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2015-12-07btrfs: make clear_extent_buffer_uptodate return voidDavid Sterba
Does not return any errors, nor anything from the callgraph. Signed-off-by: David Sterba <dsterba@suse.com>
2015-12-07btrfs: make set_extent_buffer_uptodate return voidDavid Sterba
Does not return any errors, nor anything from the callgraph. Signed-off-by: David Sterba <dsterba@suse.com>
2015-12-07btrfs: remove a trivial helper btrfs_set_buffer_uptodateDavid Sterba
Signed-off-by: David Sterba <dsterba@suse.com>
2015-12-06btrfs: Use xattr handler infrastructureAndreas Gruenbacher
Use the VFS xattr handler infrastructure and get rid of similar code in the filesystem. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-06posix acls: Remove duplicate xattr name definitionsAndreas Gruenbacher
Remove POSIX_ACL_XATTR_{ACCESS,DEFAULT} and GFS2_POSIX_ACL_{ACCESS,DEFAULT} and replace them with the definitions in <include/uapi/linux/xattr.h>. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-03btrfs: use GFP_KERNEL for xattr and acl allocationsDavid Sterba
We don't have to use GFP_NOFS in context of ACL or XATTR actions, not possible to loop through the allocator and it's safe to fail with ENOMEM. Signed-off-by: David Sterba <dsterba@suse.com>
2015-12-03btrfs: use GFP_KERNEL for allocations of workqueuesDavid Sterba
We don't have to use GFP_NOFS to allocate workqueue structures, this is done from mount context or potentially scrub start context, safe to fail in both cases. Signed-off-by: David Sterba <dsterba@suse.com>
2015-12-03btrfs: use GFP_KERNEL for allocations in ioctl handlersDavid Sterba
We don't have to use GFP_NOFS in the ioctl handlers because there's no risk of looping through the allocators back to the filesystem. This patch covers only allocations that are directly in the ioctl handlers. Signed-off-by: David Sterba <dsterba@suse.com>
2015-12-03btrfs: remove wait from struct btrfs_delalloc_workDavid Sterba
The value is 0 and never changes, we can propagate the value, remove wait and the implied dead code. Signed-off-by: David Sterba <dsterba@suse.com>
2015-12-03btrfs: sink parameter wait to btrfs_alloc_delalloc_workDavid Sterba
There's only one caller and single value, we can propagate it down to the callee and remove the unused parameter. Signed-off-by: David Sterba <dsterba@suse.com>
2015-12-03btrfs: make btrfs_close_one_device staticDavid Sterba
Signed-off-by: David Sterba <dsterba@suse.com>
2015-12-03btrfs: make lock_extent static inlineDavid Sterba
One call less reduces stack usage, code slightly reduced as well. Signed-off-by: David Sterba <dsterba@suse.com>
2015-12-03btrfs: drop unused parameter from lock_extent_bitsDavid Sterba
We've always passed 0. Stack usage will slightly decrease. Signed-off-by: David Sterba <dsterba@suse.com>
2015-12-03btrfs: make clear_extent_bit helpers static inlineDavid Sterba
The funcions just wrap the clear_extent_bit API and generate function calls. This increases stack consumption and may negatively affect performance due to icache misses. We can simply make the helpers static inline and keep the type checking and API untouched. The code slightly decreases: text data bss dec hex filename 938667 43670 23144 1005481 f57a9 fs/btrfs/btrfs.ko.before 939651 43670 23144 1006465 f5b81 fs/btrfs/btrfs.ko.after Signed-off-by: David Sterba <dsterba@suse.com>
2015-12-03btrfs: make set_extent_bit helpers static inlineDavid Sterba
The funcions just wrap the set_extent_bit API and generate function calls. This increases stack consumption and may negatively affect performance due to icache misses. We can simply make the helpers static inline and keep the type checking and API untouched. The code slightly increases: text data bss dec hex filename 938427 43670 23144 1005241 f56b9 fs/btrfs/btrfs.ko.before 938667 43670 23144 1005481 f57a9 fs/btrfs/btrfs.ko Signed-off-by: David Sterba <dsterba@suse.com>
2015-12-01btrfs: add .copy_file_range file operationZach Brown
This rearranges the existing COPY_RANGE ioctl implementation so that the .copy_file_range file operation can call the core loop that copies file data extent items. The extent copying loop is lifted up into its own function. It retains the core btrfs error checks that should be shared. Signed-off-by: Zach Brown <zab@redhat.com> [Anna Schumaker: Make flags an unsigned int, Check for COPY_FR_REFLINK] Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-27Merge branch 'for-linus-4.4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "This has Mark Fasheh's patches to fix quota accounting during subvol deletion, which we've been working on for a while now. The patch is pretty small but it's a key fix. Otherwise it's a random assortment" * 'for-linus-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: btrfs: fix balance range usage filters in 4.4-rc btrfs: qgroup: account shared subtree during snapshot delete Btrfs: use btrfs_get_fs_root in resolve_indirect_ref btrfs: qgroup: fix quota disable during rescan Btrfs: fix race between cleaner kthread and space cache writeout Btrfs: fix scrub preventing unused block groups from being deleted Btrfs: fix race between scrub and block group deletion btrfs: fix rcu warning during device replace btrfs: Continue replace when set_block_ro failed btrfs: fix clashing number of the enhanced balance usage filter Btrfs: fix the number of transaction units needed to remove a block group Btrfs: use global reserve when deleting unused block group after ENOSPC Btrfs: tests: checking for NULL instead of IS_ERR() btrfs: fix signed overflows in btrfs_sync_file
2015-11-25btrfs: fix balance range usage filters in 4.4-rcHolger Hoffstätte
There's a regression in 4.4-rc since commit bc3094673f22 (btrfs: extend balance filter usage to take minimum and maximum) in that existing (non-ranged) balance with -dusage=x no longer works; all chunks are skipped. After staring at the code for a while and wondering why a non-ranged balance would even need min and max thresholds (..which then were not set correctly, leading to the bug) I realized that the only problem was the fact that the filter functions were named wrong, thanks to patching copypasta. Simply renaming both functions lets the existing btrfs-progs call balance with -dusage=x and now the non-ranged filter function is invoked, properly using only a single chunk limit. Signed-off-by: Holger Hoffstätte <holger.hoffstaette@googlemail.com> Fixes: bc3094673f22 ("btrfs: extend balance filter usage to take minimum and maximum") Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25btrfs: qgroup: account shared subtree during snapshot deleteMark Fasheh
Commit 0ed4792 ('btrfs: qgroup: Switch to new extent-oriented qgroup mechanism.') removed our qgroup accounting during btrfs_drop_snapshot(). Predictably, this results in qgroup numbers going bad shortly after a snapshot is removed. Fix this by adding a dirty extent record when we encounter extents during our shared subtree walk. This effectively restores the functionality we had with the original shared subtree walking code in 1152651 (btrfs: qgroup: account shared subtrees during snapshot delete). The idea with the original patch (and this one) is that shared subtrees can get skipped during drop_snapshot. The shared subtree walk then allows us a chance to visit those extents and add them to the qgroup work for later processing. This ultimately makes the accounting for drop snapshot work. The new qgroup code nicely handles all the other extents during the tree walk via the ref dec/inc functions so we don't have to add actions beyond what we had originally. Signed-off-by: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25Btrfs: use btrfs_get_fs_root in resolve_indirect_refJosef Bacik
The backref code will look up the fs_root we're trying to resolve our indirect refs for, unfortunately we use btrfs_read_fs_root_no_name, which returns -ENOENT if the ref is 0. This isn't helpful for the qgroup stuff with snapshot delete as it won't be able to search down the snapshot we are deleting, which will cause us to miss roots. So use btrfs_get_fs_root and send false for check_ref so we can always get the root we're looking for. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25btrfs: qgroup: fix quota disable during rescanJustin Maggard
There's a race condition that leads to a NULL pointer dereference if you disable quotas while a quota rescan is running. To fix this, we just need to wait for the quota rescan worker to actually exit before tearing down the quota structures. Signed-off-by: Justin Maggard <jmaggard@netgear.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25Btrfs: fix race between cleaner kthread and space cache writeoutFilipe Manana
When a block group becomes unused and the cleaner kthread is currently running, we can end up getting the current transaction aborted with error -ENOENT when we try to commit the transaction, leading to the following trace: [59779.258768] WARNING: CPU: 3 PID: 5990 at fs/btrfs/extent-tree.c:3740 btrfs_write_dirty_block_groups+0x17c/0x214 [btrfs]() [59779.272594] BTRFS: Transaction aborted (error -2) (...) [59779.291137] Call Trace: [59779.291621] [<ffffffff812566f4>] dump_stack+0x4e/0x79 [59779.292543] [<ffffffff8104d0a6>] warn_slowpath_common+0x9f/0xb8 [59779.293435] [<ffffffffa04cb81f>] ? btrfs_write_dirty_block_groups+0x17c/0x214 [btrfs] [59779.295000] [<ffffffff8104d107>] warn_slowpath_fmt+0x48/0x50 [59779.296138] [<ffffffffa04c2721>] ? write_one_cache_group.isra.32+0x77/0x82 [btrfs] [59779.297663] [<ffffffffa04cb81f>] btrfs_write_dirty_block_groups+0x17c/0x214 [btrfs] [59779.299141] [<ffffffffa0549b0d>] commit_cowonly_roots+0x1de/0x261 [btrfs] [59779.300359] [<ffffffffa04dd5b6>] btrfs_commit_transaction+0x4c4/0x99c [btrfs] [59779.301805] [<ffffffffa04b5df4>] btrfs_sync_fs+0x145/0x1ad [btrfs] [59779.302893] [<ffffffff81196634>] sync_filesystem+0x7f/0x93 (...) [59779.318186] ---[ end trace 577e2daff90da33a ]--- The following diagram illustrates a sequence of steps leading to this problem: CPU 1 CPU 2 <at transaction N> adds bg A to list fs_info->unused_bgs adds bg B to list fs_info->unused_bgs <transaction kthread commits transaction N and wakes up the cleaner kthread> cleaner kthread delete_unused_bgs() sees bg A in list fs_info->unused_bgs btrfs_start_transaction() <transaction N + 1 starts> deletes bg A update_block_group(bg C) --> adds bg C to list fs_info->unused_bgs deletes bg B sees bg C in the list fs_info->unused_bgs btrfs_remove_chunk(bg C) btrfs_remove_block_group(bg C) --> checks if the block group is in a dirty list, and because it isn't now, it does nothing --> the block group item is deleted from the extent tree --> adds bg C to list transaction->dirty_bgs some task calls btrfs_commit_transaction(t N + 1) commit_cowonly_roots() btrfs_write_dirty_block_groups() --> sees bg C in cur_trans->dirty_bgs --> calls write_one_cache_group() which returns -ENOENT because it did not find the block group item in the extent tree --> transaction aborte with -ENOENT because write_one_cache_group() returned that error So fix this by adding a block group to the list of dirty block groups before adding it to the list of unused block groups. This happened on a stress test using fsstress plus concurrent calls to fallocate 20G and truncate (releasing part of the space allocated with fallocate). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25Btrfs: fix scrub preventing unused block groups from being deletedFilipe Manana
Currently scrub can race with the cleaner kthread when the later attempts to delete an unused block group, and the result is preventing the cleaner kthread from ever deleting later the block group - unless the block group becomes used and unused again. The following diagram illustrates that race: CPU 1 CPU 2 cleaner kthread btrfs_delete_unused_bgs() gets block group X from fs_info->unused_bgs and removes it from that list scrub_enumerate_chunks() searches device tree using its commit root finds device extent for block group X gets block group X from the tree fs_info->block_group_cache_tree (via btrfs_lookup_block_group()) sets bg X to RO sees the block group is already RO and therefore doesn't delete it nor adds it back to unused list So fix this by making scrub add the block group again to the list of unused block groups if the block group is still unused when it finished scrubbing it and it hasn't been removed already. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25Btrfs: fix race between scrub and block group deletionFilipe Manana
Scrub can race with the cleaner kthread deleting block groups that are unused (and with relocation too) leading to a failure with error -EINVAL that gets returned to user space. The following diagram illustrates how it happens: CPU 1 CPU 2 cleaner kthread btrfs_delete_unused_bgs() gets block group X from fs_info->unused_bgs sets block group to RO btrfs_remove_chunk(bg X) deletes device extents scrub_enumerate_chunks() searches device tree using its commit root finds device extent for block group X gets block group X from the tree fs_info->block_group_cache_tree (via btrfs_lookup_block_group()) sets bg X to RO (again) btrfs_remove_block_group(bg X) deletes block group from fs_info->block_group_cache_tree removes extent map from fs_info->mapping_tree scrub_chunk(offset X) searches fs_info->mapping_tree for extent map starting at offset X --> doesn't find any such extent map --> returns -EINVAL and scrub errors out to userspace with -EINVAL Fix this by dealing with an extent map lookup failure as an indicator of block group deletion. Issue reproduced with fstest btrfs/071. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25btrfs: fix rcu warning during device replaceDavid Sterba
The test btrfs/011 triggers a rcu warning Reviewed-by: Anand Jain <anand.jain@oracle.com> =============================== [ INFO: suspicious RCU usage. ] 4.4.0-rc1-default+ #286 Tainted: G W ------------------------------- fs/btrfs/volumes.c:1977 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 4 locks held by btrfs/28786: 0: (&fs_info->dev_replace.lock_finishing_cancel_unmount){+.+...}, at: [<ffffffffa00bc785>] btrfs_dev_replace_finishing+0x45/0xa00 [btrfs] 1: (uuid_mutex){+.+.+.}, at: [<ffffffffa00bc84f>] btrfs_dev_replace_finishing+0x10f/0xa00 [btrfs] 2: (&fs_devs->device_list_mutex){+.+.+.}, at: [<ffffffffa00bc868>] btrfs_dev_replace_finishing+0x128/0xa00 [btrfs] 3: (&fs_info->chunk_mutex){+.+...}, at: [<ffffffffa00bc87d>] btrfs_dev_replace_finishing+0x13d/0xa00 [btrfs] stack backtrace: CPU: 0 PID: 28786 Comm: btrfs Tainted: G W 4.4.0-rc1-default+ #286 Hardware name: Intel Corporation SandyBridge Platform/To be filled by O.E.M., BIOS ASNBCPT1.86C.0031.B00.1006301607 06/30/2010 0000000000000001 ffff8800a07dfb48 ffffffff8141d47b 0000000000000001 0000000000000001 0000000000000000 ffff8801464a4f00 ffff8800a07dfb78 ffffffff810cd883 ffff880146eb9400 ffff8800a3698600 ffff8800a33fe220 Call Trace: [<ffffffff8141d47b>] dump_stack+0x4f/0x74 [<ffffffff810cd883>] lockdep_rcu_suspicious+0x103/0x140 [<ffffffffa0071261>] btrfs_rm_dev_replace_remove_srcdev+0x111/0x130 [btrfs] [<ffffffff810d354d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff81449536>] ? __percpu_counter_sum+0x66/0x80 [<ffffffffa00bcc15>] btrfs_dev_replace_finishing+0x4d5/0xa00 [btrfs] [<ffffffffa00bc96e>] ? btrfs_dev_replace_finishing+0x22e/0xa00 [btrfs] [<ffffffffa00a8795>] ? btrfs_scrub_dev+0x415/0x6d0 [btrfs] [<ffffffffa003ea69>] ? btrfs_start_transaction+0x9/0x20 [btrfs] [<ffffffffa00bda79>] btrfs_dev_replace_start+0x339/0x590 [btrfs] [<ffffffff81196aa5>] ? __might_fault+0x95/0xa0 [<ffffffffa0078638>] btrfs_ioctl_dev_replace+0x118/0x160 [btrfs] [<ffffffff811409c6>] ? stack_trace_call+0x46/0x70 [<ffffffffa007c914>] ? btrfs_ioctl+0x24/0x1770 [btrfs] [<ffffffffa007ce43>] btrfs_ioctl+0x553/0x1770 [btrfs] [<ffffffff811409c6>] ? stack_trace_call+0x46/0x70 [<ffffffff811d6eb1>] ? do_vfs_ioctl+0x21/0x5a0 [<ffffffff811d6f1c>] do_vfs_ioctl+0x8c/0x5a0 [<ffffffff811e3336>] ? __fget_light+0x86/0xb0 [<ffffffff811e3369>] ? __fdget+0x9/0x20 [<ffffffff811d7451>] ? SyS_ioctl+0x21/0x80 [<ffffffff811d7483>] SyS_ioctl+0x53/0x80 [<ffffffff81b1efd7>] entry_SYSCALL_64_fastpath+0x12/0x6f This is because of unprotected use of rcu_dereference in btrfs_scratch_superblocks. We can't add rcu locks around the whole function because we read the superblock. The fix will use the rcu string buffer directly without the rcu locking. Thi is safe as the device will not go away in the meantime. We're holding the device list mutexes. Restructuring the code to narrow down the rcu section turned out to be impossible, we need to call filp_open (through update_dev_time) on the buffer and this could call kmalloc/__might_sleep. We could call kstrdup with GFP_ATOMIC but it's not absolutely necessary. Fixes: 12b1c2637b6e (Btrfs: enhance btrfs_scratch_superblock to scratch all superblocks) Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25btrfs: Continue replace when set_block_ro failedZhaolei
xfstests/011 failed in node with small_size filesystem. Can be reproduced by following script: DEV_LIST="/dev/vdd /dev/vde" DEV_REPLACE="/dev/vdf" do_test() { local mkfs_opt="$1" local size="$2" dmesg -c >/dev/null umount $SCRATCH_MNT &>/dev/null echo mkfs.btrfs -f $mkfs_opt "${DEV_LIST[*]}" mkfs.btrfs -f $mkfs_opt "${DEV_LIST[@]}" || return 1 mount "${DEV_LIST[0]}" $SCRATCH_MNT echo -n "Writing big files" dd if=/dev/urandom of=$SCRATCH_MNT/t0 bs=1M count=1 >/dev/null 2>&1 for ((i = 1; i <= size; i++)); do echo -n . /bin/cp $SCRATCH_MNT/t0 $SCRATCH_MNT/t$i || return 1 done echo echo Start replace btrfs replace start -Bf "${DEV_LIST[0]}" "$DEV_REPLACE" $SCRATCH_MNT || { dmesg return 1 } return 0 } # Set size to value near fs size # for example, 1897 can trigger this bug in 2.6G device. # ./do_test "-d raid1 -m raid1" 1897 System will report replace fail with following warning in dmesg: [ 134.710853] BTRFS: dev_replace from /dev/vdd (devid 1) to /dev/vdf started [ 135.542390] BTRFS: btrfs_scrub_dev(/dev/vdd, 1, /dev/vdf) failed -28 [ 135.543505] ------------[ cut here ]------------ [ 135.544127] WARNING: CPU: 0 PID: 4080 at fs/btrfs/dev-replace.c:428 btrfs_dev_replace_start+0x398/0x440() [ 135.545276] Modules linked in: [ 135.545681] CPU: 0 PID: 4080 Comm: btrfs Not tainted 4.3.0 #256 [ 135.546439] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.2-0-g33fbe13 by qemu-project.org 04/01/2014 [ 135.547798] ffffffff81c5bfcf ffff88003cbb3d28 ffffffff817fe7b5 0000000000000000 [ 135.548774] ffff88003cbb3d60 ffffffff810a88f1 ffff88002b030000 00000000ffffffe4 [ 135.549774] ffff88003c080000 ffff88003c082588 ffff88003c28ab60 ffff88003cbb3d70 [ 135.550758] Call Trace: [ 135.551086] [<ffffffff817fe7b5>] dump_stack+0x44/0x55 [ 135.551737] [<ffffffff810a88f1>] warn_slowpath_common+0x81/0xc0 [ 135.552487] [<ffffffff810a89e5>] warn_slowpath_null+0x15/0x20 [ 135.553211] [<ffffffff81448c88>] btrfs_dev_replace_start+0x398/0x440 [ 135.554051] [<ffffffff81412c3e>] btrfs_ioctl+0x1d2e/0x25c0 [ 135.554722] [<ffffffff8114c7ba>] ? __audit_syscall_entry+0xaa/0xf0 [ 135.555506] [<ffffffff8111ab36>] ? current_kernel_time64+0x56/0xa0 [ 135.556304] [<ffffffff81201e3d>] do_vfs_ioctl+0x30d/0x580 [ 135.557009] [<ffffffff8114c7ba>] ? __audit_syscall_entry+0xaa/0xf0 [ 135.557855] [<ffffffff810011d1>] ? do_audit_syscall_entry+0x61/0x70 [ 135.558669] [<ffffffff8120d1c1>] ? __fget_light+0x61/0x90 [ 135.559374] [<ffffffff81202124>] SyS_ioctl+0x74/0x80 [ 135.559987] [<ffffffff81809857>] entry_SYSCALL_64_fastpath+0x12/0x6f [ 135.560842] ---[ end trace 2a5c1fc3205abbdd ]--- Reason: When big data writen to fs, the whole free space will be allocated for data chunk. And operation as scrub need to set_block_ro(), and when there is only one metadata chunk in system(or other metadata chunks are all full), the function will try to allocate a new chunk, and failed because no space in device. Fix: When set_block_ro failed for metadata chunk, it is not a problem because scrub_lock paused commit_trancaction in same time, and metadata are always cowed, so the on-the-fly writepages will not write data into same place with scrub/replace. Let replace continue in this case is no problem. Tested by above script, and xfstests/011, plus 100 times xfstests/070. Changelog v1->v2: 1: Add detail comments in source and commit-message. 2: Add dmesg detail into commit-message. 3: Limit return value of -ENOSPC to be passed. All suggested by: Filipe Manana <fdmanana@gmail.com> Suggested-by: Filipe Manana <fdmanana@gmail.com> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25btrfs: fix clashing number of the enhanced balance usage filterDavid Sterba
I've accidentally picked an already used number for the enhanced usage filter represented by BTRFS_BALANCE_ARGS_USAGE_RANGE, clashing with BTRFS_BALANCE_ARGS_CONVERT. Introduced during the development phase, no backward compatibility issues. Reported-by: Holger Hoffstätte <holger.hoffstaette@googlemail.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: bc3094673f22 ("btrfs: extend balance filter usage to take minimum and maximum") Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25Btrfs: fix the number of transaction units needed to remove a block groupFilipe Manana
We were using only 1 transaction unit when attempting to delete an unused block group but in reality we need 3 + N units, where N corresponds to the number of stripes. We were accounting only for the addition of the orphan item (for the block group's free space cache inode) but we were not accounting that we need to delete one block group item from the extent tree, one free space item from the tree of tree roots and N device extent items from the device tree. While one unit is not enough, it worked most of the time because for each single unit we are too pessimistic and assume an entire tree path, with the highest possible heigth (8), needs to be COWed with eventual node splits at every possible level in the tree, so there was usually enough reserved space for removing all the items and adding the orphan item. However after adding the orphan item, writepages() can by called by the VM subsystem against the btree inode when we are under memory pressure, which causes writeback to start for the nodes we COWed before, this forces the operation to remove the free space item to COW again some (or all of) the same nodes (in the tree of tree roots). Even without writepages() being called, we could fail with ENOSPC because these items are located in multiple trees and one of them might have a higher heigth and require node/leaf splits at many levels, exhausting all the reserved space before removing all the items and adding the orphan. In the kernel 4.0 release, commit 3d84be799194 ("Btrfs: fix BUG_ON in btrfs_orphan_add() when delete unused block group"), we attempted to fix a BUG_ON due to ENOSPC when trying to add the orphan item by making the cleaner kthread reserve one transaction unit before attempting to remove the block group, but this was not enough. We had a couple user reports still hitting the same BUG_ON after 4.0, like Stefan Priebe's report on a 4.2-rc6 kernel for example: http://www.spinics.net/lists/linux-btrfs/msg46070.html So fix this by reserving all the necessary units of metadata. Reported-by: Stefan Priebe <s.priebe@profihost.ag> Fixes: 3d84be799194 ("Btrfs: fix BUG_ON in btrfs_orphan_add() when delete unused block group") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25Btrfs: use global reserve when deleting unused block group after ENOSPCFilipe Manana
It's possible to reach a state where the cleaner kthread isn't able to start a transaction to delete an unused block group due to lack of enough free metadata space and due to lack of unallocated device space to allocate a new metadata block group as well. If this happens try to use space from the global block group reserve just like we do for unlink operations, so that we don't reach a permanent state where starting a transaction for filesystem operations (file creation, renames, etc) keeps failing with -ENOSPC. Such an unfortunate state was observed on a machine where over a dozen unused data block groups existed and the cleaner kthread was failing to delete them due to ENOSPC error when attempting to start a transaction, and even running balance with a -dusage=0 filter failed with ENOSPC as well. Also unmounting and mounting again the filesystem didn't help. Allowing the cleaner kthread to use the global block reserve to delete the unused data block groups fixed the problem. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25Btrfs: tests: checking for NULL instead of IS_ERR()Dan Carpenter
btrfs_alloc_dummy_root() return an error pointer on failure, it never returns NULL. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25btrfs: fix signed overflows in btrfs_sync_fileDavid Sterba
The calculation of range length in btrfs_sync_file leads to signed overflow. This was caught by PaX gcc SIZE_OVERFLOW plugin. https://forums.grsecurity.net/viewtopic.php?f=1&t=4284 The fsync call passes 0 and LLONG_MAX, the range length does not fit to loff_t and overflows, but the value is converted to u64 so it silently works as expected. The minimal fix is a typecast to u64, switching functions to take (start, end) instead of (start, len) would be more intrusive. Coccinelle script found that there's one more opencoded calculation of the length. <smpl> @@ loff_t start, end; @@ * end - start </smpl> CC: stable@vger.kernel.org Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-13Merge branch 'for-linus-4.4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes and cleanups from Chris Mason: "Some of this got cherry-picked from a github repo this week, but I verified the patches. We have three small scrub cleanups and a collection of fixes" * 'for-linus-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: btrfs: Use fs_info directly in btrfs_delete_unused_bgs btrfs: Fix lost-data-profile caused by balance bg btrfs: Fix lost-data-profile caused by auto removing bg btrfs: Remove len argument from scrub_find_csum btrfs: Reduce unnecessary arguments in scrub_recheck_block btrfs: Use scrub_checksum_data and scrub_checksum_tree_block for scrub_recheck_block_checksum btrfs: Reset sblock->xxx_error stats before calling scrub_recheck_block_checksum btrfs: scrub: setup all fields for sblock_to_check btrfs: scrub: set error stats when tree block spanning stripes Btrfs: fix race when listing an inode's xattrs Btrfs: fix race leading to BUG_ON when running delalloc for nodatacow Btrfs: fix race leading to incorrect item deletion when dropping extents Btrfs: fix sleeping inside atomic context in qgroup rescan worker Btrfs: fix race waiting for qgroup rescan worker btrfs: qgroup: exit the rescan worker during umount Btrfs: fix extent accounting for partial direct IO writes
2015-11-10btrfs: Use fs_info directly in btrfs_delete_unused_bgsZhao Lei
No need to use root->fs_info in btrfs_delete_unused_bgs(), use fs_info directly instead. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-10btrfs: Fix lost-data-profile caused by balance bgZhao Lei
Reproduce: (In integration-4.3 branch) TEST_DEV=(/dev/vdg /dev/vdh) TEST_DIR=/mnt/tmp umount "$TEST_DEV" >/dev/null mkfs.btrfs -f -d raid1 "${TEST_DEV[@]}" mount -o nospace_cache "$TEST_DEV" "$TEST_DIR" btrfs balance start -dusage=0 $TEST_DIR btrfs filesystem usage $TEST_DIR dd if=/dev/zero of="$TEST_DIR"/file count=100 btrfs filesystem usage $TEST_DIR Result: We can see "no data chunk" in first "btrfs filesystem usage": # btrfs filesystem usage $TEST_DIR Overall: ... Metadata,single: Size:8.00MiB, Used:0.00B /dev/vdg 8.00MiB Metadata,RAID1: Size:122.88MiB, Used:112.00KiB /dev/vdg 122.88MiB /dev/vdh 122.88MiB System,single: Size:4.00MiB, Used:0.00B /dev/vdg 4.00MiB System,RAID1: Size:8.00MiB, Used:16.00KiB /dev/vdg 8.00MiB /dev/vdh 8.00MiB Unallocated: /dev/vdg 1.06GiB /dev/vdh 1.07GiB And "data chunks changed from raid1 to single" in second "btrfs filesystem usage": # btrfs filesystem usage $TEST_DIR Overall: ... Data,single: Size:256.00MiB, Used:0.00B /dev/vdh 256.00MiB Metadata,single: Size:8.00MiB, Used:0.00B /dev/vdg 8.00MiB Metadata,RAID1: Size:122.88MiB, Used:112.00KiB /dev/vdg 122.88MiB /dev/vdh 122.88MiB System,single: Size:4.00MiB, Used:0.00B /dev/vdg 4.00MiB System,RAID1: Size:8.00MiB, Used:16.00KiB /dev/vdg 8.00MiB /dev/vdh 8.00MiB Unallocated: /dev/vdg 1.06GiB /dev/vdh 841.92MiB Reason: btrfs balance delete last data chunk in case of no data in the filesystem, then we can see "no data chunk" by "fi usage" command. And when we do write operation to fs, the only available data profile is 0x0, result is all new chunks are allocated single type. Fix: Allocate a data chunk explicitly to ensure we don't lose the raid profile for data. Test: Test by above script, and confirmed the logic by debug output. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-10btrfs: Fix lost-data-profile caused by auto removing bgZhao Lei
Reproduce: (In integration-4.3 branch) TEST_DEV=(/dev/vdg /dev/vdh) TEST_DIR=/mnt/tmp umount "$TEST_DEV" >/dev/null mkfs.btrfs -f -d raid1 "${TEST_DEV[@]}" mount -o nospace_cache "$TEST_DEV" "$TEST_DIR" umount "$TEST_DEV" mount -o nospace_cache "$TEST_DEV" "$TEST_DIR" btrfs filesystem usage $TEST_DIR We can see the data chunk changed from raid1 to single: # btrfs filesystem usage $TEST_DIR Data,single: Size:8.00MiB, Used:0.00B /dev/vdg 8.00MiB # Reason: When a empty filesystem mount with -o nospace_cache, the last data blockgroup will be auto-removed in umount. Then if we mount it again, there is no data chunk in the filesystem, so the only available data profile is 0x0, result is all new chunks are created as single type. Fix: Don't auto-delete last blockgroup for a raid type. Test: Test by above script, and confirmed the logic by debug output. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-10btrfs: Remove len argument from scrub_find_csumZhao Lei
It is useless. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-10btrfs: Reduce unnecessary arguments in scrub_recheck_blockZhao Lei
We don't need pass so many arguments for recheck sblock now, this patch cleans them. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-10btrfs: Use scrub_checksum_data and scrub_checksum_tree_block for ↵Zhao Lei
scrub_recheck_block_checksum We can use existing scrub_checksum_data() and scrub_checksum_tree_block() for scrub_recheck_block_checksum(), instead of write duplicated code. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-10btrfs: Reset sblock->xxx_error stats before calling scrub_recheck_block_checksumZhao Lei
We should reset sblock->xxx_error stats before calling scrub_recheck_block_checksum(). Current code run correctly because all sblock are allocated by k[cz]alloc(), and the error stats are not got changed. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-10btrfs: scrub: setup all fields for sblock_to_checkZhao Lei
scrub_setup_recheck_block() isn't setup all necessary fields for sblock_to_check because history reason. So current code need more arguments in severial functions, and more local variables, just to passing these lacked values to necessary place. This patch setup above fields to sblock_to_check in scrub_setup_recheck_block(), for: 1: more cleanup for function arg, local variable 2: to make sblock_to_check complete, then we can use sblock_to_check without concern about some uninitialized member. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-10btrfs: scrub: set error stats when tree block spanning stripesZhao Lei
It is better to show error stats to user when we found tree block spanning stripes. On a btrfs created by old version of btrfs-convert: Before patch: # btrfs scrub start -B /dev/vdh scrub done for 8b342d35-2904-41ab-b3cb-2f929709cf47 scrub started at Tue Aug 25 21:19:09 2015 and finished after 00:00:00 total bytes scrubbed: 53.54MiB with 0 errors # dmesg ... [ 128.711434] BTRFS error (device vdh): scrub: tree block 27054080 spanning stripes, ignored. logical=27000832 [ 128.712744] BTRFS error (device vdh): scrub: tree block 27054080 spanning stripes, ignored. logical=27066368 ... After patch: # btrfs scrub start -B /dev/vdh scrub done for ff7f844b-7a4e-4b1a-88a9-8252ab25be1b scrub started at Tue Aug 25 21:42:29 2015 and finished after 00:00:00 total bytes scrubbed: 53.60MiB with 2 errors error details: corrected errors: 0, uncorrectable errors: 2, unverified errors: 0 ERROR: There are uncorrectable errors. # dmesg ...omit... # Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-09fs/btrfs/inode.c: remove unnecessary new_valid_dev() checkYaowei Bai
new_valid_dev() always returns 1, so the !new_valid_dev() check is not needed. Remove it. Signed-off-by: Yaowei Bai <bywxiaobai@163.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <jbacik@fb.com> Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-09Btrfs: fix race when listing an inode's xattrsFilipe Manana
When listing a inode's xattrs we have a time window where we race against a concurrent operation for adding a new hard link for our inode that makes us not return any xattr to user space. In order for this to happen, the first xattr of our inode needs to be at slot 0 of a leaf and the previous leaf must still have room for an inode ref (or extref) item, and this can happen because an inode's listxattrs callback does not lock the inode's i_mutex (nor does the VFS does it for us), but adding a hard link to an inode makes the VFS lock the inode's i_mutex before calling the inode's link callback. If we have the following leafs: Leaf X (has N items) Leaf Y [ ... (257 INODE_ITEM 0) (257 INODE_REF 256) ] [ (257 XATTR_ITEM 12345), ... ] slot N - 2 slot N - 1 slot 0 The race illustrated by the following sequence diagram is possible: CPU 1 CPU 2 btrfs_listxattr() searches for key (257 XATTR_ITEM 0) gets path with path->nodes[0] == leaf X and path->slots[0] == N because path->slots[0] is >= btrfs_header_nritems(leaf X), it calls btrfs_next_leaf() btrfs_next_leaf() releases the path adds key (257 INODE_REF 666) to the end of leaf X (slot N), and leaf X now has N + 1 items searches for the key (257 INODE_REF 256), with path->keep_locks == 1, because that is the last key it saw in leaf X before releasing the path ends up at leaf X again and it verifies that the key (257 INODE_REF 256) is no longer the last key in leaf X, so it returns with path->nodes[0] == leaf X and path->slots[0] == N, pointing to the new item with key (257 INODE_REF 666) btrfs_listxattr's loop iteration sees that the type of the key pointed by the path is different from the type BTRFS_XATTR_ITEM_KEY and so it breaks the loop and stops looking for more xattr items --> the application doesn't get any xattr listed for our inode So fix this by breaking the loop only if the key's type is greater than BTRFS_XATTR_ITEM_KEY and skip the current key if its type is smaller. Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com>
2015-11-09Btrfs: fix race leading to BUG_ON when running delalloc for nodatacowFilipe Manana
If we are using the NO_HOLES feature, we have a tiny time window when running delalloc for a nodatacow inode where we can race with a concurrent link or xattr add operation leading to a BUG_ON. This happens because at run_delalloc_nocow() we end up casting a leaf item of type BTRFS_INODE_[REF|EXTREF]_KEY or of type BTRFS_XATTR_ITEM_KEY to a file extent item (struct btrfs_file_extent_item) and then analyse its extent type field, which won't match any of the expected extent types (values BTRFS_FILE_EXTENT_[REG|PREALLOC|INLINE]) and therefore trigger an explicit BUG_ON(1). The following sequence diagram shows how the race happens when running a no-cow dellaloc range [4K, 8K[ for inode 257 and we have the following neighbour leafs: Leaf X (has N items) Leaf Y [ ... (257 INODE_ITEM 0) (257 INODE_REF 256) ] [ (257 EXTENT_DATA 8192), ... ] slot N - 2 slot N - 1 slot 0 (Note the implicit hole for inode 257 regarding the [0, 8K[ range) CPU 1 CPU 2 run_dealloc_nocow() btrfs_lookup_file_extent() --> searches for a key with value (257 EXTENT_DATA 4096) in the fs/subvol tree --> returns us a path with path->nodes[0] == leaf X and path->slots[0] == N because path->slots[0] is >= btrfs_header_nritems(leaf X), it calls btrfs_next_leaf() btrfs_next_leaf() --> releases the path hard link added to our inode, with key (257 INODE_REF 500) added to the end of leaf X, so leaf X now has N + 1 keys --> searches for the key (257 INODE_REF 256), because it was the last key in leaf X before it released the path, with path->keep_locks set to 1 --> ends up at leaf X again and it verifies that the key (257 INODE_REF 256) is no longer the last key in the leaf, so it returns with path->nodes[0] == leaf X and path->slots[0] == N, pointing to the new item with key (257 INODE_REF 500) the loop iteration of run_dealloc_nocow() does not break out the loop and continues because the key referenced in the path at path->nodes[0] and path->slots[0] is for inode 257, its type is < BTRFS_EXTENT_DATA_KEY and its offset (500) is less then our delalloc range's end (8192) the item pointed by the path, an inode reference item, is (incorrectly) interpreted as a file extent item and we get an invalid extent type, leading to the BUG_ON(1): if (extent_type == BTRFS_FILE_EXTENT_REG || extent_type == BTRFS_FILE_EXTENT_PREALLOC) { (...) } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { (...) } else { BUG_ON(1) } The same can happen if a xattr is added concurrently and ends up having a key with an offset smaller then the delalloc's range end. So fix this by skipping keys with a type smaller than BTRFS_EXTENT_DATA_KEY. Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com>
2015-11-08Btrfs: fix race leading to incorrect item deletion when dropping extentsFilipe Manana
While running a stress test I got the following warning triggered: [191627.672810] ------------[ cut here ]------------ [191627.673949] WARNING: CPU: 8 PID: 8447 at fs/btrfs/file.c:779 __btrfs_drop_extents+0x391/0xa50 [btrfs]() (...) [191627.701485] Call Trace: [191627.702037] [<ffffffff8145f077>] dump_stack+0x4f/0x7b [191627.702992] [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2 [191627.704091] [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb [191627.705380] [<ffffffffa0664499>] ? __btrfs_drop_extents+0x391/0xa50 [btrfs] [191627.706637] [<ffffffff8104b46d>] warn_slowpath_null+0x1a/0x1c [191627.707789] [<ffffffffa0664499>] __btrfs_drop_extents+0x391/0xa50 [btrfs] [191627.709155] [<ffffffff8115663c>] ? cache_alloc_debugcheck_after.isra.32+0x171/0x1d0 [191627.712444] [<ffffffff81155007>] ? kmemleak_alloc_recursive.constprop.40+0x16/0x18 [191627.714162] [<ffffffffa06570c9>] insert_reserved_file_extent.constprop.40+0x83/0x24e [btrfs] [191627.715887] [<ffffffffa065422b>] ? start_transaction+0x3bb/0x610 [btrfs] [191627.717287] [<ffffffffa065b604>] btrfs_finish_ordered_io+0x273/0x4e2 [btrfs] [191627.728865] [<ffffffffa065b888>] finish_ordered_fn+0x15/0x17 [btrfs] [191627.730045] [<ffffffffa067d688>] normal_work_helper+0x14c/0x32c [btrfs] [191627.731256] [<ffffffffa067d96a>] btrfs_endio_write_helper+0x12/0x14 [btrfs] [191627.732661] [<ffffffff81061119>] process_one_work+0x24c/0x4ae [191627.733822] [<ffffffff810615b0>] worker_thread+0x206/0x2c2 [191627.734857] [<ffffffff810613aa>] ? process_scheduled_works+0x2f/0x2f [191627.736052] [<ffffffff810613aa>] ? process_scheduled_works+0x2f/0x2f [191627.737349] [<ffffffff810669a6>] kthread+0xef/0xf7 [191627.738267] [<ffffffff810f3b3a>] ? time_hardirqs_on+0x15/0x28 [191627.739330] [<ffffffff810668b7>] ? __kthread_parkme+0xad/0xad [191627.741976] [<ffffffff81465592>] ret_from_fork+0x42/0x70 [191627.743080] [<ffffffff810668b7>] ? __kthread_parkme+0xad/0xad [191627.744206] ---[ end trace bbfddacb7aaada8d ]--- $ cat -n fs/btrfs/file.c 691 int __btrfs_drop_extents(struct btrfs_trans_handle *trans, (...) 758 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 759 if (key.objectid > ino || 760 key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end) 761 break; 762 763 fi = btrfs_item_ptr(leaf, path->slots[0], 764 struct btrfs_file_extent_item); 765 extent_type = btrfs_file_extent_type(leaf, fi); 766 767 if (extent_type == BTRFS_FILE_EXTENT_REG || 768 extent_type == BTRFS_FILE_EXTENT_PREALLOC) { (...) 774 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { (...) 778 } else { 779 WARN_ON(1); 780 extent_end = search_start; 781 } (...) This happened because the item we were processing did not match a file extent item (its key type != BTRFS_EXTENT_DATA_KEY), and even on this case we cast the item to a struct btrfs_file_extent_item pointer and then find a type field value that does not match any of the expected values (BTRFS_FILE_EXTENT_[REG|PREALLOC|INLINE]). This scenario happens due to a tiny time window where a race can happen as exemplified below. For example, consider the following scenario where we're using the NO_HOLES feature and we have the following two neighbour leafs: Leaf X (has N items) Leaf Y [ ... (257 INODE_ITEM 0) (257 INODE_REF 256) ] [ (257 EXTENT_DATA 8192), ... ] slot N - 2 slot N - 1 slot 0 Our inode 257 has an implicit hole in the range [0, 8K[ (implicit rather than explicit because NO_HOLES is enabled). Now if our inode has an ordered extent for the range [4K, 8K[ that is finishing, the following can happen: CPU 1 CPU 2 btrfs_finish_ordered_io() insert_reserved_file_extent() __btrfs_drop_extents() Searches for the key (257 EXTENT_DATA 4096) through btrfs_lookup_file_extent() Key not found and we get a path where path->nodes[0] == leaf X and path->slots[0] == N Because path->slots[0] is >= btrfs_header_nritems(leaf X), we call btrfs_next_leaf() btrfs_next_leaf() releases the path inserts key (257 INODE_REF 4096) at the end of leaf X, leaf X now has N + 1 keys, and the new key is at slot N btrfs_next_leaf() searches for key (257 INODE_REF 256), with path->keep_locks set to 1, because it was the last key it saw in leaf X finds it in leaf X again and notices it's no longer the last key of the leaf, so it returns 0 with path->nodes[0] == leaf X and path->slots[0] == N (which is now < btrfs_header_nritems(leaf X)), pointing to the new key (257 INODE_REF 4096) __btrfs_drop_extents() casts the item at path->nodes[0], slot path->slots[0], to a struct btrfs_file_extent_item - it does not skip keys for the target inode with a type less than BTRFS_EXTENT_DATA_KEY (BTRFS_INODE_REF_KEY < BTRFS_EXTENT_DATA_KEY) sees a bogus value for the type field triggering the WARN_ON in the trace shown above, and sets extent_end = search_start (4096) does the if-then-else logic to fixup 0 length extent items created by a past bug from hole punching: if (extent_end == key.offset && extent_end >= search_start) goto delete_extent_item; that evaluates to true and it ends up deleting the key pointed to by path->slots[0], (257 INODE_REF 4096), from leaf X The same could happen for example for a xattr that ends up having a key with an offset value that matches search_start (very unlikely but not impossible). So fix this by ensuring that keys smaller than BTRFS_EXTENT_DATA_KEY are skipped, never casted to struct btrfs_file_extent_item and never deleted by accident. Also protect against the unexpected case of getting a key for a lower inode number by skipping that key and issuing a warning. Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com>
2015-11-07Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge second patch-bomb from Andrew Morton: - most of the rest of MM - procfs - lib/ updates - printk updates - bitops infrastructure tweaks - checkpatch updates - nilfs2 update - signals - various other misc bits: coredump, seqfile, kexec, pidns, zlib, ipc, dma-debug, dma-mapping, ... * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (102 commits) ipc,msg: drop dst nil validation in copy_msg include/linux/zutil.h: fix usage example of zlib_adler32() panic: release stale console lock to always get the logbuf printed out dma-debug: check nents in dma_sync_sg* dma-mapping: tidy up dma_parms default handling pidns: fix set/getpriority and ioprio_set/get in PRIO_USER mode kexec: use file name as the output message prefix fs, seqfile: always allow oom killer seq_file: reuse string_escape_str() fs/seq_file: use seq_* helpers in seq_hex_dump() coredump: change zap_threads() and zap_process() to use for_each_thread() coredump: ensure all coredumping tasks have SIGNAL_GROUP_COREDUMP signal: remove jffs2_garbage_collect_thread()->allow_signal(SIGCONT) signal: introduce kernel_signal_stop() to fix jffs2_garbage_collect_thread() signal: turn dequeue_signal_lock() into kernel_dequeue_signal() signals: kill block_all_signals() and unblock_all_signals() nilfs2: fix gcc uninitialized-variable warnings in powerpc build nilfs2: fix gcc unused-but-set-variable warnings MAINTAINERS: nilfs2: add header file for tracing nilfs2: add tracepoints for analyzing reading and writing metadata files ...
2015-11-06mm, fs: introduce mapping_gfp_constraint()Michal Hocko
There are many places which use mapping_gfp_mask to restrict a more generic gfp mask which would be used for allocations which are not directly related to the page cache but they are performed in the same context. Let's introduce a helper function which makes the restriction explicit and easier to track. This patch doesn't introduce any functional changes. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Michal Hocko <mhocko@suse.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06mm, page_alloc: distinguish between being unable to sleep, unwilling to ↵Mel Gorman
sleep and avoiding waking kswapd __GFP_WAIT has been used to identify atomic context in callers that hold spinlocks or are in interrupts. They are expected to be high priority and have access one of two watermarks lower than "min" which can be referred to as the "atomic reserve". __GFP_HIGH users get access to the first lower watermark and can be called the "high priority reserve". Over time, callers had a requirement to not block when fallback options were available. Some have abused __GFP_WAIT leading to a situation where an optimisitic allocation with a fallback option can access atomic reserves. This patch uses __GFP_ATOMIC to identify callers that are truely atomic, cannot sleep and have no alternative. High priority users continue to use __GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify callers that want to wake kswapd for background reclaim. __GFP_WAIT is redefined as a caller that is willing to enter direct reclaim and wake kswapd for background reclaim. This patch then converts a number of sites o __GFP_ATOMIC is used by callers that are high priority and have memory pools for those requests. GFP_ATOMIC uses this flag. o Callers that have a limited mempool to guarantee forward progress clear __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall into this category where kswapd will still be woken but atomic reserves are not used as there is a one-entry mempool to guarantee progress. o Callers that are checking if they are non-blocking should use the helper gfpflags_allow_blocking() where possible. This is because checking for __GFP_WAIT as was done historically now can trigger false positives. Some exceptions like dm-crypt.c exist where the code intent is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to flag manipulations. o Callers that built their own GFP flags instead of starting with GFP_KERNEL and friends now also need to specify __GFP_KSWAPD_RECLAIM. The first key hazard to watch out for is callers that removed __GFP_WAIT and was depending on access to atomic reserves for inconspicuous reasons. In some cases it may be appropriate for them to use __GFP_HIGH. The second key hazard is callers that assembled their own combination of GFP flags instead of starting with something like GFP_KERNEL. They may now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless if it's missed in most cases as other activity will wake kswapd. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Vitaly Wool <vitalywool@gmail.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06Merge branch 'for-linus-4.4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs updates from Chris Mason: "We have a lot of subvolume quota improvements in here, along with big piles of cleanups from Dave Sterba and Anand Jain and others. Josef pitched in a batch of allocator fixes based on production use here at FB. We found that mount -o ssd_spread greatly improved our performance on hardware raid5/6, but it exposed some CPU bottlenecks in the allocator. These patches make a huge difference" * 'for-linus-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (100 commits) Btrfs: fix hole punching when using the no-holes feature Btrfs: find_free_extent: Do not erroneously skip LOOP_CACHING_WAIT state btrfs: Fix a data space underflow warning btrfs: qgroup: Fix a rebase bug which will cause qgroup double free btrfs: qgroup: Fix a race in delayed_ref which leads to abort trans btrfs: clear PF_NOFREEZE in cleaner_kthread() btrfs: qgroup: Don't copy extent buffer to do qgroup rescan btrfs: add balance filters limits, stripes and usage to supported mask btrfs: extend balance filter usage to take minimum and maximum btrfs: add balance filter for stripes btrfs: extend balance filter limit to take minimum and maximum btrfs: fix use after free iterating extrefs btrfs: check unsupported filters in balance arguments Btrfs: fix regression running delayed references when using qgroups Btrfs: fix regression when running delayed references Btrfs: don't do extra bitmap search in one bit case Btrfs: keep track of largest extent in bitmaps Btrfs: don't keep trying to build clusters if we are fragmented Btrfs: cut down on loops through the allocator Btrfs: don't continue setting up space cache when enospc ...
2015-11-05Btrfs: fix sleeping inside atomic context in qgroup rescan workerFilipe Manana
We are holding a btree path with spinning locks and then we attempt to clone an extent buffer, which calls kmem_cache_alloc() and this function can sleep, causing the following trace to be reported on a debug kernel: [107118.218536] BUG: sleeping function called from invalid context at mm/slab.c:2871 [107118.224110] in_atomic(): 1, irqs_disabled(): 0, pid: 19148, name: kworker/u32:3 [107118.226120] INFO: lockdep is turned off. [107118.226843] Preemption disabled at:[<ffffffffa05ffa22>] btrfs_clear_lock_blocking_rw+0x96/0xea [btrfs] [107118.229175] CPU: 3 PID: 19148 Comm: kworker/u32:3 Tainted: G W 4.3.0-rc5-btrfs-next-17+ #1 [107118.231326] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [107118.233687] Workqueue: btrfs-qgroup-rescan btrfs_qgroup_rescan_helper [btrfs] [107118.236835] 0000000000000000 ffff880424bf3b78 ffffffff812566f4 0000000000000000 [107118.238369] ffff880424bf3ba0 ffffffff81070664 ffffffff817f1cd5 0000000000000b37 [107118.239769] 0000000000000000 ffff880424bf3bc8 ffffffff8107070a 0000000000008850 [107118.241244] Call Trace: [107118.241729] [<ffffffff812566f4>] dump_stack+0x4e/0x79 [107118.242602] [<ffffffff81070664>] ___might_sleep+0x23a/0x241 [107118.243586] [<ffffffff8107070a>] __might_sleep+0x9f/0xa6 [107118.244532] [<ffffffff8115af70>] cache_alloc_debugcheck_before+0x25/0x36 [107118.245939] [<ffffffff8115d52b>] kmem_cache_alloc+0x50/0x215 [107118.246930] [<ffffffffa05e627e>] __alloc_extent_buffer+0x2a/0x11f [btrfs] [107118.248121] [<ffffffffa05ecb1a>] btrfs_clone_extent_buffer+0x3d/0xdd [btrfs] [107118.249451] [<ffffffffa06239ea>] btrfs_qgroup_rescan_worker+0x16d/0x434 [btrfs] [107118.250755] [<ffffffff81087481>] ? arch_local_irq_save+0x9/0xc [107118.251754] [<ffffffffa05f7952>] normal_work_helper+0x14c/0x32a [btrfs] [107118.252899] [<ffffffffa05f7952>] ? normal_work_helper+0x14c/0x32a [btrfs] [107118.254195] [<ffffffffa05f7c82>] btrfs_qgroup_rescan_helper+0x12/0x14 [btrfs] [107118.255436] [<ffffffff81063b23>] process_one_work+0x24a/0x4ac [107118.263690] [<ffffffff81064285>] worker_thread+0x206/0x2c2 [107118.264888] [<ffffffff8106407f>] ? rescuer_thread+0x2cb/0x2cb [107118.267413] [<ffffffff8106904d>] kthread+0xef/0xf7 [107118.268417] [<ffffffff81068f5e>] ? kthread_parkme+0x24/0x24 [107118.269505] [<ffffffff8147d10f>] ret_from_fork+0x3f/0x70 [107118.270491] [<ffffffff81068f5e>] ? kthread_parkme+0x24/0x24 So just use blocking locks for our path to solve this. This fixes the patch titled: "btrfs: qgroup: Don't copy extent buffer to do qgroup rescan" Signed-off-by: Filipe Manana <fdmanana@suse.com>