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2018-10-15btrfs: Make btrfs_find_device_by_path return struct btrfs_deviceNikolay Borisov1-12/+13
Currently this function returns an error code as well as uses one of its arguments as a return value for struct btrfs_device. Change the function so that it returns btrfs_device directly and use the usual "encode error in pointer" mechanics if something goes wrong. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: fix error handling in free_log_treeJeff Mahoney1-3/+6
When we hit an I/O error in free_log_tree->walk_log_tree during file system shutdown we can crash due to there not being a valid transaction handle. Use btrfs_handle_fs_error when there's no transaction handle to use. BUG: unable to handle kernel NULL pointer dereference at 0000000000000060 IP: free_log_tree+0xd2/0x140 [btrfs] PGD 0 P4D 0 Oops: 0000 [#1] SMP DEBUG_PAGEALLOC PTI Modules linked in: <modules> CPU: 2 PID: 23544 Comm: umount Tainted: G W 4.12.14-kvmsmall #9 SLE15 (unreleased) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 task: ffff96bfd3478880 task.stack: ffffa7cf40d78000 RIP: 0010:free_log_tree+0xd2/0x140 [btrfs] RSP: 0018:ffffa7cf40d7bd10 EFLAGS: 00010282 RAX: 00000000fffffffb RBX: 00000000fffffffb RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffff96c02f07d4c8 RDI: 0000000000000282 RBP: ffff96c013cf1000 R08: ffff96c02f07d4c8 R09: ffff96c02f07d4d0 R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000000 R13: ffff96c005e800c0 R14: ffffa7cf40d7bdb8 R15: 0000000000000000 FS: 00007f17856bcfc0(0000) GS:ffff96c03f600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000060 CR3: 0000000045ed6002 CR4: 00000000003606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? wait_for_writer+0xb0/0xb0 [btrfs] btrfs_free_log+0x17/0x30 [btrfs] btrfs_drop_and_free_fs_root+0x9a/0xe0 [btrfs] btrfs_free_fs_roots+0xc0/0x130 [btrfs] ? wait_for_completion+0xf2/0x100 close_ctree+0xea/0x2e0 [btrfs] ? kthread_stop+0x161/0x260 generic_shutdown_super+0x6c/0x120 kill_anon_super+0xe/0x20 btrfs_kill_super+0x13/0x100 [btrfs] deactivate_locked_super+0x3f/0x70 cleanup_mnt+0x3b/0x70 task_work_run+0x78/0x90 exit_to_usermode_loop+0x77/0xa6 do_syscall_64+0x1c5/0x1e0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f1784f90827 RSP: 002b:00007ffdeeb03118 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000556a60c62970 RCX: 00007f1784f90827 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556a60c62b50 RBP: 0000000000000000 R08: 0000000000000005 R09: 00000000ffffffff R10: 0000556a60c63900 R11: 0000000000000246 R12: 0000556a60c62b50 R13: 00007f17854a81c4 R14: 0000000000000000 R15: 0000000000000000 RIP: free_log_tree+0xd2/0x140 [btrfs] RSP: ffffa7cf40d7bd10 CR2: 0000000000000060 Fixes: 681ae50917df9 ("Btrfs: cleanup reserved space when freeing tree log on error") CC: <stable@vger.kernel.org> # v3.13 Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: remove redundant variable from btrfs_cross_ref_existMisono Tomohiro1-11/+2
Since commit d7df2c796d7e ("Btrfs attach delayed ref updates to delayed ref heads"), check_delayed_ref() won't return -ENOENT. In btrfs_cross_ref_exist(), two variables 'ret' and 'ret2' are originally used to handle -ENOENT error case. Since the code is not needed anymore, let's just remove 'ret2'. Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15Btrfs: set leave_spinning in btrfs_get_extentLiu Bo1-0/+8
Unless it's going to read inline extents from btree leaf to page, btrfs_get_extent won't sleep during the period of holding path lock. This sets leave_spinning at first and sets path to blocking mode right before reading inline extent if that's the case. The benefit is that a path in spinning mode typically has lower impact (faster) on waiters rather than that in the blocking mode. Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15Btrfs: fix alignment in declaration and prototype of btrfs_get_extentLiu Bo2-5/+5
This fixes btrfs_get_extent to be consistent with our existing declaration style. Note: For the record, indentation styles that are accepted are both, aligning under the opening ( and tab or double tab indentation on the next line. Preferrably not spliting the type or long expressions in the argument lists. Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> [ add note ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: remove unused pointer 'tree' in btrfs_submit_compressed_readColin Ian King1-2/+0
Pointer 'tree' is being assigned but is never used hence it is redundant and can be removed. This is a leftover from cleanup patch 00032d38eaa89c76de7 ("btrfs: drop extent_io_ops::merge_bio_hook callback"). Cleans up clang warning: warning: variable 'tree' set but not used [-Wunused-but-set-variable] Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: remove unused pointer inode in relink_file_extentsColin Ian King1-3/+0
Pointer inode is being assigned but is never used hence it is redundant and can be removed. It's been unused since the introduction in 38c227d87c49a ("Btrfs: snapshot-aware defrag"). Cleans up clang warning: variable ‘inode’ set but not used [-Wunused-but-set-variable] Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: defrag: use btrfs_mod_outstanding_extents in cluster_pages_for_defragSu Yue1-1/+1
Since commit 8b62f87bad9c ("Btrfs: rework outstanding_extents"), manual operations of outstanding_extent in btrfs_inode are replaced by btrfs_mod_outstanding_extents(). The one in cluster_pages_for_defrag seems to be lost, so replace it of btrfs_mod_outstanding_extents(). Fixes: 8b62f87bad9c ("Btrfs: rework outstanding_extents") Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15Btrfs: remove confusing tracepoint in btrfs_add_reserved_bytesLiu Bo1-4/+0
Here we're not releasing any space, but transferring bytes from ->bytes_may_use to ->bytes_reserved. The last change to the code in commit 18513091af9483ba8 ("btrfs: update btrfs_space_info's bytes_may_use timely") removed a conditional tracepoint and the logic changed too but the tracepiont remained. Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: free path at an earlier point in btrfs_get_extentLiu Bo1-1/+1
trace_btrfs_get_extent() has nothing to do with path, place btrfs_free_path ahead so that we can unlock path on error. Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15Btrfs: use next_state in find_first_extent_bitLiu Bo1-6/+1
As next_state() is already defined to get the next state, use it in find_first_extent_bit. No functional changes. Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: locking: Add extra check in btrfs_init_new_buffer() to avoid deadlockQu Wenruo1-0/+13
[BUG] For certain crafted image, whose csum root leaf has missing backref, if we try to trigger write with data csum, it could cause deadlock with the following kernel WARN_ON(): WARNING: CPU: 1 PID: 41 at fs/btrfs/locking.c:230 btrfs_tree_lock+0x3e2/0x400 CPU: 1 PID: 41 Comm: kworker/u4:1 Not tainted 4.18.0-rc1+ #8 Workqueue: btrfs-endio-write btrfs_endio_write_helper RIP: 0010:btrfs_tree_lock+0x3e2/0x400 Call Trace: btrfs_alloc_tree_block+0x39f/0x770 __btrfs_cow_block+0x285/0x9e0 btrfs_cow_block+0x191/0x2e0 btrfs_search_slot+0x492/0x1160 btrfs_lookup_csum+0xec/0x280 btrfs_csum_file_blocks+0x2be/0xa60 add_pending_csums+0xaf/0xf0 btrfs_finish_ordered_io+0x74b/0xc90 finish_ordered_fn+0x15/0x20 normal_work_helper+0xf6/0x500 btrfs_endio_write_helper+0x12/0x20 process_one_work+0x302/0x770 worker_thread+0x81/0x6d0 kthread+0x180/0x1d0 ret_from_fork+0x35/0x40 [CAUSE] That crafted image has missing backref for csum tree root leaf. And when we try to allocate new tree block, since there is no EXTENT/METADATA_ITEM for csum tree root, btrfs consider it's free slot and use it. The extent tree of the image looks like: Normal image | This fuzzed image ----------------------------------+-------------------------------- BG 29360128 | BG 29360128 One empty slot | One empty slot 29364224: backref to UUID tree | 29364224: backref to UUID tree Two empty slots | Two empty slots 29376512: backref to CSUM tree | One empty slot (bad type) <<< 29380608: backref to D_RELOC tree | 29380608: backref to D_RELOC tree ... | ... Since bytenr 29376512 has no METADATA/EXTENT_ITEM, when btrfs try to alloc tree block, it's an valid slot for btrfs. And for finish_ordered_write, when we need to insert csum, we try to CoW csum tree root. By accident, empty slots at bytenr BG_OFFSET, BG_OFFSET + 8K, BG_OFFSET + 12K is already used by tree block COW for other trees, the next empty slot is BG_OFFSET + 16K, which should be the backref for CSUM tree. But due to the bad type, btrfs can recognize it and still consider it as an empty slot, and will try to use it for csum tree CoW. Then in the following call trace, we will try to lock the new tree block, which turns out to be the old csum tree root which is already locked: btrfs_search_slot() called on csum tree root, which is at 29376512 |- btrfs_cow_block() |- btrfs_set_lock_block() | |- Now locks tree block 29376512 (old csum tree root) |- __btrfs_cow_block() |- btrfs_alloc_tree_block() |- btrfs_reserve_extent() | Now it returns tree block 29376512, which extent tree | shows its empty slot, but it's already hold by csum tree |- btrfs_init_new_buffer() |- btrfs_tree_lock() | Triggers WARN_ON(eb->lock_owner == current->pid) |- wait_event() Wait lock owner to release the lock, but it's locked by ourself, so it will deadlock [FIX] This patch will do the lock_owner and current->pid check at btrfs_init_new_buffer(). So above deadlock can be avoided. Since such problem can only happen in crafted image, we will still trigger kernel warning for later aborted transaction, but with a little more meaningful warning message. Link: https://bugzilla.kernel.org/show_bug.cgi?id=200405 Reported-by: Xu Wen <wen.xu@gatech.edu> CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: Handle owner mismatch gracefully when walking up treeQu Wenruo2-7/+13
[BUG] When mounting certain crafted image, btrfs will trigger kernel BUG_ON() when trying to recover balance: kernel BUG at fs/btrfs/extent-tree.c:8956! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 1 PID: 662 Comm: mount Not tainted 4.18.0-rc1-custom+ #10 RIP: 0010:walk_up_proc+0x336/0x480 [btrfs] RSP: 0018:ffffb53540c9b890 EFLAGS: 00010202 Call Trace: walk_up_tree+0x172/0x1f0 [btrfs] btrfs_drop_snapshot+0x3a4/0x830 [btrfs] merge_reloc_roots+0xe1/0x1d0 [btrfs] btrfs_recover_relocation+0x3ea/0x420 [btrfs] open_ctree+0x1af3/0x1dd0 [btrfs] btrfs_mount_root+0x66b/0x740 [btrfs] mount_fs+0x3b/0x16a vfs_kern_mount.part.9+0x54/0x140 btrfs_mount+0x16d/0x890 [btrfs] mount_fs+0x3b/0x16a vfs_kern_mount.part.9+0x54/0x140 do_mount+0x1fd/0xda0 ksys_mount+0xba/0xd0 __x64_sys_mount+0x21/0x30 do_syscall_64+0x60/0x210 entry_SYSCALL_64_after_hwframe+0x49/0xbe [CAUSE] Extent tree corruption. In this particular case, reloc tree root's owner is DATA_RELOC_TREE (should be TREE_RELOC), thus its backref is corrupted and we failed the owner check in walk_up_tree(). [FIX] It's pretty hard to take care of every extent tree corruption, but at least we can remove such BUG_ON() and exit more gracefully. And since in this particular image, DATA_RELOC_TREE and TREE_RELOC share the same root (which is obviously invalid), we needs to make __del_reloc_root() more robust to detect such invalid sharing to avoid possible NULL dereference as root->node can be NULL in this case. Link: https://bugzilla.kernel.org/show_bug.cgi?id=200411 Reported-by: Xu Wen <wen.xu@gatech.edu> CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: change btrfs_pin_log_trans to return voidzhong jiang2-5/+2
btrfs_pin_log_trans defines the variable "ret" for return value, but it is not modified after initialization. Further, I find that none of the callers do handles the return value, so it is safe to drop the unneeded "ret" and make it return void. Signed-off-by: zhong jiang <zhongjiang@huawei.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: change btrfs_free_reserved_bytes to return voidzhong jiang1-4/+2
btrfs_free_reserved_bytes uses the variable "ret" for return value, but it is not modified after initialzation. Further, I find that any of the callers do not handle the return value, so it is safe to drop the unneeded "ret" and return void. There are no callees that would need the function to handle or pass the value either. Signed-off-by: zhong jiang <zhongjiang@huawei.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15Btrfs: remove always true if branch in btrfs_get_extentLiu Bo1-10/+6
@path is always NULL when it comes to the if branch. Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: qgroup: Dirty all qgroups before rescanQu Wenruo1-0/+1
[BUG] In the following case, rescan won't zero out the number of qgroup 1/0: $ mkfs.btrfs -fq $DEV $ mount $DEV /mnt $ btrfs quota enable /mnt $ btrfs qgroup create 1/0 /mnt $ btrfs sub create /mnt/sub $ btrfs qgroup assign 0/257 1/0 /mnt $ dd if=/dev/urandom of=/mnt/sub/file bs=1k count=1000 $ btrfs sub snap /mnt/sub /mnt/snap $ btrfs quota rescan -w /mnt $ btrfs qgroup show -pcre /mnt qgroupid rfer excl max_rfer max_excl parent child -------- ---- ---- -------- -------- ------ ----- 0/5 16.00KiB 16.00KiB none none --- --- 0/257 1016.00KiB 16.00KiB none none 1/0 --- 0/258 1016.00KiB 16.00KiB none none --- --- 1/0 1016.00KiB 16.00KiB none none --- 0/257 So far so good, but: $ btrfs qgroup remove 0/257 1/0 /mnt WARNING: quotas may be inconsistent, rescan needed $ btrfs quota rescan -w /mnt $ btrfs qgroup show -pcre /mnt qgoupid rfer excl max_rfer max_excl parent child -------- ---- ---- -------- -------- ------ ----- 0/5 16.00KiB 16.00KiB none none --- --- 0/257 1016.00KiB 16.00KiB none none --- --- 0/258 1016.00KiB 16.00KiB none none --- --- 1/0 1016.00KiB 16.00KiB none none --- --- ^^^^^^^^^^ ^^^^^^^^ not cleared [CAUSE] Before rescan we call qgroup_rescan_zero_tracking() to zero out all qgroups' accounting numbers. However we don't mark all qgroups dirty, but rely on rescan to do so. If we have any high level qgroup without children, it won't be marked dirty during rescan, since we cannot reach that qgroup. This will cause QGROUP_INFO items of childless qgroups never get updated in the quota tree, thus their numbers will stay the same in "btrfs qgroup show" output. [FIX] Just mark all qgroups dirty in qgroup_rescan_zero_tracking(), so even if we have childless qgroups, their QGROUP_INFO items will still get updated during rescan. Reported-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> Tested-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15Btrfs: clean up scrub is_dev_replace parameterOmar Sandoval1-14/+9
struct scrub_ctx has an ->is_dev_replace member, so there's no point in passing around is_dev_replace where sctx is available. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: add helper to obtain number of devices with ongoing dev-replaceAnand Jain1-14/+21
When the replace is running the fs_devices::num_devices also includes the replaced device, however in some operations like device delete and balance it needs the actual num_devices without the repalced devices. The function btrfs_num_devices() just provides that. And here is a scenario how balance and repalce items could co-exist: Consider balance is started and paused, now start the replace followed by a unmount or system power-cycle. During following mount, the open_ctree() first restarts the balance so it must check for the device replace otherwise our num_devices calculation will be wrong. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: add assertions where number of devices could go below 0Anand Jain1-2/+2
In preparation to add helper function to deduce the num_devices with replace running, use assert instead of BUG_ON or WARN_ON. The number of devices would not normally drop to 0 due to other checks so the assert is sufficient. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog, adjust the assert condition ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: remove unneeded NULL checks before kfreezhong jiang1-4/+2
Kfree has taken the NULL pointer into account. So remove the check before kfree. The issue is detected with the help of Coccinelle. Signed-off-by: zhong jiang <zhongjiang@huawei.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15Btrfs: do not unnecessarily pass write_lock_level when processing leafLiu Bo1-1/+1
As we're going to return right after the call, it's not necessary to get update the new write_lock_level from unlock_up. Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: Remove 'objectid' member from struct btrfs_rootMisono Tomohiro16-46/+50
There are two members in struct btrfs_root which indicate root's objectid: objectid and root_key.objectid. They are both set to the same value in __setup_root(): static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info, u64 objectid) { ... root->objectid = objectid; ... root->root_key.objectid = objecitd; ... } and not changed to other value after initialization. grep in btrfs directory shows both are used in many places: $ grep -rI "root->root_key.objectid" | wc -l 133 $ grep -rI "root->objectid" | wc -l 55 (4.17, inc. some noise) It is confusing to have two similar variable names and it seems that there is no rule about which should be used in a certain case. Since ->root_key itself is needed for tree reloc tree, let's remove 'objecitd' member and unify code to use ->root_key.objectid in all places. Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: remove a useless return statement in btrfs_block_rsv_addLu Fengqi1-3/+1
Since ret must be 0 here, don't have to return. No functional change and code readability is not hurt. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: Remove root parameter from btrfs_insert_dir_itemLu Fengqi5-14/+10
All callers pass the root tree of dir, we can push that down to the function itself. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: switch update_size to bool in btrfs_block_rsv_migrate and ↵Lu Fengqi6-17/+17
btrfs_rsv_add_bytes Using true and false here is closer to the expected semantic than using 0 and 1. No functional change. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: simplify the send_in_progress check in btrfs_delete_subvolumeLu Fengqi1-6/+5
Only when send_in_progress, we have to do something different such as btrfs_warn() and return -EPERM. Therefore, we could check send_in_progress first and process error handling, after the root_item_lock has been got. Just for better readability. No functional change. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-09-06Merge tag 'for-4.19-rc2-tag' of ↵Linus Torvalds9-55/+197
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: - fix for improper fsync after hardlink - fix for a corruption during file deduplication - use after free fixes - RCU warning fix - fix for buffered write to nodatacow file * tag 'for-4.19-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: Fix suspicious RCU usage warning in btrfs_debug_in_rcu btrfs: use after free in btrfs_quota_enable btrfs: btrfs_shrink_device should call commit transaction at the end btrfs: fix qgroup_free wrong num_bytes in btrfs_subvolume_reserve_metadata Btrfs: fix data corruption when deduplicating between different files Btrfs: sync log after logging new name Btrfs: fix unexpected failure of nocow buffered writes after snapshotting when low on space
2018-08-24btrfs: Fix suspicious RCU usage warning in btrfs_debug_in_rcuMisono Tomohiro1-2/+9
Commit 672d599041c8 ("btrfs: Use wrapper macro for rcu string to remove duplicate code") replaces some open coded RCU string handling with macro. It turns out that btrfs_debug_in_rcu() is used for the first time and the macro lacks lock/unlock of RCU string for non-debug case (i.e. when the message is not printed), leading to suspicious RCU usage warning when CONFIG_PROVE_RCU is on. Fix this by adding a wrapper to call lock/unlock for the non-debug case too. Fixes: 672d599041c8 ("btrfs: Use wrapper macro for rcu string to remove duplicate code") Reported-by: David Howells <dhowells@redhat.com> Tested-by: David Howells <dhowells@redhat.com> Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-23btrfs: use after free in btrfs_quota_enableDan Carpenter1-3/+2
The issue here is that btrfs_commit_transaction() frees "trans" on both the error and the success path. So the problem would be if btrfs_commit_transaction() succeeds, and then qgroup_rescan_init() fails. That means that "ret" is non-zero and "trans" is non-NULL and it leads to a use after free inside the btrfs_end_transaction() macro. Fixes: 340f1aa27f36 ("btrfs: qgroups: Move transaction management inside btrfs_quota_enable/disable") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-23btrfs: btrfs_shrink_device should call commit transaction at the endAnand Jain1-1/+6
Test case btrfs/164 reports use-after-free: [ 6712.084324] general protection fault: 0000 [#1] PREEMPT SMP .. [ 6712.195423] btrfs_update_commit_device_size+0x75/0xf0 [btrfs] [ 6712.201424] btrfs_commit_transaction+0x57d/0xa90 [btrfs] [ 6712.206999] btrfs_rm_device+0x627/0x850 [btrfs] [ 6712.211800] btrfs_ioctl+0x2b03/0x3120 [btrfs] Reason for this is that btrfs_shrink_device adds the resized device to the fs_devices::resized_devices after it has called the last commit transaction. So the list fs_devices::resized_devices is not empty when btrfs_shrink_device returns. Now the parent function btrfs_rm_device calls: btrfs_close_bdev(device); call_rcu(&device->rcu, free_device_rcu); and then does the transactio ncommit. It goes through the fs_devices::resized_devices in btrfs_update_commit_device_size and leads to use-after-free. Fix this by making sure btrfs_shrink_device calls the last needed btrfs_commit_transaction before the return. This is consistent with what the grow counterpart does and this makes sure the on-disk state is persistent when the function returns. Reported-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Tested-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-23btrfs: fix qgroup_free wrong num_bytes in btrfs_subvolume_reserve_metadataLu Fengqi1-9/+8
After btrfs_qgroup_reserve_meta_prealloc(), num_bytes will be assigned again by btrfs_calc_trans_metadata_size(). Once block_rsv fails, we can't properly free the num_bytes of the previous qgroup_reserve. Use a separate variable to store the num_bytes of the qgroup_reserve. Delete the comment for the qgroup_reserved that does not exist and add a comment about use_global_rsv. Fixes: c4c129db5da8 ("btrfs: drop unused parameter qgroup_reserved") CC: stable@vger.kernel.org # 4.18+ Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-23Btrfs: fix data corruption when deduplicating between different filesFilipe Manana1-0/+19
If we deduplicate extents between two different files we can end up corrupting data if the source range ends at the size of the source file, the source file's size is not aligned to the filesystem's block size and the destination range does not go past the size of the destination file size. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ xfs_io -f -c "pwrite -S 0x6b 0 2518890" /mnt/foo # The first byte with a value of 0xae starts at an offset (2518890) # which is not a multiple of the sector size. $ xfs_io -c "pwrite -S 0xae 2518890 102398" /mnt/foo # Confirm the file content is full of bytes with values 0x6b and 0xae. $ od -t x1 /mnt/foo 0000000 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b * 11467540 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b ae ae ae ae ae ae 11467560 ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae * 11777540 ae ae ae ae ae ae ae ae 11777550 # Create a second file with a length not aligned to the sector size, # whose bytes all have the value 0x6b, so that its extent(s) can be # deduplicated with the first file. $ xfs_io -f -c "pwrite -S 0x6b 0 557771" /mnt/bar # Now deduplicate the entire second file into a range of the first file # that also has all bytes with the value 0x6b. The destination range's # end offset must not be aligned to the sector size and must be less # then the offset of the first byte with the value 0xae (byte at offset # 2518890). $ xfs_io -c "dedupe /mnt/bar 0 1957888 557771" /mnt/foo # The bytes in the range starting at offset 2515659 (end of the # deduplication range) and ending at offset 2519040 (start offset # rounded up to the block size) must all have the value 0xae (and not # replaced with 0x00 values). In other words, we should have exactly # the same data we had before we asked for deduplication. $ od -t x1 /mnt/foo 0000000 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b * 11467540 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b ae ae ae ae ae ae 11467560 ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae * 11777540 ae ae ae ae ae ae ae ae 11777550 # Unmount the filesystem and mount it again. This guarantees any file # data in the page cache is dropped. $ umount /dev/sdb $ mount /dev/sdb /mnt $ od -t x1 /mnt/foo 0000000 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b * 11461300 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 00 11461320 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 11470000 ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae * 11777540 ae ae ae ae ae ae ae ae 11777550 # The bytes in range 2515659 to 2519040 have a value of 0x00 and not a # value of 0xae, data corruption happened due to the deduplication # operation. So fix this by rounding down, to the sector size, the length used for the deduplication when the following conditions are met: 1) Source file's range ends at its i_size; 2) Source file's i_size is not aligned to the sector size; 3) Destination range does not cross the i_size of the destination file. Fixes: e1d227a42ea2 ("btrfs: Handle unaligned length in extent_same") CC: stable@vger.kernel.org # 4.2+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-23Btrfs: sync log after logging new nameFilipe Manana3-19/+131
When we add a new name for an inode which was logged in the current transaction, we update the inode in the log so that its new name and ancestors are added to the log. However when we do this we do not persist the log, so the changes remain in memory only, and as a consequence, any ancestors that were created in the current transaction are updated such that future calls to btrfs_inode_in_log() return true. This leads to a subsequent fsync against such new ancestor directories returning immediately, without persisting the log, therefore after a power failure the new ancestor directories do not exist, despite fsync being called against them explicitly. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/A $ mkdir /mnt/B $ mkdir /mnt/A/C $ touch /mnt/B/foo $ xfs_io -c "fsync" /mnt/B/foo $ ln /mnt/B/foo /mnt/A/C/foo $ xfs_io -c "fsync" /mnt/A <power failure> After the power failure, directory "A" does not exist, despite the explicit fsync on it. Instead of fixing this by changing the behaviour of the explicit fsync on directory "A" to persist the log instead of doing nothing, make the logging of the new file name (which happens when creating a hard link or renaming) persist the log. This approach not only is simpler, not requiring addition of new fields to the inode in memory structure, but also gives us the same behaviour as ext4, xfs and f2fs (possibly other filesystems too). A test case for fstests follows soon. Fixes: 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes") Reported-by: Vijay Chidambaram <vvijay03@gmail.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-21Merge tag 'ovl-update-4.19' of ↵Linus Torvalds2-9/+7
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs updates from Miklos Szeredi: "This contains two new features: - Stack file operations: this allows removal of several hacks from the VFS, proper interaction of read-only open files with copy-up, possibility to implement fs modifying ioctls properly, and others. - Metadata only copy-up: when file is on lower layer and only metadata is modified (except size) then only copy up the metadata and continue to use the data from the lower file" * tag 'ovl-update-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (66 commits) ovl: Enable metadata only feature ovl: Do not do metacopy only for ioctl modifying file attr ovl: Do not do metadata only copy-up for truncate operation ovl: add helper to force data copy-up ovl: Check redirect on index as well ovl: Set redirect on upper inode when it is linked ovl: Set redirect on metacopy files upon rename ovl: Do not set dentry type ORIGIN for broken hardlinks ovl: Add an inode flag OVL_CONST_INO ovl: Treat metacopy dentries as type OVL_PATH_MERGE ovl: Check redirects for metacopy files ovl: Move some dir related ovl_lookup_single() code in else block ovl: Do not expose metacopy only dentry from d_real() ovl: Open file with data except for the case of fsync ovl: Add helper ovl_inode_realdata() ovl: Store lower data inode in ovl_inode ovl: Fix ovl_getattr() to get number of blocks from lower ovl: Add helper ovl_dentry_lowerdata() to get lower data dentry ovl: Copy up meta inode data from lowest data inode ovl: Modify ovl_lookup() and friends to lookup metacopy dentry ...
2018-08-17btrfs: readpages() should submit IO as read-aheadJens Axboe1-1/+1
a_ops->readpages() is only ever used for read-ahead. Ensure that we pass this information down to the block layer. Link: http://lkml.kernel.org/r/20180621010725.17813-4-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Chris Mason <clm@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17Btrfs: fix unexpected failure of nocow buffered writes after snapshotting ↵Robbie Ko4-21/+22
when low on space Commit e9894fd3e3b3 ("Btrfs: fix snapshot vs nocow writting") forced nocow writes to fallback to COW, during writeback, when a snapshot is created. This resulted in writes made before creating the snapshot to unexpectedly fail with ENOSPC during writeback when success (0) was returned to user space through the write system call. The steps leading to this problem are: 1. When it's not possible to allocate data space for a write, the buffered write path checks if a NOCOW write is possible. If it is, it will not reserve space and success (0) is returned to user space. 2. Then when a snapshot is created, the root's will_be_snapshotted atomic is incremented and writeback is triggered for all inode's that belong to the root being snapshotted. Incrementing that atomic forces all previous writes to fallback to COW during writeback (running delalloc). 3. This results in the writeback for the inodes to fail and therefore setting the ENOSPC error in their mappings, so that a subsequent fsync on them will report the error to user space. So it's not a completely silent data loss (since fsync will report ENOSPC) but it's a very unexpected and undesirable behaviour, because if a clean shutdown/unmount of the filesystem happens without previous calls to fsync, it is expected to have the data present in the files after mounting the filesystem again. So fix this by adding a new atomic named snapshot_force_cow to the root structure which prevents this behaviour and works the following way: 1. It is incremented when we start to create a snapshot after triggering writeback and before waiting for writeback to finish. 2. This new atomic is now what is used by writeback (running delalloc) to decide whether we need to fallback to COW or not. Because we incremented this new atomic after triggering writeback in the snapshot creation ioctl, we ensure that all buffered writes that happened before snapshot creation will succeed and not fallback to COW (which would make them fail with ENOSPC). 3. The existing atomic, will_be_snapshotted, is kept because it is used to force new buffered writes, that start after we started snapshotting, to reserve data space even when NOCOW is possible. This makes these writes fail early with ENOSPC when there's no available space to allocate, preventing the unexpected behaviour of writeback later failing with ENOSPC due to a fallback to COW mode. Fixes: e9894fd3e3b3 ("Btrfs: fix snapshot vs nocow writting") Signed-off-by: Robbie Ko <robbieko@synology.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-13Merge tag 'for-4.19-tag' of ↵Linus Torvalds46-2939/+1816
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs updates from David Sterba: "Mostly fixes and cleanups, nothing big, though the notable thing is the inserted/deleted lines delta -1124. User visible changes: - allow defrag on opened read-only files that have rw permissions; similar to what dedupe will allow on such files Core changes: - tree checker improvements, reported by fuzzing: * more checks for: block group items, essential trees * chunk type validation * mount time cross-checks that physical and logical chunks match * switch more error codes to EUCLEAN aka EFSCORRUPTED Fixes: - fsync corner case fixes - fix send failure when root has deleted files still open - send, fix incorrect file layout after hole punching beyond eof - fix races between mount and deice scan ioctl, found by fuzzing - fix deadlock when delayed iput is called from writeback on the same inode; rare but has been observed in practice, also removes code - fix pinned byte accounting, using the right percpu helpers; this should avoid some write IO inefficiency during low space conditions - don't remove block group that still has pinned bytes - reset on-disk device stats value after replace, otherwise this would report stale values for the new device Cleanups: - time64_t/timespec64 cleanups - remove remaining dead code in scrub handling NOCOW extents after disabling it in previous cycle - simplify fsync regarding ordered extents logic and remove all the related code - remove redundant arguments in order to reduce stack space consumption - remove support for V0 type of extents, not in use since 2.6.30 - remove several unused structure members - fewer indirect function calls by inlining some callbacks - qgroup rescan timing fixes - vfs: iget cleanups" * tag 'for-4.19-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (182 commits) btrfs: revert fs_devices state on error of btrfs_init_new_device btrfs: Exit gracefully when chunk map cannot be inserted to the tree btrfs: Introduce mount time chunk <-> dev extent mapping check btrfs: Verify that every chunk has corresponding block group at mount time btrfs: Check that each block group has corresponding chunk at mount time Btrfs: send, fix incorrect file layout after hole punching beyond eof btrfs: Use wrapper macro for rcu string to remove duplicate code btrfs: simplify btrfs_iget btrfs: lift make_bad_inode into btrfs_iget btrfs: simplify IS_ERR/PTR_ERR checks btrfs: btrfs_iget never returns an is_bad_inode inode btrfs: replace: Reset on-disk dev stats value after replace btrfs: extent-tree: Remove unused __btrfs_free_block_rsv btrfs: backref: Use ERR_CAST to return error code btrfs: Remove redundant btrfs_release_path from btrfs_unlink_subvol btrfs: Remove root parameter from btrfs_unlink_subvol btrfs: Remove fs_info from btrfs_add_root_ref btrfs: Remove fs_info from btrfs_del_root_ref btrfs: Remove fs_info from btrfs_del_root btrfs: Remove fs_info from btrfs_delete_delayed_dir_index ...
2018-08-13Merge branch 'work.mkdir' of ↵Linus Torvalds1-67/+39
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs icache updates from Al Viro: - NFS mkdir/open_by_handle race fix - analogous solution for FUSE, replacing the one currently in mainline - new primitive to be used when discarding halfway set up inodes on failed object creation; gives sane warranties re icache lookups not returning such doomed by still not freed inodes. A bunch of filesystems switched to that animal. - Miklos' fix for last cycle regression in iget5_locked(); -stable will need a slightly different variant, unfortunately. - misc bits and pieces around things icache-related (in adfs and jfs). * 'work.mkdir' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: jfs: don't bother with make_bad_inode() in ialloc() adfs: don't put inodes into icache new helper: inode_fake_hash() vfs: don't evict uninitialized inode jfs: switch to discard_new_inode() ext2: make sure that partially set up inodes won't be returned by ext2_iget() udf: switch to discard_new_inode() ufs: switch to discard_new_inode() btrfs: switch to discard_new_inode() new primitive: discard_new_inode() kill d_instantiate_no_diralias() nfs_instantiate(): prevent multiple aliases for directory inode
2018-08-06btrfs: revert fs_devices state on error of btrfs_init_new_deviceNaohiro Aota1-5/+24
When btrfs hits error after modifying fs_devices in btrfs_init_new_device() (such as btrfs_add_dev_item() returns error), it leaves everything as is, but frees allocated btrfs_device. As a result, fs_devices->devices and fs_devices->alloc_list contain already freed btrfs_device, leading to later use-after-free bug. Error path also messes the things like ->num_devices. While they go back to the original value by unscanning btrfs devices, it is safe to revert them here. Fixes: 79787eaab461 ("btrfs: replace many BUG_ONs with proper error handling") Signed-off-by: Naohiro Aota <naota@elisp.net> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: Exit gracefully when chunk map cannot be inserted to the treeQu Wenruo1-2/+6
It's entirely possible that a crafted btrfs image contains overlapping chunks. Although we can't detect such problem by tree-checker, it's not a catastrophic problem, current extent map can already detect such problem and return -EEXIST. We just only need to exit gracefully and fail the mount. Reported-by: Xu Wen <wen.xu@gatech.edu> Link: https://bugzilla.kernel.org/show_bug.cgi?id=200409 Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: Introduce mount time chunk <-> dev extent mapping checkQu Wenruo3-0/+193
This patch will introduce chunk <-> dev extent mapping check, to protect us against invalid dev extents or chunks. Since chunk mapping is the fundamental infrastructure of btrfs, extra check at mount time could prevent a lot of unexpected behavior (BUG_ON). Reported-by: Xu Wen <wen.xu@gatech.edu> Link: https://bugzilla.kernel.org/show_bug.cgi?id=200403 Link: https://bugzilla.kernel.org/show_bug.cgi?id=200407 Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: Verify that every chunk has corresponding block group at mount timeQu Wenruo1-1/+57
If a crafted image has missing block group items, it could cause unexpected behavior and breaks the assumption of 1:1 chunk<->block group mapping. Although we have the block group -> chunk mapping check, we still need chunk -> block group mapping check. This patch will do extra check to ensure each chunk has its corresponding block group. Link: https://bugzilla.kernel.org/show_bug.cgi?id=199847 Reported-by: Xu Wen <wen.xu@gatech.edu> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Gu Jinxiang <gujx@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: Check that each block group has corresponding chunk at mount timeQu Wenruo1-1/+27
A crafted btrfs image with incorrect chunk<->block group mapping will trigger a lot of unexpected things as the mapping is essential. Although the problem can be caught by block group item checker added in "btrfs: tree-checker: Verify block_group_item", it's still not sufficient. A sufficiently valid block group item can pass the check added by the mentioned patch but could fail to match the existing chunk. This patch will add extra block group -> chunk mapping check, to ensure we have a completely matching (start, len, flags) chunk for each block group at mount time. Here we reuse the original helper find_first_block_group(), which is already doing the basic bg -> chunk checks, adding further checks of the start/len and type flags. Link: https://bugzilla.kernel.org/show_bug.cgi?id=199837 Reported-by: Xu Wen <wen.xu@gatech.edu> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06Btrfs: send, fix incorrect file layout after hole punching beyond eofFilipe Manana1-0/+9
When doing an incremental send, if we have a file in the parent snapshot that has prealloc extents beyond EOF and in the send snapshot it got a hole punch that partially covers the prealloc extents, the send stream, when replayed by a receiver, can result in a file that has a size bigger than it should and filled with zeroes past the correct EOF. For example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ xfs_io -f -c "falloc -k 0 4M" /mnt/foobar $ xfs_io -c "pwrite -S 0xea 0 1M" /mnt/foobar $ btrfs subvolume snapshot -r /mnt /mnt/snap1 $ btrfs send -f /tmp/1.send /mnt/snap1 $ xfs_io -c "fpunch 1M 2M" /mnt/foobar $ btrfs subvolume snapshot -r /mnt /mnt/snap2 $ btrfs send -f /tmp/2.send -p /mnt/snap1 /mnt/snap2 $ stat --format %s /mnt/snap2/foobar 1048576 $ md5sum /mnt/snap2/foobar d31659e82e87798acd4669a1e0a19d4f /mnt/snap2/foobar $ umount /mnt $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt $ btrfs receive -f /mnt/1.snap /mnt $ btrfs receive -f /mnt/2.snap /mnt $ stat --format %s /mnt/snap2/foobar 3145728 # --> should be 1Mb and not 3Mb (which was the end offset of hole # punch operation) $ md5sum /mnt/snap2/foobar 117baf295297c2a995f92da725b0b651 /mnt/snap2/foobar # --> should be d31659e82e87798acd4669a1e0a19d4f as in the original fs This issue actually happens only since commit ffa7c4296e93 ("Btrfs: send, do not issue unnecessary truncate operations"), but before that commit we were issuing a write operation full of zeroes (to "punch" a hole) which was extending the file size beyond the correct value and then immediately issue a truncate operation to the correct size and undoing the previous write operation. Since the send protocol does not support fallocate, for extent preallocation and hole punching, fix this by not even attempting to send a "hole" (regular write full of zeroes) if it starts at an offset greater then or equals to the file's size. This approach, besides being much more simple then making send issue the truncate operation, adds the benefit of avoiding the useless pair of write of zeroes and truncate operations, saving time and IO at the receiver and reducing the size of the send stream. A test case for fstests follows soon. Fixes: ffa7c4296e93 ("Btrfs: send, do not issue unnecessary truncate operations") CC: stable@vger.kernel.org # 4.17+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: Use wrapper macro for rcu string to remove duplicate codeMisono Tomohiro4-31/+12
Cleanup patch and no functional changes. Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: simplify btrfs_igetAl Viro1-16/+13
Don't open-code iget_failed(), don't bother with btrfs_free_path(NULL), move handling of positive return values of btrfs_lookup_inode() from btrfs_read_locked_inode() to btrfs_iget() and kill now obviously pointless ASSERT() in there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: lift make_bad_inode into btrfs_igetAl Viro1-2/+2
We don't need to check is_bad_inode() after the call of btrfs_read_locked_inode() - it's exactly the same as checking return value for being non-zero. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: David Sterba <dsterba@suse.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: simplify IS_ERR/PTR_ERR checksAl Viro2-4/+3
IS_ERR(p) && PTR_ERR(p) == n is a weird way to spell p == ERR_PTR(n). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: David Sterba <dsterba@suse.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: btrfs_iget never returns an is_bad_inode inodeAl Viro3-14/+3
Just get rid of pointless checks. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>