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* mm: convert i_mmap_mutex to rwsemDavidlohr Bueso2014-12-132-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | The i_mmap_mutex is a close cousin of the anon vma lock, both protecting similar data, one for file backed pages and the other for anon memory. To this end, this lock can also be a rwsem. In addition, there are some important opportunities to share the lock when there are no tree modifications. This conversion is straightforward. For now, all users take the write lock. [sfr@canb.auug.org.au: update fremap.c] Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name> Acked-by: Hugh Dickins <hughd@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: use new helper functions around the i_mmap_mutexDavidlohr Bueso2014-12-131-2/+2
| | | | | | | | | | | | | | | | Convert all open coded mutex_lock/unlock calls to the i_mmap_[lock/unlock]_write() helpers. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name> Acked-by: Hugh Dickins <hughd@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'please-pull-morepstore' of ↵Linus Torvalds2014-12-122-11/+33
|\ | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux Pull pstore update #2 from Tony Luck: "Couple of pstore-ram enhancements to allow use of different memory attributes" * tag 'please-pull-morepstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux: pstore-ram: Allow optional mapping with pgprot_noncached pstore-ram: Fix hangs by using write-combine mappings
| * pstore-ram: Allow optional mapping with pgprot_noncachedTony Lindgren2014-12-112-11/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On some ARMs the memory can be mapped pgprot_noncached() and still be working for atomic operations. As pointed out by Colin Cross <ccross@android.com>, in some cases you do want to use pgprot_noncached() if the SoC supports it to see a debug printk just before a write hanging the system. On ARMs, the atomic operations on strongly ordered memory are implementation defined. So let's provide an optional kernel parameter for configuring pgprot_noncached(), and use pgprot_writecombine() by default. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rob Herring <robherring2@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Olof Johansson <olof@lixom.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: stable@vger.kernel.org Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
| * pstore-ram: Fix hangs by using write-combine mappingsRob Herring2014-12-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently trying to use pstore on at least ARMs can hang as we're mapping the peristent RAM with pgprot_noncached(). On ARMs, pgprot_noncached() will actually make the memory strongly ordered, and as the atomic operations pstore uses are implementation defined for strongly ordered memory, they may not work. So basically atomic operations have undefined behavior on ARM for device or strongly ordered memory types. Let's fix the issue by using write-combine variants for mappings. This corresponds to normal, non-cacheable memory on ARM. For many other architectures, this change does not change the mapping type as by default we have: #define pgprot_writecombine pgprot_noncached The reason why pgprot_noncached() was originaly used for pstore is because Colin Cross <ccross@android.com> had observed lost debug prints right before a device hanging write operation on some systems. For the platforms supporting pgprot_noncached(), we can add a an optional configuration option to support that. But let's get pstore working first before adding new features. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Anton Vorontsov <cbouatmailru@gmail.com> Cc: Colin Cross <ccross@android.com> Cc: Olof Johansson <olof@lixom.net> Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Rob Herring <rob.herring@calxeda.com> [tony@atomide.com: updated description] Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* | Merge branch 'for-linus' of ↵Linus Torvalds2014-12-1231-641/+2739
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs update from Chris Mason: "From a feature point of view, most of the code here comes from Miao Xie and others at Fujitsu to implement scrubbing and replacing devices on raid56. This has been in development for a while, and it's a big improvement. Filipe and Josef have a great assortment of fixes, many of which solve problems corruptions either after a crash or in error conditions. I still have a round two from Filipe for next week that solves corruptions with discard and block group removal" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (62 commits) Btrfs: make get_caching_control unconditionally return the ctl Btrfs: fix unprotected deletion from pending_chunks list Btrfs: fix fs mapping extent map leak Btrfs: fix memory leak after block remove + trimming Btrfs: make btrfs_abort_transaction consider existence of new block groups Btrfs: fix race between writing free space cache and trimming Btrfs: fix race between fs trimming and block group remove/allocation Btrfs, replace: enable dev-replace for raid56 Btrfs: fix freeing used extents after removing empty block group Btrfs: fix crash caused by block group removal Btrfs: fix invalid block group rbtree access after bg is removed Btrfs, raid56: fix use-after-free problem in the final device replace procedure on raid56 Btrfs, replace: write raid56 parity into the replace target device Btrfs, replace: write dirty pages into the replace target device Btrfs, raid56: support parity scrub on raid56 Btrfs, raid56: use a variant to record the operation type Btrfs, scrub: repair the common data on RAID5/6 if it is corrupted Btrfs, raid56: don't change bbio and raid_map Btrfs: remove unnecessary code of stripe_index assignment in __btrfs_map_block Btrfs: remove noused bbio_ret in __btrfs_map_block in condition ...
| * \ Merge branch 'raid56-scrub-replace' of git://github.com/miaoxie/linux-btrfs ↵Chris Mason2014-12-0319-229/+1684
| |\ \ | | | | | | | | | | | | into for-linus
| | * | Btrfs, replace: enable dev-replace for raid56Zhao Lei2014-12-031-5/+0
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
| | * | Btrfs, raid56: fix use-after-free problem in the final device replace ↵Miao Xie2014-12-036-20/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | procedure on raid56 The commit c404e0dc (Btrfs: fix use-after-free in the finishing procedure of the device replace) fixed a use-after-free problem which happened when removing the source device at the end of device replace, but at that time, btrfs didn't support device replace on raid56, so we didn't fix the problem on the raid56 profile. Currently, we implemented device replace for raid56, so we need kick that problem out before we enable that function for raid56. The fix method is very simple, we just increase the bio per-cpu counter before we submit a raid56 io, and decrease the counter when the raid56 io ends. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
| | * | Btrfs, replace: write raid56 parity into the replace target deviceMiao Xie2014-12-032-1/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This function reused the code of parity scrub, and we just write the right parity or corrected parity into the target device before the parity scrub end. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
| | * | Btrfs, replace: write dirty pages into the replace target deviceMiao Xie2014-12-033-43/+97
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The implementation is simple: - In order to avoid changing the code logic of btrfs_map_bio and RAID56, we add the stripes of the replace target devices at the end of the stripe array in btrfs bio, and we sort those target device stripes in the array. And we keep the number of the target device stripes in the btrfs bio. - Except write operation on RAID56, all the other operation don't take the target device stripes into account. - When we do write operation, we read the data from the common devices and calculate the parity. Then write the dirty data and new parity out, at this time, we will find the relative replace target stripes and wirte the relative data into it. Note: The function that copying old data on the source device to the target device was implemented in the past, it is similar to the other RAID type. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
| | * | Btrfs, raid56: support parity scrub on raid56Miao Xie2014-12-033-20/+1115
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The implementation is: - Read and check all the data with checksum in the same stripe. All the data which has checksum is COW data, and we are sure that it is not changed though we don't lock the stripe. because the space of that data just can be reclaimed after the current transction is committed, and then the fs can use it to store the other data, but when doing scrub, we hold the current transaction, that is that data can not be recovered, it is safe that read and check it out of the stripe lock. - Lock the stripe - Read out all the data without checksum and parity The data without checksum and the parity may be changed if we don't lock the stripe, so we need read it in the stripe lock context. - Check the parity - Re-calculate the new parity and write back it if the old parity is not right - Unlock the stripe If we can not read out the data or the data we read is corrupted, we will try to repair it. If the repair fails. we will mark the horizontal sub-stripe(pages on the same horizontal) as corrupted sub-stripe, and we will skip the parity check and repair of that horizontal sub-stripe. And in order to skip the horizontal sub-stripe that has no data, we introduce a bitmap. If there is some data on the horizontal sub-stripe, we will the relative bit to 1, and when we check and repair the parity, we will skip those horizontal sub-stripes that the relative bits is 0. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
| | * | Btrfs, raid56: use a variant to record the operation typeMiao Xie2014-12-031-14/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We will introduce new operation type later, if we still use integer variant as bool variant to record the operation type, we would add new variant and increase the size of raid bio structure. It is not good, by this patch, we define different number for different operation, and we can just use a variant to record the operation type. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
| | * | Btrfs, scrub: repair the common data on RAID5/6 if it is corruptedMiao Xie2014-12-035-33/+235
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implement the RAID5/6 common data repair function, the implementation is similar to the scrub on the other RAID such as RAID1, the differentia is that we don't read the data from the mirror, we use the data repair function of RAID5/6. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
| | * | Btrfs, raid56: don't change bbio and raid_mapMiao Xie2014-12-031-19/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because we will reuse bbio and raid_map during the scrub later, it is better that we don't change any variant of bbio and don't free it at the end of IO request. So we introduced similar variants into the raid bio, and don't access those bbio's variants any more. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
| | * | Btrfs: remove unnecessary code of stripe_index assignment in __btrfs_map_blockZhao Lei2014-12-031-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | stripe_index's value was set again in latter line: stripe_index = 0; Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.cz>
| | * | Btrfs: remove noused bbio_ret in __btrfs_map_block in conditionZhao Lei2014-12-031-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bbio_ret in this condition is always !NULL because previous code already have a check-and-skip: 4908 if (!bbio_ret) 4909 goto out; Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.cz>
| * | | Btrfs: make get_caching_control unconditionally return the ctlJosef Bacik2014-12-031-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This was written when we didn't do a caching control for the fast free space cache loading. However we started doing that a long time ago, and there is still a small window of time that we could be caching the block group the fast way, so if there is a caching_ctl at all on the block group just return it, the callers all wait properly for what they want. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | Btrfs: fix unprotected deletion from pending_chunks listFilipe Manana2014-12-031-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On block group remove if the corresponding extent map was on the transaction->pending_chunks list, we were deleting the extent map from that list, through remove_extent_mapping(), without any synchronization with chunk allocation (which iterates that list and adds new elements to it). Fix this by ensure that this is done while the chunk mutex is held, since that's the mutex that protects the list in the chunk allocation code path. This applies on top (depends on) of my previous patch titled: "Btrfs: fix race between fs trimming and block group remove/allocation" But the issue in fact was already present before that change, it only became easier to hit after Josef's 3.18 patch that added automatic removal of empty block groups. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | Btrfs: fix fs mapping extent map leakFilipe Manana2014-12-032-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On chunk allocation error (label "error_del_extent"), after adding the extent map to the tree and to the pending chunks list, we would leave decrementing the extent map's refcount by 2 instead of 3 (our allocation + tree reference + list reference). Also, on chunk/block group removal, if the block group was on the list pending_chunks we weren't decrementing the respective list reference. Detected by 'rmmod btrfs': [20770.105881] kmem_cache_destroy btrfs_extent_map: Slab cache still has objects [20770.106127] CPU: 2 PID: 11093 Comm: rmmod Tainted: G W L 3.17.0-rc5-btrfs-next-1+ #1 [20770.106128] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [20770.106130] 0000000000000000 ffff8800ba867eb8 ffffffff813e7a13 ffff8800a2e11040 [20770.106132] ffff8800ba867ed0 ffffffff81105d0c 0000000000000000 ffff8800ba867ee0 [20770.106134] ffffffffa035d65e ffff8800ba867ef0 ffffffffa03b0654 ffff8800ba867f78 [20770.106136] Call Trace: [20770.106142] [<ffffffff813e7a13>] dump_stack+0x45/0x56 [20770.106145] [<ffffffff81105d0c>] kmem_cache_destroy+0x4b/0x90 [20770.106164] [<ffffffffa035d65e>] extent_map_exit+0x1a/0x1c [btrfs] [20770.106176] [<ffffffffa03b0654>] exit_btrfs_fs+0x27/0x9d3 [btrfs] [20770.106179] [<ffffffff8109dc97>] SyS_delete_module+0x153/0x1c4 [20770.106182] [<ffffffff8121261b>] ? trace_hardirqs_on_thunk+0x3a/0x3c [20770.106184] [<ffffffff813ebf52>] system_call_fastpath+0x16/0x1b This applies on top (depends on) of my previous patch titled: "Btrfs: fix race between fs trimming and block group remove/allocation" But the issue in fact was already present before that change, it only became easier to hit after Josef's 3.18 patch that added automatic removal of empty block groups. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | Btrfs: fix memory leak after block remove + trimmingFilipe Manana2014-12-031-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There was a free space entry structure memeory leak if a block group is remove while a free space entry is being trimmed, which the following diagram explains: CPU 1 CPU 2 btrfs_trim_block_group() trim_no_bitmap() remove free space entry from block group cache's rbtree do_trimming() btrfs_remove_block_group() btrfs_remove_free_space_cache() add back free space entry to block group's cache rbtree btrfs_put_block_group() (...) btrfs_put_block_group() kfree(bg->free_space_ctl) kfree(bg) The free space entry added after doing the discard of its respective range ends up never being freed. Detected after doing an "rmmod btrfs" after running the stress test recently submitted for fstests: [ 8234.642212] kmem_cache_destroy btrfs_free_space: Slab cache still has objects [ 8234.642657] CPU: 1 PID: 32276 Comm: rmmod Tainted: G W L 3.17.0-rc5-btrfs-next-2+ #1 [ 8234.642660] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [ 8234.642664] 0000000000000000 ffff8801af1b3eb8 ffffffff8140c7b6 ffff8801dbedd0c0 [ 8234.642670] ffff8801af1b3ed0 ffffffff811149ce 0000000000000000 ffff8801af1b3ee0 [ 8234.642676] ffffffffa042dbe7 ffff8801af1b3ef0 ffffffffa0487422 ffff8801af1b3f78 [ 8234.642682] Call Trace: [ 8234.642692] [<ffffffff8140c7b6>] dump_stack+0x4d/0x66 [ 8234.642699] [<ffffffff811149ce>] kmem_cache_destroy+0x4d/0x92 [ 8234.642731] [<ffffffffa042dbe7>] btrfs_destroy_cachep+0x63/0x76 [btrfs] [ 8234.642757] [<ffffffffa0487422>] exit_btrfs_fs+0x9/0xbe7 [btrfs] [ 8234.642762] [<ffffffff810a76a5>] SyS_delete_module+0x155/0x1c6 [ 8234.642768] [<ffffffff8122a7eb>] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 8234.642773] [<ffffffff814122d2>] system_call_fastpath+0x16/0x1b This applies on top (depends on) of my previous patch titled: "Btrfs: fix race between fs trimming and block group remove/allocation" Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | Btrfs: make btrfs_abort_transaction consider existence of new block groupsFilipe Manana2014-12-032-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the transaction handle doesn't have used blocks but has created new block groups make sure we turn the fs into readonly mode too. This is because the new block groups didn't get all their metadata persisted into the chunk and device trees, and therefore if a subsequent transaction starts, allocates space from the new block groups, writes data or metadata into that space, commits successfully and then after we unmount and mount the filesystem again, the same space can be allocated again for a new block group, resulting in file data or metadata corruption. Example where we don't abort the transaction when we fail to finish the chunk allocation (add items to the chunk and device trees) and later a future transaction where the block group is removed fails because it can't find the chunk item in the chunk tree: [25230.404300] WARNING: CPU: 0 PID: 7721 at fs/btrfs/super.c:260 __btrfs_abort_transaction+0x50/0xfc [btrfs]() [25230.404301] BTRFS: Transaction aborted (error -28) [25230.404302] Modules linked in: btrfs dm_flakey nls_utf8 fuse xor raid6_pq ntfs vfat msdos fat xfs crc32c_generic libcrc32c ext3 jbd ext2 dm_mod nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc loop psmouse i2c_piix4 i2ccore parport_pc parport processor button pcspkr serio_raw thermal_sys evdev microcode ext4 crc16 jbd2 mbcache sr_mod cdrom ata_generic sg sd_mod crc_t10dif crct10dif_generic crct10dif_common virtio_scsi floppy e1000 ata_piix libata virtio_pci virtio_ring scsi_mod virtio [last unloaded: btrfs] [25230.404325] CPU: 0 PID: 7721 Comm: xfs_io Not tainted 3.17.0-rc5-btrfs-next-1+ #1 [25230.404326] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [25230.404328] 0000000000000000 ffff88004581bb08 ffffffff813e7a13 ffff88004581bb50 [25230.404330] ffff88004581bb40 ffffffff810423aa ffffffffa049386a 00000000ffffffe4 [25230.404332] ffffffffa05214c0 000000000000240c ffff88010fc8f800 ffff88004581bba8 [25230.404334] Call Trace: [25230.404338] [<ffffffff813e7a13>] dump_stack+0x45/0x56 [25230.404342] [<ffffffff810423aa>] warn_slowpath_common+0x7f/0x98 [25230.404351] [<ffffffffa049386a>] ? __btrfs_abort_transaction+0x50/0xfc [btrfs] [25230.404353] [<ffffffff8104240b>] warn_slowpath_fmt+0x48/0x50 [25230.404362] [<ffffffffa049386a>] __btrfs_abort_transaction+0x50/0xfc [btrfs] [25230.404374] [<ffffffffa04a8c43>] btrfs_create_pending_block_groups+0x10c/0x135 [btrfs] [25230.404387] [<ffffffffa04b77fd>] __btrfs_end_transaction+0x7e/0x2de [btrfs] [25230.404398] [<ffffffffa04b7a6d>] btrfs_end_transaction+0x10/0x12 [btrfs] [25230.404408] [<ffffffffa04a3d64>] btrfs_check_data_free_space+0x111/0x1f0 [btrfs] [25230.404421] [<ffffffffa04c53bd>] __btrfs_buffered_write+0x160/0x48d [btrfs] [25230.404425] [<ffffffff811a9268>] ? cap_inode_need_killpriv+0x2d/0x37 [25230.404429] [<ffffffff810f6501>] ? get_page+0x1a/0x2b [25230.404441] [<ffffffffa04c7c95>] btrfs_file_write_iter+0x321/0x42f [btrfs] [25230.404443] [<ffffffff8110f5d9>] ? handle_mm_fault+0x7f3/0x846 [25230.404446] [<ffffffff813e98c5>] ? mutex_unlock+0x16/0x18 [25230.404449] [<ffffffff81138d68>] new_sync_write+0x7c/0xa0 [25230.404450] [<ffffffff81139401>] vfs_write+0xb0/0x112 [25230.404452] [<ffffffff81139c9d>] SyS_pwrite64+0x66/0x84 [25230.404454] [<ffffffff813ebf52>] system_call_fastpath+0x16/0x1b [25230.404455] ---[ end trace 5aa5684fdf47ab38 ]--- [25230.404458] BTRFS warning (device sdc): btrfs_create_pending_block_groups:9228: Aborting unused transaction(No space left). [25288.084814] BTRFS: error (device sdc) in btrfs_free_chunk:2509: errno=-2 No such entry (Failed lookup while freeing chunk.) Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | Btrfs: fix race between writing free space cache and trimmingFilipe Manana2014-12-033-6/+71
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Trimming is completely transactionless, and the way it operates consists of hiding free space entries from a block group, perform the trim/discard and then make the free space entries visible again. Therefore while a free space entry is being trimmed, we can have free space cache writing running in parallel (as part of a transaction commit) which will miss the free space entry. This means that an unmount (or crash/reboot) after that transaction commit and mount again before another transaction starts/commits after the discard finishes, we will have some free space that won't be used again unless the free space cache is rebuilt. After the unmount, fsck (btrfsck, btrfs check) reports the issue like the following example: *** fsck.btrfs output *** checking extents checking free space cache There is no free space entry for 521764864-521781248 There is no free space entry for 521764864-1103101952 cache appears valid but isnt 29360128 Checking filesystem on /dev/sdc UUID: b4789e27-4774-4626-98e9-ae8dfbfb0fb5 found 1235681286 bytes used err is -22 (...) Another issue caused by this race is a crash while writing bitmap entries to the cache, because while the cache writeout task accesses the bitmaps, the trim task can be concurrently modifying the bitmap or worse might be freeing the bitmap. The later case results in the following crash: [55650.804460] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC [55650.804835] Modules linked in: btrfs dm_flakey dm_mod crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc loop parport_pc parport i2c_piix4 psmouse evdev pcspkr microcode processor i2ccore serio_raw thermal_sys button ext4 crc16 jbd2 mbcache sg sd_mod crc_t10dif sr_mod cdrom crct10dif_generic crct10dif_common ata_generic virtio_scsi floppy ata_piix libata virtio_pci virtio_ring virtio scsi_mod e1000 [last unloaded: btrfs] [55650.806169] CPU: 1 PID: 31002 Comm: btrfs-transacti Tainted: G W 3.17.0-rc5-btrfs-next-1+ #1 [55650.806493] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [55650.806867] task: ffff8800b12f6410 ti: ffff880071538000 task.ti: ffff880071538000 [55650.807166] RIP: 0010:[<ffffffffa037cf45>] [<ffffffffa037cf45>] write_bitmap_entries+0x65/0xbb [btrfs] [55650.807514] RSP: 0018:ffff88007153bc30 EFLAGS: 00010246 [55650.807687] RAX: 000000005d1ec000 RBX: ffff8800a665df08 RCX: 0000000000000400 [55650.807885] RDX: ffff88005d1ec000 RSI: 6b6b6b6b6b6b6b6b RDI: ffff88005d1ec000 [55650.808017] RBP: ffff88007153bc58 R08: 00000000ddd51536 R09: 00000000000001e0 [55650.808017] R10: 0000000000000000 R11: 0000000000000037 R12: 6b6b6b6b6b6b6b6b [55650.808017] R13: ffff88007153bca8 R14: 6b6b6b6b6b6b6b6b R15: ffff88007153bc98 [55650.808017] FS: 0000000000000000(0000) GS:ffff88023ec80000(0000) knlGS:0000000000000000 [55650.808017] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [55650.808017] CR2: 0000000002273b88 CR3: 00000000b18f6000 CR4: 00000000000006e0 [55650.808017] Stack: [55650.808017] ffff88020e834e00 ffff880172d68db0 0000000000000000 ffff88019257c800 [55650.808017] ffff8801d42ea720 ffff88007153bd10 ffffffffa037d2fa ffff880224e99180 [55650.808017] ffff8801469a6188 ffff880224e99140 ffff880172d68c50 00000003000000b7 [55650.808017] Call Trace: [55650.808017] [<ffffffffa037d2fa>] __btrfs_write_out_cache+0x1ea/0x37f [btrfs] [55650.808017] [<ffffffffa037d959>] btrfs_write_out_cache+0xa1/0xd8 [btrfs] [55650.808017] [<ffffffffa033936b>] btrfs_write_dirty_block_groups+0x4b5/0x505 [btrfs] [55650.808017] [<ffffffffa03aa98e>] commit_cowonly_roots+0x15e/0x1f7 [btrfs] [55650.808017] [<ffffffff813eb9c7>] ? _raw_spin_lock+0xe/0x10 [55650.808017] [<ffffffffa0346e46>] btrfs_commit_transaction+0x411/0x882 [btrfs] [55650.808017] [<ffffffffa03432a4>] transaction_kthread+0xf2/0x1a4 [btrfs] [55650.808017] [<ffffffffa03431b2>] ? btrfs_cleanup_transaction+0x3d8/0x3d8 [btrfs] [55650.808017] [<ffffffff8105966b>] kthread+0xb7/0xbf [55650.808017] [<ffffffff810595b4>] ? __kthread_parkme+0x67/0x67 [55650.808017] [<ffffffff813ebeac>] ret_from_fork+0x7c/0xb0 [55650.808017] [<ffffffff810595b4>] ? __kthread_parkme+0x67/0x67 [55650.808017] Code: 4c 89 ef 8d 70 ff e8 d4 fc ff ff 41 8b 45 34 41 39 45 30 7d 5c 31 f6 4c 89 ef e8 80 f6 ff ff 49 8b 7d 00 4c 89 f6 b9 00 04 00 00 <f3> a5 4c 89 ef 41 8b 45 30 8d 70 ff e8 a3 fc ff ff 41 8b 45 34 [55650.808017] RIP [<ffffffffa037cf45>] write_bitmap_entries+0x65/0xbb [btrfs] [55650.808017] RSP <ffff88007153bc30> [55650.815725] ---[ end trace 1c032e96b149ff86 ]--- Fix this by serializing both tasks in such a way that cache writeout doesn't wait for the trim/discard of free space entries to finish and doesn't miss any free space entry. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | Btrfs: fix race between fs trimming and block group remove/allocationFilipe Manana2014-12-036-21/+140
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Our fs trim operation, which is completely transactionless (doesn't start or joins an existing transaction) consists of visiting all block groups and then for each one to iterate its free space entries and perform a discard operation against the space range represented by the free space entries. However before performing a discard, the corresponding free space entry is removed from the free space rbtree, and when the discard completes it is added back to the free space rbtree. If a block group remove operation happens while the discard is ongoing (or before it starts and after a free space entry is hidden), we end up not waiting for the discard to complete, remove the extent map that maps logical address to physical addresses and the corresponding chunk metadata from the the chunk and device trees. After that and before the discard completes, the current running transaction can finish and a new one start, allowing for new block groups that map to the same physical addresses to be allocated and written to. So fix this by keeping the extent map in memory until the discard completes so that the same physical addresses aren't reused before it completes. If the physical locations that are under a discard operation end up being used for a new metadata block group for example, and dirty metadata extents are written before the discard finishes (the VM might call writepages() of our btree inode's i_mapping for example, or an fsync log commit happens) we end up overwriting metadata with zeroes, which leads to errors from fsck like the following: checking extents Check tree block failed, want=833912832, have=0 Check tree block failed, want=833912832, have=0 Check tree block failed, want=833912832, have=0 Check tree block failed, want=833912832, have=0 Check tree block failed, want=833912832, have=0 read block failed check_tree_block owner ref check failed [833912832 16384] Errors found in extent allocation tree or chunk allocation checking free space cache checking fs roots Check tree block failed, want=833912832, have=0 Check tree block failed, want=833912832, have=0 Check tree block failed, want=833912832, have=0 Check tree block failed, want=833912832, have=0 Check tree block failed, want=833912832, have=0 read block failed check_tree_block root 5 root dir 256 error root 5 inode 260 errors 2001, no inode item, link count wrong unresolved ref dir 256 index 0 namelen 8 name foobar_3 filetype 1 errors 6, no dir index, no inode ref root 5 inode 262 errors 2001, no inode item, link count wrong unresolved ref dir 256 index 0 namelen 8 name foobar_5 filetype 1 errors 6, no dir index, no inode ref root 5 inode 263 errors 2001, no inode item, link count wrong (...) Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | Btrfs: fix freeing used extents after removing empty block groupFilipe Manana2014-12-031-11/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a race between adding a block group to the list of the unused block groups and removing an unused block group (cleaner kthread) that leads to freeing extents that are in use or a crash during transaction commmit. Basically the cleaner kthread, when executing btrfs_delete_unused_bgs(), might catch the newly added block group to the list fs_info->unused_bgs and clear the range representing the whole group from fs_info->freed_extents[] before the task that added the block group to the list (running update_block_group()) marked the last freed extent as dirty in fs_info->freed_extents (pinned_extents). That is: CPU 1 CPU 2 btrfs_delete_unused_bgs() update_block_group() add block group to fs_info->unused_bgs got block group from the list clear_extent_bits for the whole block group range in freed_extents[] set_extent_dirty for the range covering the freed extent in freed_extents[] (fs_info->pinned_extents) block group deleted, and a new block group with the same logical address is created reserve space from the new block group for new data or metadata - the reserved space overlaps the range specified by CPU 1 for set_extent_dirty() commit transaction find all ranges marked as dirty in fs_info->pinned_extents, clear them and add them to the free space cache Alternatively, if CPU 2 doesn't create a new block group with the same logical address, we get a crash/BUG_ON at transaction commit when unpining extent ranges because we can't find a block group for the range marked as dirty by CPU 1. Sample trace: [ 2163.426462] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC [ 2163.426640] Modules linked in: btrfs xor raid6_pq dm_thin_pool dm_persistent_data dm_bio_prison dm_bufio crc32c_generic libcrc32c dm_mod nfsd auth_rpc gss oid_registry nfs_acl nfs lockd fscache sunrpc loop psmouse parport_pc parport i2c_piix4 processor thermal_sys i2ccore evdev button pcspkr microcode serio_raw ext4 crc16 jbd2 mbcache sg sr_mod cdrom sd_mod crc_t10dif crct10dif_generic crct10dif_common ata_generic virtio_scsi floppy ata_piix libata e1000 scsi_mod virtio_pci virtio_ring virtio [ 2163.428209] CPU: 0 PID: 11858 Comm: btrfs-transacti Tainted: G W 3.17.0-rc5-btrfs-next-1+ #1 [ 2163.428519] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [ 2163.428875] task: ffff88009f2c0650 ti: ffff8801356bc000 task.ti: ffff8801356bc000 [ 2163.429157] RIP: 0010:[<ffffffffa037728e>] [<ffffffffa037728e>] unpin_extent_range.isra.58+0x62/0x192 [btrfs] [ 2163.429562] RSP: 0018:ffff8801356bfda8 EFLAGS: 00010246 [ 2163.429802] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 2163.429990] RDX: 0000000041bfffff RSI: 0000000001c00000 RDI: ffff880024307080 [ 2163.430042] RBP: ffff8801356bfde8 R08: 0000000000000068 R09: ffff88003734f118 [ 2163.430042] R10: ffff8801356bfcb8 R11: fffffffffffffb69 R12: ffff8800243070d0 [ 2163.430042] R13: 0000000083c04000 R14: ffff8800751b0f00 R15: ffff880024307000 [ 2163.430042] FS: 0000000000000000(0000) GS:ffff88013f400000(0000) knlGS:0000000000000000 [ 2163.430042] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 2163.430042] CR2: 00007ff10eb43fc0 CR3: 0000000004cb8000 CR4: 00000000000006f0 [ 2163.430042] Stack: [ 2163.430042] ffff8800243070d0 0000000083c08000 0000000083c07fff ffff88012d6bc800 [ 2163.430042] ffff8800243070d0 ffff8800751b0f18 ffff8800751b0f00 0000000000000000 [ 2163.430042] ffff8801356bfe18 ffffffffa037a481 0000000083c04000 0000000083c07fff [ 2163.430042] Call Trace: [ 2163.430042] [<ffffffffa037a481>] btrfs_finish_extent_commit+0xac/0xbf [btrfs] [ 2163.430042] [<ffffffffa038c06d>] btrfs_commit_transaction+0x6ee/0x882 [btrfs] [ 2163.430042] [<ffffffffa03881f1>] transaction_kthread+0xf2/0x1a4 [btrfs] [ 2163.430042] [<ffffffffa03880ff>] ? btrfs_cleanup_transaction+0x3d8/0x3d8 [btrfs] [ 2163.430042] [<ffffffff8105966b>] kthread+0xb7/0xbf [ 2163.430042] [<ffffffff810595b4>] ? __kthread_parkme+0x67/0x67 [ 2163.430042] [<ffffffff813ebeac>] ret_from_fork+0x7c/0xb0 [ 2163.430042] [<ffffffff810595b4>] ? __kthread_parkme+0x67/0x67 So fix this by making update_block_group() first set the range as dirty in pinned_extents before adding the block group to the unused_bgs list. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | Btrfs: fix crash caused by block group removalFilipe Manana2014-12-032-0/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we remove a block group (because it became empty), we might have left a caching_ctl structure in fs_info->caching_block_groups that points to the block group and is accessed at transaction commit time. This results in accessing an invalid or incorrect block group. This issue became visible after Josef's patch "Btrfs: remove empty block groups automatically". So if the block group is removed make sure we don't leave a dangling caching_ctl in caching_block_groups. Sample crash trace: [58380.439449] BUG: unable to handle kernel paging request at ffff8801446eaeb8 [58380.439707] IP: [<ffffffffa03f6d05>] block_group_cache_done.isra.21+0xc/0x1c [btrfs] [58380.440879] PGD 1acb067 PUD 23f5ff067 PMD 23f5db067 PTE 80000001446ea060 [58380.441220] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC [58380.441486] Modules linked in: btrfs crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc loop psmouse processor i2c_piix4 parport_pc parport pcspkr serio_raw evdev i2ccore thermal_sys microcode button ext4 crc16 jbd2 mbcache sr_mod cdrom ata_generic sg sd_mod crc_t10dif crct10dif_generic crct10dif_common virtio_scsi floppy ata_piix e1000 libata virtio_pci scsi_mod virtio_ring virtio [last unloaded: btrfs] [58380.443238] CPU: 3 PID: 25728 Comm: btrfs-transacti Tainted: G W 3.17.0-rc5-btrfs-next-1+ #1 [58380.443238] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [58380.443238] task: ffff88013ac82090 ti: ffff88013896c000 task.ti: ffff88013896c000 [58380.443238] RIP: 0010:[<ffffffffa03f6d05>] [<ffffffffa03f6d05>] block_group_cache_done.isra.21+0xc/0x1c [btrfs] [58380.443238] RSP: 0018:ffff88013896fdd8 EFLAGS: 00010283 [58380.443238] RAX: ffff880222cae850 RBX: ffff880119ba74c0 RCX: 0000000000000000 [58380.443238] RDX: 0000000000000000 RSI: ffff880185e16800 RDI: ffff8801446eaeb8 [58380.443238] RBP: ffff88013896fdd8 R08: ffff8801a9ca9fa8 R09: ffff88013896fc60 [58380.443238] R10: ffff88013896fd28 R11: 0000000000000000 R12: ffff880222cae000 [58380.443238] R13: ffff880222cae850 R14: ffff880222cae6b0 R15: ffff8801446eae00 [58380.443238] FS: 0000000000000000(0000) GS:ffff88023ed80000(0000) knlGS:0000000000000000 [58380.443238] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [58380.443238] CR2: ffff8801446eaeb8 CR3: 0000000001811000 CR4: 00000000000006e0 [58380.443238] Stack: [58380.443238] ffff88013896fe18 ffffffffa03fe2d5 ffff880222cae850 ffff880185e16800 [58380.443238] ffff88000dc41c20 0000000000000000 ffff8801a9ca9f00 0000000000000000 [58380.443238] ffff88013896fe80 ffffffffa040fbcf ffff88018b0dcdb0 ffff88013ac82090 [58380.443238] Call Trace: [58380.443238] [<ffffffffa03fe2d5>] btrfs_prepare_extent_commit+0x5a/0xd7 [btrfs] [58380.443238] [<ffffffffa040fbcf>] btrfs_commit_transaction+0x45c/0x882 [btrfs] [58380.443238] [<ffffffffa040c058>] transaction_kthread+0xf2/0x1a4 [btrfs] [58380.443238] [<ffffffffa040bf66>] ? btrfs_cleanup_transaction+0x3d8/0x3d8 [btrfs] [58380.443238] [<ffffffff8105966b>] kthread+0xb7/0xbf [58380.443238] [<ffffffff810595b4>] ? __kthread_parkme+0x67/0x67 [58380.443238] [<ffffffff813ebeac>] ret_from_fork+0x7c/0xb0 [58380.443238] [<ffffffff810595b4>] ? __kthread_parkme+0x67/0x67 Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | Btrfs: fix invalid block group rbtree access after bg is removedFilipe Manana2014-12-031-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we grab a block group, for example in btrfs_trim_fs(), we will be holding a reference on it but the block group can be removed after we got it (via btrfs_remove_block_group), which means it will no longer be part of the rbtree. However, btrfs_remove_block_group() was only calling rb_erase() which leaves the block group's rb_node left and right child pointers with the same content they had before calling rb_erase. This was dangerous because a call to next_block_group() would access the node's left and right child pointers (via rb_next), which can be no longer valid. Fix this by clearing a block group's node after removing it from the tree, and have next_block_group() do a tree search to get the next block group instead of using rb_next() if our block group was removed. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | Btrfs: fix snapshot inconsistency after a file write followed by truncateFilipe Manana2014-11-255-24/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If right after starting the snapshot creation ioctl we perform a write against a file followed by a truncate, with both operations increasing the file's size, we can get a snapshot tree that reflects a state of the source subvolume's tree where the file truncation happened but the write operation didn't. This leaves a gap between 2 file extent items of the inode, which makes btrfs' fsck complain about it. For example, if we perform the following file operations: $ mkfs.btrfs -f /dev/vdd $ mount /dev/vdd /mnt $ xfs_io -f \ -c "pwrite -S 0xaa -b 32K 0 32K" \ -c "fsync" \ -c "pwrite -S 0xbb -b 32770 16K 32770" \ -c "truncate 90123" \ /mnt/foobar and the snapshot creation ioctl was just called before the second write, we often can get the following inode items in the snapshot's btree: item 120 key (257 INODE_ITEM 0) itemoff 7987 itemsize 160 inode generation 146 transid 7 size 90123 block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0 flags 0x0 item 121 key (257 INODE_REF 256) itemoff 7967 itemsize 20 inode ref index 282 namelen 10 name: foobar item 122 key (257 EXTENT_DATA 0) itemoff 7914 itemsize 53 extent data disk byte 1104855040 nr 32768 extent data offset 0 nr 32768 ram 32768 extent compression 0 item 123 key (257 EXTENT_DATA 53248) itemoff 7861 itemsize 53 extent data disk byte 0 nr 0 extent data offset 0 nr 40960 ram 40960 extent compression 0 There's a file range, corresponding to the interval [32K; ALIGN(16K + 32770, 4096)[ for which there's no file extent item covering it. This is because the file write and file truncate operations happened both right after the snapshot creation ioctl called btrfs_start_delalloc_inodes(), which means we didn't start and wait for the ordered extent that matches the write and, in btrfs_setsize(), we were able to call btrfs_cont_expand() before being able to commit the current transaction in the snapshot creation ioctl. So this made it possibe to insert the hole file extent item in the source subvolume (which represents the region added by the truncate) right before the transaction commit from the snapshot creation ioctl. Btrfs' fsck tool complains about such cases with a message like the following: "root 331 inode 257 errors 100, file extent discount" >From a user perspective, the expectation when a snapshot is created while those file operations are being performed is that the snapshot will have a file that either: 1) is empty 2) only the first write was captured 3) only the 2 writes were captured 4) both writes and the truncation were captured But never capture a state where only the first write and the truncation were captured (since the second write was performed before the truncation). A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | Btrfs: ensure send always works on roots without orphansFilipe Manana2014-11-252-29/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the logic from the snapshot creation ioctl into send. This avoids doing the transaction commit if send isn't used, and ensures that if a crash/reboot happens after the transaction commit that created the snapshot and before the transaction commit that switched the commit root, send will not get a commit root that differs from the main root (that has orphan items). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | Btrfs: fix freeing used extent after removing empty block groupFilipe Manana2014-11-251-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Due to ignoring errors returned by clear_extent_bits (at the moment only -ENOMEM is possible), we can end up freeing an extent that is actually in use (i.e. return the extent to the free space cache). The sequence of steps that lead to this: 1) Cleaner thread starts execution and calls btrfs_delete_unused_bgs(), with the goal of freeing empty block groups; 2) btrfs_delete_unused_bgs() finds an empty block group, joins the current transaction (or starts a new one if none is running) and attempts to clear the EXTENT_DIRTY bit for the block group's range from freed_extents[0] and freed_extents[1] (of which one corresponds to fs_info->pinned_extents); 3) Clearing the EXTENT_DIRTY bit (via clear_extent_bits()) fails with -ENOMEM, but such error is ignored and btrfs_delete_unused_bgs() proceeds to delete the block group and the respective chunk, while pinned_extents remains with that bit set for the whole (or a part of the) range covered by the block group; 4) Later while the transaction is still running, the chunk ends up being reused for a new block group (maybe for different purpose, data or metadata), and extents belonging to the new block group are allocated for file data or btree nodes/leafs; 5) The current transaction is committed, meaning that we unpinned one or more extents from the new block group (through btrfs_finish_extent_commit() and unpin_extent_range()) which are now being used for new file data or new metadata (through btrfs_finish_extent_commit() and unpin_extent_range()). And unpinning means we returned the extents to the free space cache of the new block group, which implies those extents can be used for future allocations while they're still in use. Alternatively, we can hit a BUG_ON() when doing a lookup for a block group's cache object in unpin_extent_range() if a new block group didn't end up being allocated for the same chunk (step 4 above). Fix this by not freeing the block group and chunk if we fail to clear the dirty bit. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | Btrfs: include vmalloc.h in check-integrity.cChris Mason2014-11-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fengguang's build monster reported warnings on some arches because we don't have vmalloc.h included Signed-off-by: Chris Mason <clm@fb.com> Reported-by: fengguang.wu@intel.com
| * | | btrfs: Fix a lockdep warning when running xfstest.Qu Wenruo2014-11-253-9/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following lockdep warning is triggered during xfstests: [ 1702.980872] ========================================================= [ 1702.981181] [ INFO: possible irq lock inversion dependency detected ] [ 1702.981482] 3.18.0-rc1 #27 Not tainted [ 1702.981781] --------------------------------------------------------- [ 1702.982095] kswapd0/77 just changed the state of lock: [ 1702.982415] (&delayed_node->mutex){+.+.-.}, at: [<ffffffffa03b0b51>] __btrfs_release_delayed_node+0x41/0x1f0 [btrfs] [ 1702.982794] but this lock took another, RECLAIM_FS-unsafe lock in the past: [ 1702.983160] (&fs_info->dev_replace.lock){+.+.+.} and interrupts could create inverse lock ordering between them. [ 1702.984675] other info that might help us debug this: [ 1702.985524] Chain exists of: &delayed_node->mutex --> &found->groups_sem --> &fs_info->dev_replace.lock [ 1702.986799] Possible interrupt unsafe locking scenario: [ 1702.987681] CPU0 CPU1 [ 1702.988137] ---- ---- [ 1702.988598] lock(&fs_info->dev_replace.lock); [ 1702.989069] local_irq_disable(); [ 1702.989534] lock(&delayed_node->mutex); [ 1702.990038] lock(&found->groups_sem); [ 1702.990494] <Interrupt> [ 1702.990938] lock(&delayed_node->mutex); [ 1702.991407] *** DEADLOCK *** It is because the btrfs_kobj_{add/rm}_device() will call memory allocation with GFP_KERNEL, which may flush fs page cache to free space, waiting for it self to do the commit, causing the deadlock. To solve the problem, move btrfs_kobj_{add/rm}_device() out of the dev_replace lock range, also involing split the btrfs_rm_dev_replace_srcdev() function into remove and free parts. Now only btrfs_rm_dev_replace_remove_srcdev() is called in dev_replace lock range, and kobj_{add/rm} and btrfs_rm_dev_replace_free_srcdev() are called out of the lock range. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | Merge branch 'dev/pending-changes' of ↵Chris Mason2014-11-257-37/+115
| |\ \ \ | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus
| | * | | btrfs: move commit out of sysfs when changing labelDavid Sterba2014-11-121-13/+8
| | | | | | | | | | | | | | | | | | | | Signed-off-by: David Sterba <dsterba@suse.cz>
| | * | | btrfs: move commit out of sysfs when changing featuresDavid Sterba2014-11-121-8/+5
| | | | | | | | | | | | | | | | | | | | Signed-off-by: David Sterba <dsterba@suse.cz>
| | * | | btrfs: introduce pending action: commitDavid Sterba2014-11-122-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In some contexts, like in sysfs handlers, we don't want to trigger a transaction commit. It's a heavy operation, we don't know what external locks may be taken. Instead, make it possible to finish the operation through sync syscall or SYNC_FS ioctl. Signed-off-by: David Sterba <dsterba@suse.cz>
| | * | | btrfs: switch inode_cache option handling to pending changesDavid Sterba2014-11-125-15/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The pending mount option(s) now share namespace and bits with the normal options, and the existing one for (inode_cache) is unset unconditionally at each transaction commit. Introduce a separate namespace for pending changes and enhance the descriptions of the intended change to use separate bits for each action. Signed-off-by: David Sterba <dsterba@suse.cz>
| | * | | btrfs: do commit in sync_fs if there are pending changesDavid Sterba2014-11-121-3/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a pending change is requested, it's not processed unless there is a transaction commit about to happen, not even after sync or SYNC_FS ioctl. For example a remount that toggles the inode_cache option will not take effect after sync on a quiescent filesystem. Signed-off-by: David Sterba <dsterba@suse.cz>
| | * | | btrfs: add support for processing pending changesDavid Sterba2014-11-124-0/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are some actions that modify global filesystem state but cannot be performed at the time of request, but later at the transaction commit time when the filesystem is in a known state. For example enabling new incompat features on-the-fly or issuing transaction commit from unsafe contexts (sysfs handlers). Signed-off-by: David Sterba <dsterba@suse.cz>
| * | | | Btrfs: ensure ordered extent errors aren't missed on fsyncFilipe Manana2014-11-213-0/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When doing a fsync with a fast path we have a time window where we can miss the fact that writeback of some file data failed, and therefore we endup returning success (0) from fsync when we should return an error. The steps that lead to this are the following: 1) We start all ordered extents by calling filemap_fdatawrite_range(); 2) We do some other work like locking the inode's i_mutex, start a transaction, start a log transaction, etc; 3) We enter btrfs_log_inode(), acquire the inode's log_mutex and collect all the ordered extents from inode's ordered tree into a list; 4) But by the time we do ordered extent collection, some ordered extents we started at step 1) might have already completed with an error, and therefore we didn't found them in the ordered tree and had no idea they finished with an error. This makes our fsync return success (0) to userspace, but has no bad effects on the log like for example insertion of file extent items into the log that point to unwritten extents, because the invalid extent maps were removed before the ordered extent completed (in inode.c:btrfs_finish_ordered_io). So after collecting the ordered extents just check if the inode's i_mapping has any error flags set (AS_EIO or AS_ENOSPC) and leave with an error if it does. Whenever writeback fails for a page of an ordered extent, we call mapping_set_error (done in extent_io.c:end_extent_writepage, called by extent_io.c:end_bio_extent_writepage) that sets one of those error flags in the inode's i_mapping flags. This change also has the side effect of fixing the issue where for fast fsyncs we never checked/cleared the error flags from the inode's i_mapping flags, which means that a full fsync performed after a fast fsync could get such errors that belonged to the fast fsync - because the full fsync calls btrfs_wait_ordered_range() which calls filemap_fdatawait_range(), and the later checks for and clears those flags, while for fast fsyncs we never call filemap_fdatawait_range() or anything else that checks for and clears the error flags from the inode's i_mapping. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | | Btrfs: collect only the necessary ordered extents on ranged fsyncFilipe Manana2014-11-213-5/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of collecting all ordered extents from the inode's ordered tree and then wait for all of them to complete, just collect the ones that overlap the fsync range. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | | Btrfs: don't ignore log btree writeback errorsFilipe Manana2014-11-211-6/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If an error happens during writeback of log btree extents, make sure the error is returned to the caller (fsync), so that it takes proper action (commit current transaction) instead of writing a superblock that points to log btrees with all or some nodes that weren't durably persisted. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | | Btrfs: do not move em to modified list when unpinningJosef Bacik2014-11-211-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We use the modified list to keep track of which extents have been modified so we know which ones are candidates for logging at fsync() time. Newly modified extents are added to the list at modification time, around the same time the ordered extent is created. We do this so that we don't have to wait for ordered extents to complete before we know what we need to log. The problem is when something like this happens log extent 0-4k on inode 1 copy csum for 0-4k from ordered extent into log sync log commit transaction log some other extent on inode 1 ordered extent for 0-4k completes and adds itself onto modified list again log changed extents see ordered extent for 0-4k has already been logged at this point we assume the csum has been copied sync log crash On replay we will see the extent 0-4k in the log, drop the original 0-4k extent which is the same one that we are replaying which also drops the csum, and then we won't find the csum in the log for that bytenr. This of course causes us to have errors about not having csums for certain ranges of our inode. So remove the modified list manipulation in unpin_extent_cache, any modified extents should have been added well before now, and we don't want them re-logged. This fixes my test that I could reliably reproduce this problem with. Thanks, cc: stable@vger.kernel.org Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | | Btrfs: make sure logged extents complete in the current transaction V3Josef Bacik2014-11-216-6/+72
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Liu Bo pointed out that my previous fix would lose the generation update in the scenario I described. It is actually much worse than that, we could lose the entire extent if we lose power right after the transaction commits. Consider the following write extent 0-4k log extent in log tree commit transaction < power fail happens here ordered extent completes We would lose the 0-4k extent because it hasn't updated the actual fs tree, and the transaction commit will reset the log so it isn't replayed. If we lose power before the transaction commit we are save, otherwise we are not. Fix this by keeping track of all extents we logged in this transaction. Then when we go to commit the transaction make sure we wait for all of those ordered extents to complete before proceeding. This will make sure that if we lose power after the transaction commit we still have our data. This also fixes the problem of the improperly updated extent generation. Thanks, cc: stable@vger.kernel.org Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | | Btrfs: make sure we wait on logged extents when fsycning two subvolsJosef Bacik2014-11-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we have two fsync()'s race on different subvols one will do all of its work to get into the log_tree, wait on it's outstanding IO, and then allow the log_tree to finish it's commit. The problem is we were just free'ing that subvols logged extents instead of waiting on them, so whoever lost the race wouldn't really have their data on disk. Fix this by waiting properly instead of freeing the logged extents. Thanks, cc: stable@vger.kernel.org Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | | btrfs: fix wrong accounting of raid1 data profile in statfsDavid Sterba2014-11-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The sizes that are obtained from space infos are in raw units and have to be adjusted according to the raid factor. This was missing for f_bavail and df reported doubled size for raid1. Reported-by: Martin Steigerwald <Martin@lichtvoll.de> Fixes: ba7b6e62f420 ("btrfs: adjust statfs calculations according to raid profiles") CC: stable@vger.kernel.org Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
| * | | | btrfs: fix dead lock while running replace and defrag concurrentlyGui Hecheng2014-11-211-30/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This can be reproduced by fstests: btrfs/070 The scenario is like the following: replace worker thread defrag thread --------------------- ------------- copy_nocow_pages_worker btrfs_defrag_file copy_nocow_pages_for_inode ... btrfs_writepages |A| lock_extent_bits extent_write_cache_pages |B| lock_page __extent_writepage ... writepage_delalloc find_lock_delalloc_range |B| lock_extent_bits find_or_create_page pagecache_get_page |A| lock_page This leads to an ABBA pattern deadlock. To fix it, o we just change it to an AABB pattern which means to @unlock_extent_bits() before we @lock_page(), and in this way the @extent_read_full_page_nolock() is no longer in an locked context, so change it back to @extent_read_full_page() to regain protection. o Since we @unlock_extent_bits() earlier, then before @write_page_nocow(), the extent may not really point at the physical block we want, so we have to check it before write. Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com> Tested-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
| * | | | Btrfs: make xattr replace operations atomicFilipe Manana2014-11-214-65/+102
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replacing a xattr consists of doing a lookup for its existing value, delete the current value from the respective leaf, release the search path and then finally insert the new value. This leaves a time window where readers (getxattr, listxattrs) won't see any value for the xattr. Xattrs are used to store ACLs, so this has security implications. This change also fixes 2 other existing issues which were: *) Deleting the old xattr value without verifying first if the new xattr will fit in the existing leaf item (in case multiple xattrs are packed in the same item due to name hash collision); *) Returning -EEXIST when the flag XATTR_CREATE is given and the xattr doesn't exist but we have have an existing item that packs muliple xattrs with the same name hash as the input xattr. In this case we should return ENOSPC. A test case for xfstests follows soon. Thanks to Alexandre Oliva for reporting the non-atomicity of the xattr replace implementation. Reported-by: Alexandre Oliva <oliva@gnu.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | | Btrfs: avoid premature -ENOMEM in clear_extent_bit()Filipe Manana2014-11-211-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We try to allocate an extent state structure before acquiring the extent state tree's spinlock as we might need a new one later and therefore avoid doing later an atomic allocation while holding the tree's spinlock. However we returned -ENOMEM if that initial non-atomic allocation failed, which is a bit excessive since we might end up not needing the pre-allocated extent state at all - for the case where the tree doesn't have any extent states that cover the input range and cover too any other range. Therefore don't return -ENOMEM if that pre-allocation fails. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * | | | Btrfs: don't take the chunk_mutex/dev_list mutex in statfs V2Josef Bacik2014-11-211-25/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Our gluster boxes get several thousand statfs() calls per second, which begins to suck hardcore with all of the lock contention on the chunk mutex and dev list mutex. We don't really need to hold these things, if we have transient weirdness with statfs() because of the chunk allocator we don't care, so remove this locking. We still need the dev_list lock if you mount with -o alloc_start however, which is a good argument for nuking that thing from orbit, but that's a patch for another day. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>