commit) has already called write_lock() against the leaf's rwlock. This situation is illustrated by the following diagram: Task A Task B btrfs_ref_to_path() btrfs_commit_transaction() read_lock(&eb->lock); btrfs_run_delayed_items() __btrfs_commit_inode_delayed_items() __btrfs_update_delayed_inode() btrfs_lookup_inode() write_lock(&eb->lock); --> task waits for lock read_lock(&eb->lock); --> makes this task hang forever (and task B too of course) So fix this by avoiding doing the nested read lock, which is easily avoidable. This issue does not happen if task B calls write_lock() after task A does the second call to read_lock(), however there does not seem to exist anything in the documentation that mentions what is the expected behaviour for recursive locking of rwlocks (leaving the idea that doing so is not a good usage of rwlocks). Also, as a side effect necessary for this fix, make sure we do not needlessly read lock extent buffers when the input path has skip_locking set (used when called from send). Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-02-03Btrfs: remove no longer used function extent_read_full_page_nolock()Filipe Manana
Not needed after the previous patch named "Btrfs: fix page reading in extent_same ioctl leading to csum errors". Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-02-03Btrfs: fix page reading in extent_same ioctl leading to csum errorsFilipe Manana
In the extent_same ioctl, we were grabbing the pages (locked) and attempting to read them without bothering about any concurrent IO against them. That is, we were not checking for any ongoing ordered extents nor waiting for them to complete, which leads to a race where the extent_same() code gets a checksum verification error when it reads the pages, producing a message like the following in dmesg and making the operation fail to user space with -ENOMEM: [18990.161265] BTRFS warning (device sdc): csum failed ino 259 off 495616 csum 685204116 expected csum 1515870868 Fix this by using btrfs_readpage() for reading the pages instead of extent_read_full_page_nolock(), which waits for any concurrent ordered extents to complete and locks the io range. Also do better error handling and don't treat all failures as -ENOMEM, as that's clearly misleasing, becoming identical to the checks and operation of prepare_uptodate_page(). The use of extent_read_full_page_nolock() was required before commit f441460202cb ("btrfs: fix deadlock with extent-same and readpage"), as we had the range locked in an inode's io tree before attempting to read the pages. Fixes: f441460202cb ("btrfs: fix deadlock with extent-same and readpage") Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-02-03Btrfs: fix invalid page accesses in extent_same (dedup) ioctlFilipe Manana
In the extent_same ioctl we are getting the pages for the source and target ranges and unlocking them immediately after, which is incorrect because later we attempt to map them (with kmap_atomic) and access their contents at btrfs_cmp_data(). When we do such access the pages might have been relocated or removed from memory, which leads to an invalid memory access. This issue is detected on a kernel with CONFIG_DEBUG_PAGEALLOC=y which produces a trace like the following: 186736.677437] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [186736.680382] Modules linked in: btrfs dm_flakey dm_mod ppdev xor raid6_pq sha256_generic hmac drbg ansi_cprng acpi_cpufreq evdev sg aesni_intel aes_x86_64 parport_pc ablk_helper tpm_tis psmouse parport i2c_piix4 tpm cryptd i2c_core lrw processor button serio_raw pcspkr gf128mul glue_helper loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel scsi_mod e1000 virtio floppy [last unloaded: btrfs] [186736.681319] CPU: 13 PID: 10222 Comm: duperemove Tainted: G W 4.4.0-rc6-btrfs-next-18+ #1 [186736.681319] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [186736.681319] task: ffff880132600400 ti: ffff880362284000 task.ti: ffff880362284000 [186736.681319] RIP: 0010:[<ffffffff81264d00>] [<ffffffff81264d00>] memcmp+0xb/0x22 [186736.681319] RSP: 0018:ffff880362287d70 EFLAGS: 00010287 [186736.681319] RAX: 000002c002468acf RBX: 0000000012345678 RCX: 0000000000000000 [186736.681319] RDX: 0000000000001000 RSI: 0005d129c5cf9000 RDI: 0005d129c5cf9000 [186736.681319] RBP: ffff880362287d70 R08: 0000000000000000 R09: 0000000000001000 [186736.681319] R10: ffff880000000000 R11: 0000000000000476 R12: 0000000000001000 [186736.681319] R13: ffff8802f91d4c88 R14: ffff8801f2a77830 R15: ffff880352e83e40 [186736.681319] FS: 00007f27b37fe700(0000) GS:ffff88043dda0000(0000) knlGS:0000000000000000 [186736.681319] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [186736.681319] CR2: 00007f27a406a000 CR3: 0000000217421000 CR4: 00000000001406e0 [186736.681319] Stack: [186736.681319] ffff880362287ea0 ffffffffa048d0bd 000000000009f000 0000000000001000 [186736.681319] 0100000000000000 ffff8801f2a77850 ffff8802f91d49b0 ffff880132600400 [186736.681319] 00000000000004f8 ffff8801c1efbe41 0000000000000000 0000000000000038 [186736.681319] Call Trace: [186736.681319] [<ffffffffa048d0bd>] btrfs_ioctl+0x24cb/0x2731 [btrfs] [186736.681319] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [186736.681319] [<ffffffff8118b3d4>] ? rcu_read_unlock+0x3e/0x5d [186736.681319] [<ffffffff811822f8>] do_vfs_ioctl+0x42b/0x4ea [186736.681319] [<ffffffff8118b4f3>] ? __fget_light+0x62/0x71 [186736.681319] [<ffffffff8118240e>] SyS_ioctl+0x57/0x79 [186736.681319] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [186736.681319] Code: 0a 3c 6e 74 0d 3c 79 74 04 3c 59 75 0c c6 06 01 eb 03 c6 06 00 31 c0 eb 05 b8 ea ff ff ff 5d c3 55 31 c9 48 89 e5 48 39 d1 74 13 <0f> b6 04 0f 44 0f b6 04 0e 48 ff c1 44 29 c0 74 ea eb 02 31 c0 (gdb) list *(btrfs_ioctl+0x24cb) 0x5e0e1 is in btrfs_ioctl (fs/btrfs/ioctl.c:2972). 2967 dst_addr = kmap_atomic(dst_page); 2968 2969 flush_dcache_page(src_page); 2970 flush_dcache_page(dst_page); 2971 2972 if (memcmp(addr, dst_addr, cmp_len)) 2973 ret = BTRFS_SAME_DATA_DIFFERS; 2974 2975 kunmap_atomic(addr); 2976 kunmap_atomic(dst_addr); So fix this by making sure we keep the pages locked and respect the same locking order as everywhere else: get and lock the pages first and then lock the range in the inode's io tree (like for example at __btrfs_buffered_write() and extent_readpages()). If an ordered extent is found after locking the range in the io tree, unlock the range, unlock the pages, wait for the ordered extent to complete and repeat the entire locking process until no overlapping ordered extents are found. Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-02-01Btrfs: btrfs_ioctl_clone: Truncate complete page after performing clone ↵Chandan Rajendra
operation In subpagesize-blocksize scenario, the "destination offset" argument passed to the btrfs_ioctl_clone() can be aligned to sectorsize but may not be necessarily aligned to the machine's page size. In such cases, truncate_inode_pages_range() ends up zeroing out the partial page and future read operations will return incorrect data. Hence this commit explicitly rounds down the "destination offset" to the machine's page size. Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-01Btrfs: Clean pte corresponding to page straddling i_sizeChandan Rajendra
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: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-01Btrfs: Fix block size returned to user spaceChandan Rajendra
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: Josef Bacik <jbacik@fb.com> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-01Btrfs: Limit inline extents to root->sectorsizeChandan Rajendra
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: Josef Bacik <jbacik@fb.com> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-01Btrfs: btrfs_submit_direct_hook: Handle map_length < bio vector lengthChandan Rajendra
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: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-01Btrfs: Use (eb->start, seq) as search key for tree modification logChandan Rajendra
In subpagesize-blocksize a page can map multiple extent buffers and hence using (page index, seq) as the search key is incorrect. For example, searching through tree modification log tree can return an entry associated with the first extent buffer mapped by the page (if such an entry exists), when we are actually searching for entries associated with extent buffers that are mapped at position 2 or more in the page. Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-01Btrfs: Search for all ordered extents that could span across a pageChandan Rajendra
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: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-01Btrfs: btrfs_page_mkwrite: Reserve space in sectorsized unitsChandan Rajendra
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: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-01Btrfs: fallocate: Work with sectorsized blocksChandan Rajendra
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: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-01Btrfs: Direct I/O read: Work on sectorsized blocksChandan Rajendra
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: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-01Btrfs: Compute and look up csums based on sectorsized blocksChandan Rajendra
Checksums are applicable to sectorsize units. The current code uses bio->bv_len units to compute and look up checksums. This works on machines where sectorsize == PAGE_SIZE. This patch makes the checksum computation and look up code to work with sectorsize units. Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-01Btrfs: __btrfs_buffered_write: Reserve/release extents aligned to block sizeChandan Rajendra
Currently, the code reserves/releases extents in multiples of PAGE_CACHE_SIZE units. Fix this by doing reservation/releases in block size units. Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-30x86/cpufeature: Replace the old static_cpu_has() with safe variantBorislav Petkov
So the old one didn't work properly before alternatives had run. And it was supposed to provide an optimized JMP because the assumption was that the offset it is jumping to is within a signed byte and thus a two-byte JMP. So I did an x86_64 allyesconfig build and dumped all possible sites where static_cpu_has() was used. The optimization amounted to all in all 12(!) places where static_cpu_has() had generated a 2-byte JMP. Which has saved us a whopping 36 bytes! This clearly is not worth the trouble so we can remove it. The only place where the optimization might count - in __switch_to() - we will handle differently. But that's not subject of this patch. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1453842730-28463-6-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29Merge branch 'for-linus-4.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "Dave had a small collection of fixes to the new free space tree code, one of which was keeping our sysfs files more up to date with feature bits as different things get enabled (lzo, raid5/6, etc). I should have kept the sysfs stuff for rc3, since we always manage to trip over something. This time it was GFP_KERNEL from somewhere that is NOFS only. Instead of rebasing it out I've put a revert in, and we'll fix it properly for rc3. Otherwise, Filipe fixed a btrfs DIO race and Qu Wenruo fixed up a use-after-free in our tracepoints that Dave Jones reported" * 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Revert "btrfs: synchronize incompat feature bits with sysfs files" btrfs: don't use GFP_HIGHMEM for free-space-tree bitmap kzalloc btrfs: sysfs: check initialization state before updating features Revert "btrfs: clear PF_NOFREEZE in cleaner_kthread()" btrfs: async-thread: Fix a use-after-free error for trace Btrfs: fix race between fsync and lockless direct IO writes btrfs: add free space tree to the cow-only list btrfs: add free space tree to lockdep classes btrfs: tweak free space tree bitmap allocation btrfs: tests: switch to GFP_KERNEL btrfs: synchronize incompat feature bits with sysfs files btrfs: sysfs: introduce helper for syncing bits with sysfs files btrfs: sysfs: add free-space-tree bit attribute btrfs: sysfs: fix typo in compat_ro attribute definition
2016-01-29Revert "btrfs: synchronize incompat feature bits with sysfs files"Chris Mason
This reverts commit 14e46e04958df740c6c6a94849f176159a333f13. This ends up doing sysfs operations from deep in balance (where we should be GFP_NOFS) and under heavy balance load, we're making races against sysfs internals. Revert it for now while we figure things out. Signed-off-by: Chris Mason <clm@fb.com>
2016-01-27btrfs: don't use GFP_HIGHMEM for free-space-tree bitmap kzallocChris Mason
This was copied incorrectly from the __vmalloc call. Signed-off-by: Chris Mason <clm@fb.com>
2016-01-27Merge branch 'dev/fst-followup' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5
2016-01-27btrfs: sysfs: check initialization state before updating featuresDavid Sterba
If the mount phase is not finished, we can't update the sysfs files. Reported-by: Chris Mason <clm@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-01-25Revert "btrfs: clear PF_NOFREEZE in cleaner_kthread()"David Sterba
This reverts commit 696249132158014d594896df3a81390616069c5c. The cleaner thread can block freezing when there's a snapshot cleaning in progress and the other threads get suspended first. From the logs provided by Martin we're waiting for reading extent pages: kernel: PM: Syncing filesystems ... done. kernel: Freezing user space processes ... (elapsed 0.015 seconds) done. kernel: Freezing remaining freezable tasks ... kernel: Freezing of tasks failed after 20.003 seconds (1 tasks refusing to freeze, wq_busy=0): kernel: btrfs-cleaner D ffff88033dd13bc0 0 152 2 0x00000000 kernel: ffff88032ebc2e00 ffff88032e750000 ffff88032e74fa50 7fffffffffffffff kernel: ffffffff814a58df 0000000000000002 ffffea000934d580 ffffffff814a5451 kernel: 7fffffffffffffff ffffffff814a6e8f 0000000000000000 0000000000000020 kernel: Call Trace: kernel: [<ffffffff814a58df>] ? bit_wait+0x2c/0x2c kernel: [<ffffffff814a5451>] ? schedule+0x6f/0x7c kernel: [<ffffffff814a6e8f>] ? schedule_timeout+0x2f/0xd8 kernel: [<ffffffff81076f94>] ? timekeeping_get_ns+0xa/0x2e kernel: [<ffffffff81077603>] ? ktime_get+0x36/0x44 kernel: [<ffffffff814a4f6c>] ? io_schedule_timeout+0x94/0xf2 kernel: [<ffffffff814a4f6c>] ? io_schedule_timeout+0x94/0xf2 kernel: [<ffffffff814a590b>] ? bit_wait_io+0x2c/0x30 kernel: [<ffffffff814a5694>] ? __wait_on_bit+0x41/0x73 kernel: [<ffffffff8109eba8>] ? wait_on_page_bit+0x6d/0x72 kernel: [<ffffffff8105d718>] ? autoremove_wake_function+0x2a/0x2a kernel: [<ffffffff811a02d7>] ? read_extent_buffer_pages+0x1bd/0x203 kernel: [<ffffffff8117d9e9>] ? free_root_pointers+0x4c/0x4c kernel: [<ffffffff8117e831>] ? btree_read_extent_buffer_pages.constprop.57+0x5a/0xe9 kernel: [<ffffffff8117f4f3>] ? read_tree_block+0x2d/0x45 kernel: [<ffffffff8116782a>] ? read_block_for_search.isra.34+0x22a/0x26b kernel: [<ffffffff811656c3>] ? btrfs_set_path_blocking+0x1e/0x4a kernel: [<ffffffff8116919b>] ? btrfs_search_slot+0x648/0x736 kernel: [<ffffffff81170559>] ? btrfs_lookup_extent_info+0xb7/0x2c7 kernel: [<ffffffff81170ee5>] ? walk_down_proc+0x9c/0x1ae kernel: [<ffffffff81171c9d>] ? walk_down_tree+0x40/0xa4 kernel: [<ffffffff8117375f>] ? btrfs_drop_snapshot+0x2da/0x664 kernel: [<ffffffff8104ff21>] ? finish_task_switch+0x126/0x167 kernel: [<ffffffff811850f8>] ? btrfs_clean_one_deleted_snapshot+0xa6/0xb0 kernel: [<ffffffff8117eaba>] ? cleaner_kthread+0x13e/0x17b kernel: [<ffffffff8117e97c>] ? btrfs_item_end+0x33/0x33 kernel: [<ffffffff8104d256>] ? kthread+0x95/0x9d kernel: [<ffffffff8104d1c1>] ? kthread_parkme+0x16/0x16 kernel: [<ffffffff814a7b5f>] ? ret_from_fork+0x3f/0x70 kernel: [<ffffffff8104d1c1>] ? kthread_parkme+0x16/0x16 As this affects a released kernel (4.4) we need a minimal fix for stable kernels. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=108361 Reported-by: Martin Ziegler <ziegler@uni-freiburg.de> CC: stable@vger.kernel.org # 4.4 CC: Jiri Kosina <jkosina@suse.cz> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-01-25btrfs: async-thread: Fix a use-after-free error for traceQu Wenruo
Parameter of trace_btrfs_work_queued() can be freed in its workqueue. So no one use use that pointer after queue_work(). Fix the user-after-free bug by move the trace line before queue_work(). Reported-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-01-25Btrfs: fix race between fsync and lockless direct IO writesFilipe Manana
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: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-01-25Merge branch 'fix/fst-sysfs' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5 Signed-off-by: Chris Mason <clm@fb.com>
2016-01-25btrfs: add free space tree to the cow-only listDavid Sterba
Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-25btrfs: add free space tree to lockdep classesDavid Sterba
Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-22wrappers for ->i_mutex accessAl Viro
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: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22Merge branch 'for-linus-4.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull more btrfs updates from Chris Mason: "These are mostly fixes that we've been testing, but also we grabbed and tested a few small cleanups that had been on the list for a while. Zhao Lei's patchset also fixes some early ENOSPC buglets" * 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (21 commits) btrfs: raid56: Use raid_write_end_io for scrub btrfs: Remove unnecessary ClearPageUptodate for raid56 btrfs: use rbio->nr_pages to reduce calculation btrfs: Use unified stripe_page's index calculation btrfs: Fix calculation of rbio->dbitmap's size calculation btrfs: Fix no_space in write and rm loop btrfs: merge functions for wait snapshot creation btrfs: delete unused argument in btrfs_copy_from_user btrfs: Use direct way to determine raid56 write/recover mode btrfs: Small cleanup for get index_srcdev loop btrfs: Enhance chunk validation check btrfs: Enhance super validation check Btrfs: fix deadlock running delayed iputs at transaction commit time Btrfs: fix typo in log message when starting a balance btrfs: remove duplicate const specifier btrfs: initialize the seq counter in struct btrfs_device Btrfs: clean up an error code in btrfs_init_space_info() btrfs: fix iterator with update error in backref.c Btrfs: fix output of compression message in btrfs_parse_options() Btrfs: Initialize btrfs_root->highest_objectid when loading tree root and subvolume roots ...
2016-01-22btrfs: tweak free space tree bitmap allocationDavid Sterba
The requested bitmap size varies, observed numbers were < 4K up to 16K. Using vmalloc unconditionally would be too heavy, we'll try contiguous allocations first and fall back to vmalloc if there's no contig memory. Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-22btrfs: tests: switch to GFP_KERNELDavid Sterba
There's no reason to do GFP_NOFS in tests, it's not data-heavy and memory allocation failures would affect only developers or testers. Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-21btrfs: synchronize incompat feature bits with sysfs filesDavid Sterba
The files under /sys/fs/UUID/features get out of sync with the actual incompat bits set for the filesystem if they change after mount (eg. the LZO compression). Synchronize the feature bits with the sysfs files representing them right after we set/clear them. Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-21btrfs: sysfs: introduce helper for syncing bits with sysfs filesDavid Sterba
The files under /sys/fs/UUID/features get out of sync with the actual incompat bits set for the filesystem if they change after mount. We're going to sync them and need a helper to do that. Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-21btrfs: sysfs: add free-space-tree bit attributeDavid Sterba
The incompat bit representing the newly added free space tree feature is missing. Right now it will be listed only among features supported by the module, not per-fs. Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-20btrfs: sysfs: fix typo in compat_ro attribute definitionDavid Sterba
Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-20btrfs: raid56: Use raid_write_end_io for scrubZhao Lei
No need to create additional end_io function for scrub, it increased code size and introduced some un-unified lines, as: raid_write_parity_end_io(): int err = bio->bi_error; if (bio->bi_error) raid_write_end_io(): int err = bio->bi_error; if (err) This patch combines them. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>