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2018-11-21Btrfs: fix cur_offset in the error case for nocowRobbie Ko1-3/+2
commit 506481b20e818db40b6198815904ecd2d6daee64 upstream. When the cow_file_range fails, the related resources are unlocked according to the range [start..end), so the unlock cannot be repeated in run_delalloc_nocow. In some cases (e.g. cur_offset <= end && cow_start != -1), cur_offset is not updated correctly, so move the cur_offset update before cow_file_range. kernel BUG at mm/page-writeback.c:2663! Internal error: Oops - BUG: 0 [#1] SMP CPU: 3 PID: 31525 Comm: kworker/u8:7 Tainted: P O Hardware name: Realtek_RTD1296 (DT) Workqueue: writeback wb_workfn (flush-btrfs-1) task: ffffffc076db3380 ti: ffffffc02e9ac000 task.ti: ffffffc02e9ac000 PC is at clear_page_dirty_for_io+0x1bc/0x1e8 LR is at clear_page_dirty_for_io+0x14/0x1e8 pc : [<ffffffc00033c91c>] lr : [<ffffffc00033c774>] pstate: 40000145 sp : ffffffc02e9af4f0 Process kworker/u8:7 (pid: 31525, stack limit = 0xffffffc02e9ac020) Call trace: [<ffffffc00033c91c>] clear_page_dirty_for_io+0x1bc/0x1e8 [<ffffffbffc514674>] extent_clear_unlock_delalloc+0x1e4/0x210 [btrfs] [<ffffffbffc4fb168>] run_delalloc_nocow+0x3b8/0x948 [btrfs] [<ffffffbffc4fb948>] run_delalloc_range+0x250/0x3a8 [btrfs] [<ffffffbffc514c0c>] writepage_delalloc.isra.21+0xbc/0x1d8 [btrfs] [<ffffffbffc516048>] __extent_writepage+0xe8/0x248 [btrfs] [<ffffffbffc51630c>] extent_write_cache_pages.isra.17+0x164/0x378 [btrfs] [<ffffffbffc5185a8>] extent_writepages+0x48/0x68 [btrfs] [<ffffffbffc4f5828>] btrfs_writepages+0x20/0x30 [btrfs] [<ffffffc00033d758>] do_writepages+0x30/0x88 [<ffffffc0003ba0f4>] __writeback_single_inode+0x34/0x198 [<ffffffc0003ba6c4>] writeback_sb_inodes+0x184/0x3c0 [<ffffffc0003ba96c>] __writeback_inodes_wb+0x6c/0xc0 [<ffffffc0003bac20>] wb_writeback+0x1b8/0x1c0 [<ffffffc0003bb0f0>] wb_workfn+0x150/0x250 [<ffffffc0002b0014>] process_one_work+0x1dc/0x388 [<ffffffc0002b02f0>] worker_thread+0x130/0x500 [<ffffffc0002b6344>] kthread+0x10c/0x110 [<ffffffc000284590>] ret_from_fork+0x10/0x40 Code: d503201f a9025bb5 a90363b7 f90023b9 (d4210000) CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Robbie Ko <robbieko@synology.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-13Btrfs: fix use-after-free during inode evictionFilipe Manana1-1/+3
commit 421f0922a2cfb0c75acd9746454aaa576c711a65 upstream. At inode.c:evict_inode_truncate_pages(), when we iterate over the inode's extent states, we access an extent state record's "state" field after we unlocked the inode's io tree lock. This can lead to a use-after-free issue because after we unlock the io tree that extent state record might have been freed due to being merged into another adjacent extent state record (a previous inflight bio for a read operation finished in the meanwhile which unlocked a range in the io tree and cause a merge of extent state records, as explained in the comment before the while loop added in commit 6ca0709756710 ("Btrfs: fix hang during inode eviction due to concurrent readahead")). Fix this by keeping a copy of the extent state's flags in a local variable and using it after unlocking the io tree. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201189 Fixes: b9d0b38928e2 ("btrfs: Add handler for invalidate page") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-13btrfs: only free reserved extent if we didn't insert itJosef Bacik1-1/+9
commit 49940bdd57779c78462da7aa5a8650b2fea8c2ff upstream. When we insert the file extent once the ordered extent completes we free the reserved extent reservation as it'll have been migrated to the bytes_used counter. However if we error out after this step we'll still clear the reserved extent reservation, resulting in a negative accounting of the reserved bytes for the block group and space info. Fix this by only doing the free if we didn't successfully insert a file extent for this extent. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-13Btrfs: fix null pointer dereference on compressed write path errorFilipe Manana1-0/+1
commit 3527a018c00e5dbada2f9d7ed5576437b6dd5cfb upstream. At inode.c:compress_file_range(), under the "free_pages_out" label, we can end up dereferencing the "pages" pointer when it has a NULL value. This case happens when "start" has a value of 0 and we fail to allocate memory for the "pages" pointer. When that happens we jump to the "cont" label and then enter the "if (start == 0)" branch where we immediately call the cow_file_range_inline() function. If that function returns 0 (success creating an inline extent) or an error (like -ENOMEM for example) we jump to the "free_pages_out" label and then access "pages[i]" leading to a NULL pointer dereference, since "nr_pages" has a value greater than zero at that point. Fix this by setting "nr_pages" to 0 when we fail to allocate memory for the "pages" pointer. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201119 Fixes: 771ed689d2cd ("Btrfs: Optimize compressed writeback and reads") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-10Btrfs: fix unexpected failure of nocow buffered writes after snapshotting ↵Robbie Ko1-21/+4
when low on space [ Upstream commit 8ecebf4d767e2307a946c8905278d6358eda35c3 ] 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> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-05Btrfs: fix btrfs_write_inode vs delayed iput deadlockJosef Bacik1-26/+0
commit 3c4276936f6fbe52884b4ea4e6cc120b890a0f9f upstream. We recently ran into the following deadlock involving btrfs_write_inode(): [ +0.005066] __schedule+0x38e/0x8c0 [ +0.007144] schedule+0x36/0x80 [ +0.006447] bit_wait+0x11/0x60 [ +0.006446] __wait_on_bit+0xbe/0x110 [ +0.007487] ? bit_wait_io+0x60/0x60 [ +0.007319] __inode_wait_for_writeback+0x96/0xc0 [ +0.009568] ? autoremove_wake_function+0x40/0x40 [ +0.009565] inode_wait_for_writeback+0x21/0x30 [ +0.009224] evict+0xb0/0x190 [ +0.006099] iput+0x1a8/0x210 [ +0.006103] btrfs_run_delayed_iputs+0x73/0xc0 [ +0.009047] btrfs_commit_transaction+0x799/0x8c0 [ +0.009567] btrfs_write_inode+0x81/0xb0 [ +0.008008] __writeback_single_inode+0x267/0x320 [ +0.009569] writeback_sb_inodes+0x25b/0x4e0 [ +0.008702] wb_writeback+0x102/0x2d0 [ +0.007487] wb_workfn+0xa4/0x310 [ +0.006794] ? wb_workfn+0xa4/0x310 [ +0.007143] process_one_work+0x150/0x410 [ +0.008179] worker_thread+0x6d/0x520 [ +0.007490] kthread+0x12c/0x160 [ +0.006620] ? put_pwq_unlocked+0x80/0x80 [ +0.008185] ? kthread_park+0xa0/0xa0 [ +0.007484] ? do_syscall_64+0x53/0x150 [ +0.007837] ret_from_fork+0x29/0x40 Writeback calls: btrfs_write_inode btrfs_commit_transaction btrfs_run_delayed_iputs If iput() is called on that same inode, evict() will wait for writeback forever. btrfs_write_inode() was originally added way back in 4730a4bc5bf3 ("btrfs_dirty_inode") to support O_SYNC writes. However, ->write_inode() hasn't been used for O_SYNC since 148f948ba877 ("vfs: Introduce new helpers for syncing after writing to O_SYNC file or IS_SYNC inode"), so btrfs_write_inode() is actually unnecessary (and leads to a bunch of unnecessary commits). Get rid of it, which also gets rid of the deadlock. CC: stable@vger.kernel.org # 3.2+ Signed-off-by: Josef Bacik <jbacik@fb.com> [Omar: new commit message] Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-01Merge tag 'for-4.18-rc2-tag' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "We have a few regression fixes for qgroup rescan status tracking and the vm_fault_t conversion that mixed up the error values" * tag 'for-4.18-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: Btrfs: fix mount failure when qgroup rescan is in progress Btrfs: fix regression in btrfs_page_mkwrite() from vm_fault_t conversion btrfs: quota: Set rescan progress to (u64)-1 if we hit last leaf
2018-06-28Btrfs: fix regression in btrfs_page_mkwrite() from vm_fault_t conversionChris Mason1-1/+2
The vm_fault_t conversion commit introduced a ret2 variable for tracking the integer return values from internal btrfs functions. It was sometimes returning VM_FAULT_LOCKED for pages that were actually invalid and had been removed from the radix. Something like this: ret2 = btrfs_delalloc_reserve_space() // returns zero on success lock_page(page) if (page->mapping != inode->i_mapping) goto out_unlock; ... out_unlock: if (!ret2) { ... return VM_FAULT_LOCKED; } This ends up triggering this WARNING in btrfs_destroy_inode() WARN_ON(BTRFS_I(inode)->block_rsv.size); xfstests generic/095 was able to reliably reproduce the errors. Since out_unlock: is only used for errors, this fix moves it below the if (!ret2) check we use to return VM_FAULT_LOCKED for success. Fixes: a528a2415087 (btrfs: change return type of btrfs_page_mkwrite to vm_fault_t) Signed-off-by: Chris Mason <clm@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-06-26Merge tag 'for-4.18-rc1-tag' of ↵Linus Torvalds1-1/+3
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "Two regression fixes and an incorrect error value propagation fix from 'rename exchange'" * tag 'for-4.18-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: Btrfs: fix return value on rename exchange failure btrfs: fix invalid-free in btrfs_extent_same Btrfs: fix physical offset reported by fiemap for inline extents
2018-06-22Btrfs: fix return value on rename exchange failureFilipe Manana1-1/+3
If we failed during a rename exchange operation after starting/joining a transaction, we would end up replacing the return value, stored in the local 'ret' variable, with the return value from btrfs_end_transaction(). So this could end up returning 0 (success) to user space despite the operation having failed and aborted the transaction, because if there are multiple tasks having a reference on the transaction at the time btrfs_end_transaction() is called by the rename exchange, that function returns 0 (otherwise it returns -EIO and not the original error value). So fix this by not overwriting the return value on error after getting a transaction handle. Fixes: cdd1fedf8261 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT") CC: stable@vger.kernel.org # 4.9+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-06-15Merge tag 'vfs-timespec64' of ↵Linus Torvalds1-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground Pull inode timestamps conversion to timespec64 from Arnd Bergmann: "This is a late set of changes from Deepa Dinamani doing an automated treewide conversion of the inode and iattr structures from 'timespec' to 'timespec64', to push the conversion from the VFS layer into the individual file systems. As Deepa writes: 'The series aims to switch vfs timestamps to use struct timespec64. Currently vfs uses struct timespec, which is not y2038 safe. The series involves the following: 1. Add vfs helper functions for supporting struct timepec64 timestamps. 2. Cast prints of vfs timestamps to avoid warnings after the switch. 3. Simplify code using vfs timestamps so that the actual replacement becomes easy. 4. Convert vfs timestamps to use struct timespec64 using a script. This is a flag day patch. Next steps: 1. Convert APIs that can handle timespec64, instead of converting timestamps at the boundaries. 2. Update internal data structures to avoid timestamp conversions' Thomas Gleixner adds: 'I think there is no point to drag that out for the next merge window. The whole thing needs to be done in one go for the core changes which means that you're going to play that catchup game forever. Let's get over with it towards the end of the merge window'" * tag 'vfs-timespec64' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground: pstore: Remove bogus format string definition vfs: change inode times to use struct timespec64 pstore: Convert internal records to timespec64 udf: Simplify calls to udf_disk_stamp_to_time fs: nfs: get rid of memcpys for inode times ceph: make inode time prints to be long long lustre: Use long long type to print inode time fs: add timespec64_truncate()
2018-06-14Merge branch 'vfs_timespec64' of https://github.com/deepa-hub/vfs into ↵Arnd Bergmann1-4/+4
vfs-timespec64 Pull the timespec64 conversion from Deepa Dinamani: "The series aims to switch vfs timestamps to use struct timespec64. Currently vfs uses struct timespec, which is not y2038 safe. The flag patch applies cleanly. I've not seen the timestamps update logic change often. The series applies cleanly on 4.17-rc6 and linux-next tip (top commit: next-20180517). I'm not sure how to merge this kind of a series with a flag patch. We are targeting 4.18 for this. Let me know if you have other suggestions. The series involves the following: 1. Add vfs helper functions for supporting struct timepec64 timestamps. 2. Cast prints of vfs timestamps to avoid warnings after the switch. 3. Simplify code using vfs timestamps so that the actual replacement becomes easy. 4. Convert vfs timestamps to use struct timespec64 using a script. This is a flag day patch. I've tried to keep the conversions with the script simple, to aid in the reviews. I've kept all the internal filesystem data structures and function signatures the same. Next steps: 1. Convert APIs that can handle timespec64, instead of converting timestamps at the boundaries. 2. Update internal data structures to avoid timestamp conversions." I've pulled it into a branch based on top of the NFS changes that are now in mainline, so I could resolve the non-obvious conflict between the two while merging. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-06-07btrfs: change return type of btrfs_page_mkwrite to vm_fault_tSouptick Joarder1-14/+12
Use the new return type vm_fault_t for fault handler. For now, this is just documenting that the function returns a VM_FAULT value rather than an errno. Once all instances are converted, vm_fault_t will become a distinct type. Reference commit 1c8f422059ae ("mm: change return type to vm_fault_t") vmf_error() is the newly introduced inline function in 4.17-rc6. Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-06-06vfs: change inode times to use struct timespec64Deepa Dinamani1-4/+4
struct timespec is not y2038 safe. Transition vfs to use y2038 safe struct timespec64 instead. The change was made with the help of the following cocinelle script. This catches about 80% of the changes. All the header file and logic changes are included in the first 5 rules. The rest are trivial substitutions. I avoid changing any of the function signatures or any other filesystem specific data structures to keep the patch simple for review. The script can be a little shorter by combining different cases. But, this version was sufficient for my usecase. virtual patch @ depends on patch @ identifier now; @@ - struct timespec + struct timespec64 current_time ( ... ) { - struct timespec now = current_kernel_time(); + struct timespec64 now = current_kernel_time64(); ... - return timespec_trunc( + return timespec64_trunc( ... ); } @ depends on patch @ identifier xtime; @@ struct \( iattr \| inode \| kstat \) { ... - struct timespec xtime; + struct timespec64 xtime; ... } @ depends on patch @ identifier t; @@ struct inode_operations { ... int (*update_time) (..., - struct timespec t, + struct timespec64 t, ...); ... } @ depends on patch @ identifier t; identifier fn_update_time =~ "update_time$"; @@ fn_update_time (..., - struct timespec *t, + struct timespec64 *t, ...) { ... } @ depends on patch @ identifier t; @@ lease_get_mtime( ... , - struct timespec *t + struct timespec64 *t ) { ... } @te depends on patch forall@ identifier ts; local idexpression struct inode *inode_node; identifier i_xtime =~ "^i_[acm]time$"; identifier ia_xtime =~ "^ia_[acm]time$"; identifier fn_update_time =~ "update_time$"; identifier fn; expression e, E3; local idexpression struct inode *node1; local idexpression struct inode *node2; local idexpression struct iattr *attr1; local idexpression struct iattr *attr2; local idexpression struct iattr attr; identifier i_xtime1 =~ "^i_[acm]time$"; identifier i_xtime2 =~ "^i_[acm]time$"; identifier ia_xtime1 =~ "^ia_[acm]time$"; identifier ia_xtime2 =~ "^ia_[acm]time$"; @@ ( ( - struct timespec ts; + struct timespec64 ts; | - struct timespec ts = current_time(inode_node); + struct timespec64 ts = current_time(inode_node); ) <+... when != ts ( - timespec_equal(&inode_node->i_xtime, &ts) + timespec64_equal(&inode_node->i_xtime, &ts) | - timespec_equal(&ts, &inode_node->i_xtime) + timespec64_equal(&ts, &inode_node->i_xtime) | - timespec_compare(&inode_node->i_xtime, &ts) + timespec64_compare(&inode_node->i_xtime, &ts) | - timespec_compare(&ts, &inode_node->i_xtime) + timespec64_compare(&ts, &inode_node->i_xtime) | ts = current_time(e) | fn_update_time(..., &ts,...) | inode_node->i_xtime = ts | node1->i_xtime = ts | ts = inode_node->i_xtime | <+... attr1->ia_xtime ...+> = ts | ts = attr1->ia_xtime | ts.tv_sec | ts.tv_nsec | btrfs_set_stack_timespec_sec(..., ts.tv_sec) | btrfs_set_stack_timespec_nsec(..., ts.tv_nsec) | - ts = timespec64_to_timespec( + ts = ... -) | - ts = ktime_to_timespec( + ts = ktime_to_timespec64( ...) | - ts = E3 + ts = timespec_to_timespec64(E3) | - ktime_get_real_ts(&ts) + ktime_get_real_ts64(&ts) | fn(..., - ts + timespec64_to_timespec(ts) ,...) ) ...+> ( <... when != ts - return ts; + return timespec64_to_timespec(ts); ...> ) | - timespec_equal(&node1->i_xtime1, &node2->i_xtime2) + timespec64_equal(&node1->i_xtime2, &node2->i_xtime2) | - timespec_equal(&node1->i_xtime1, &attr2->ia_xtime2) + timespec64_equal(&node1->i_xtime2, &attr2->ia_xtime2) | - timespec_compare(&node1->i_xtime1, &node2->i_xtime2) + timespec64_compare(&node1->i_xtime1, &node2->i_xtime2) | node1->i_xtime1 = - timespec_trunc(attr1->ia_xtime1, + timespec64_trunc(attr1->ia_xtime1, ...) | - attr1->ia_xtime1 = timespec_trunc(attr2->ia_xtime2, + attr1->ia_xtime1 = timespec64_trunc(attr2->ia_xtime2, ...) | - ktime_get_real_ts(&attr1->ia_xtime1) + ktime_get_real_ts64(&attr1->ia_xtime1) | - ktime_get_real_ts(&attr.ia_xtime1) + ktime_get_real_ts64(&attr.ia_xtime1) ) @ depends on patch @ struct inode *node; struct iattr *attr; identifier fn; identifier i_xtime =~ "^i_[acm]time$"; identifier ia_xtime =~ "^ia_[acm]time$"; expression e; @@ ( - fn(node->i_xtime); + fn(timespec64_to_timespec(node->i_xtime)); | fn(..., - node->i_xtime); + timespec64_to_timespec(node->i_xtime)); | - e = fn(attr->ia_xtime); + e = fn(timespec64_to_timespec(attr->ia_xtime)); ) @ depends on patch forall @ struct inode *node; struct iattr *attr; identifier i_xtime =~ "^i_[acm]time$"; identifier ia_xtime =~ "^ia_[acm]time$"; identifier fn; @@ { + struct timespec ts; <+... ( + ts = timespec64_to_timespec(node->i_xtime); fn (..., - &node->i_xtime, + &ts, ...); | + ts = timespec64_to_timespec(attr->ia_xtime); fn (..., - &attr->ia_xtime, + &ts, ...); ) ...+> } @ depends on patch forall @ struct inode *node; struct iattr *attr; struct kstat *stat; identifier ia_xtime =~ "^ia_[acm]time$"; identifier i_xtime =~ "^i_[acm]time$"; identifier xtime =~ "^[acm]time$"; identifier fn, ret; @@ { + struct timespec ts; <+... ( + ts = timespec64_to_timespec(node->i_xtime); ret = fn (..., - &node->i_xtime, + &ts, ...); | + ts = timespec64_to_timespec(node->i_xtime); ret = fn (..., - &node->i_xtime); + &ts); | + ts = timespec64_to_timespec(attr->ia_xtime); ret = fn (..., - &attr->ia_xtime, + &ts, ...); | + ts = timespec64_to_timespec(attr->ia_xtime); ret = fn (..., - &attr->ia_xtime); + &ts); | + ts = timespec64_to_timespec(stat->xtime); ret = fn (..., - &stat->xtime); + &ts); ) ...+> } @ depends on patch @ struct inode *node; struct inode *node2; identifier i_xtime1 =~ "^i_[acm]time$"; identifier i_xtime2 =~ "^i_[acm]time$"; identifier i_xtime3 =~ "^i_[acm]time$"; struct iattr *attrp; struct iattr *attrp2; struct iattr attr ; identifier ia_xtime1 =~ "^ia_[acm]time$"; identifier ia_xtime2 =~ "^ia_[acm]time$"; struct kstat *stat; struct kstat stat1; struct timespec64 ts; identifier xtime =~ "^[acmb]time$"; expression e; @@ ( ( node->i_xtime2 \| attrp->ia_xtime2 \| attr.ia_xtime2 \) = node->i_xtime1 ; | node->i_xtime2 = \( node2->i_xtime1 \| timespec64_trunc(...) \); | node->i_xtime2 = node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \); | node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \); | stat->xtime = node2->i_xtime1; | stat1.xtime = node2->i_xtime1; | ( node->i_xtime2 \| attrp->ia_xtime2 \) = attrp->ia_xtime1 ; | ( attrp->ia_xtime1 \| attr.ia_xtime1 \) = attrp2->ia_xtime2; | - e = node->i_xtime1; + e = timespec64_to_timespec( node->i_xtime1 ); | - e = attrp->ia_xtime1; + e = timespec64_to_timespec( attrp->ia_xtime1 ); | node->i_xtime1 = current_time(...); | node->i_xtime2 = node->i_xtime1 = node->i_xtime3 = - e; + timespec_to_timespec64(e); | node->i_xtime1 = node->i_xtime3 = - e; + timespec_to_timespec64(e); | - node->i_xtime1 = e; + node->i_xtime1 = timespec_to_timespec64(e); ) Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Cc: <anton@tuxera.com> Cc: <balbi@kernel.org> Cc: <bfields@fieldses.org> Cc: <darrick.wong@oracle.com> Cc: <dhowells@redhat.com> Cc: <dsterba@suse.com> Cc: <dwmw2@infradead.org> Cc: <hch@lst.de> Cc: <hirofumi@mail.parknet.co.jp> Cc: <hubcap@omnibond.com> Cc: <jack@suse.com> Cc: <jaegeuk@kernel.org> Cc: <jaharkes@cs.cmu.edu> Cc: <jslaby@suse.com> Cc: <keescook@chromium.org> Cc: <mark@fasheh.com> Cc: <miklos@szeredi.hu> Cc: <nico@linaro.org> Cc: <reiserfs-devel@vger.kernel.org> Cc: <richard@nod.at> Cc: <sage@redhat.com> Cc: <sfrench@samba.org> Cc: <swhiteho@redhat.com> Cc: <tj@kernel.org> Cc: <trond.myklebust@primarydata.com> Cc: <tytso@mit.edu> Cc: <viro@zeniv.linux.org.uk>
2018-05-30Btrfs: clean up error handling in btrfs_truncate()Omar Sandoval1-19/+14
btrfs_truncate() uses two variables for error handling, ret and err (if this sounds familiar, it's because btrfs_truncate_inode_items() did something similar). This is error prone, as was made evident by "Btrfs: fix error handling in btrfs_truncate()". We only have err because we don't want to mask an error if we call btrfs_update_inode() and btrfs_end_transaction(), so let's make that its own scoped return variable and use ret everywhere else. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-30btrfs: Factor out write portion of btrfs_get_blocks_directNikolay Borisov1-99/+108
Now that the read side is extracted into its own function, do the same to the write side. This leaves btrfs_get_blocks_direct_write with the sole purpose of handling common locking required. Also flip the condition in btrfs_get_blocks_direct_write so that the write case comes first and we check for if (Create) rather than if (!create). This is purely subjective but I believe makes reading a bit more "linear". No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-30btrfs: Factor out read portion of btrfs_get_blocks_directNikolay Borisov1-13/+43
Currently this function handles both the READ and WRITE dio cases. This is facilitated by a bunch of 'if' statements, a goto short-circuit statement and a very perverse aliasing of "!created"(READ) case by setting lockstart = lockend and checking for lockstart < lockend for detecting the write. Let's simplify this mess by extracting the READ-only code into a separate __btrfs_get_block_direct_read function. This is only the first step, the next one will be to factor out the write side as well. The end goal will be to have the common locking/ unlocking code in btrfs_get_blocks_direct and then it will call either the read|write subvariants. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-30btrfs: return error value if create_io_em failed in cow_file_rangeSu Yue1-1/+3
In cow_file_range(), create_io_em() may fail, but its return value is not recorded. Then return value may be 0 even it failed which is a wrong behavior. Let cow_file_range() return PTR_ERR(em) if create_io_em() failed. Fixes: 6f9994dbabe5 ("Btrfs: create a helper to create em for IO") CC: stable@vger.kernel.org # 4.11+ Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-30btrfs: drop unused parameter qgroup_reservedGu JinXiang1-3/+1
Since commit 7775c8184ec0 ("btrfs: remove unused parameter from btrfs_subvolume_release_metadata") parameter qgroup_reserved is not used by caller of function btrfs_subvolume_reserve_metadata. So remove it. Signed-off-by: Gu JinXiang <gujx@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-30btrfs: balance dirty metadata pages in btrfs_finish_ordered_ioEthan Lien1-0/+3
[Problem description and how we fix it] We should balance dirty metadata pages at the end of btrfs_finish_ordered_io, since a small, unmergeable random write can potentially produce dirty metadata which is multiple times larger than the data itself. For example, a small, unmergeable 4KiB write may produce: 16KiB dirty leaf (and possibly 16KiB dirty node) in subvolume tree 16KiB dirty leaf (and possibly 16KiB dirty node) in checksum tree 16KiB dirty leaf (and possibly 16KiB dirty node) in extent tree Although we do call balance dirty pages in write side, but in the buffered write path, most metadata are dirtied only after we reach the dirty background limit (which by far only counts dirty data pages) and wakeup the flusher thread. If there are many small, unmergeable random writes spread in a large btree, we'll find a burst of dirty pages exceeds the dirty_bytes limit after we wakeup the flusher thread - which is not what we expect. In our machine, it caused out-of-memory problem since a page cannot be dropped if it is marked dirty. Someone may worry about we may sleep in btrfs_btree_balance_dirty_nodelay, but since we do btrfs_finish_ordered_io in a separate worker, it will not stop the flusher consuming dirty pages. Also, we use different worker for metadata writeback endio, sleep in btrfs_finish_ordered_io help us throttle the size of dirty metadata pages. [Reproduce steps] To reproduce the problem, we need to do 4KiB write randomly spread in a large btree. In our 2GiB RAM machine: 1) Create 4 subvolumes. 2) Run fio on each subvolume: [global] direct=0 rw=randwrite ioengine=libaio bs=4k iodepth=16 numjobs=1 group_reporting size=128G runtime=1800 norandommap time_based randrepeat=0 3) Take snapshot on each subvolume and repeat fio on existing files. 4) Repeat step (3) until we get large btrees. In our case, by observing btrfs_root_item->bytes_used, we have 2GiB of metadata in each subvolume tree and 12GiB of metadata in extent tree. 5) Stop all fio, take snapshot again, and wait until all delayed work is completed. 6) Start all fio. Few seconds later we hit OOM when the flusher starts to work. It can be reproduced even when using nocow write. Signed-off-by: Ethan Lien <ethanlien@synology.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-30btrfs: lift some btrfs_cross_ref_exist checks in nocow pathEthan Lien1-0/+15
In nocow path, we check if the extent is snapshotted in btrfs_cross_ref_exist(). We can do the similar check earlier and avoid unnecessary search into extent tree. A fio test on a Intel D-1531, 16GB RAM, SSD RAID-5 machine as follows: [global] group_reporting time_based thread=1 ioengine=libaio bs=4k iodepth=32 size=64G runtime=180 numjobs=8 rw=randwrite [file1] filename=/mnt/nocow/testfile IOPS result: unpatched patched 1 fio round: 46670 46958 snapshot 2 fio round: 51826 54498 3 fio round: 59767 61289 After snapshot, the first fio get about 5% performance gain. As we continually write to the same file, all writes will resume to nocow mode and eventually we have no performance gain. Signed-off-by: Ethan Lien <ethanlien@synology.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update comments ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-30btrfs: Remove fs_info argument from btrfs_uuid_tree_remLu Fengqi1-2/+2
This function always takes a transaction handle which contains a reference to the fs_info. Use that and remove the extra argument. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> [ rename the function ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28Btrfs: reserve space for O_TMPFILE orphan item deletionOmar Sandoval1-1/+2
btrfs_link() calls btrfs_orphan_del() if it's linking an O_TMPFILE but it doesn't reserve space to do so. Even before the removal of the orphan_block_rsv it wasn't using it. Fixes: ef3b9af50bfa ("Btrfs: implement inode_operations callback tmpfile") Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28Btrfs: get rid of unused orphan infrastructureOmar Sandoval1-42/+1
Now that we don't keep long-standing reservations for orphan items, root->orphan_block_rsv isn't used. We can git rid of it, along with: - root->orphan_lock, which was used to protect root->orphan_block_rsv - root->orphan_inodes, which was used as a refcount for root->orphan_block_rsv - BTRFS_INODE_ORPHAN_META_RESERVED, which was used to track reservations in root->orphan_block_rsv - btrfs_orphan_commit_root(), which was the last user of any of these and does nothing else Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28Btrfs: fix ENOSPC caused by orphan items reservationsOmar Sandoval1-120/+38
Currently, we keep space reserved for all inode orphan items until the inode is evicted (i.e., all references to it are dropped). We hit an issue where an application would keep a bunch of deleted files open (by design) and thus keep a large amount of space reserved, causing ENOSPC errors when other operations tried to reserve space. This long-standing reservation isn't absolutely necessary for a couple of reasons: - We can almost always make the reservation we need or steal from the global reserve for the orphan item - If we can't, it's not the end of the world if we drop the orphan item on the floor and let the next mount clean it up So, get rid of persistent reservation and just reserve space in btrfs_evict_inode(). Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28Btrfs: refactor btrfs_evict_inode() reserve refill danceOmar Sandoval1-71/+42
The truncate loop in btrfs_evict_inode() does two things at once: - It refills the temporary block reserve, potentially stealing from the global reserve or committing - It calls btrfs_truncate_inode_items() The tangle of continues hides the fact that these two steps are actually separate. Split the first step out into a separate function both for clarity and so that we can reuse it in a later patch. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28Btrfs: don't return ino to ino cache if inode item removal failsOmar Sandoval1-12/+13
In btrfs_evict_inode(), if btrfs_truncate_inode_items() fails, the inode item will still be in the tree but we still return the ino to the ino cache. That will blow up later when someone tries to allocate that ino, so don't return it to the cache. Fixes: 581bb050941b ("Btrfs: Cache free inode numbers in memory") Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28Btrfs: delete dead code in btrfs_orphan_commit_root()Omar Sandoval1-12/+0
btrfs_orphan_commit_root() tries to delete an orphan item for a subvolume in the tree root, but we don't actually insert that item in the first place. See commit 0a0d4415e338 ("Btrfs: delete dead code in btrfs_orphan_add()"). We can get rid of it. Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28Btrfs: get rid of BTRFS_INODE_HAS_ORPHAN_ITEMOmar Sandoval1-56/+20
Now that we don't add orphan items for truncate, there can't be races on adding or deleting an orphan item, so this bit is unnecessary. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28Btrfs: stop creating orphan items for truncateOmar Sandoval1-110/+49
Currently, we insert an orphan item during a truncate so that if there's a crash, we don't leak extents past the on-disk i_size. However, since commit 7f4f6e0a3f6d ("Btrfs: only update disk_i_size as we remove extents"), we keep disk_i_size in sync with the extent items as we truncate, so orphan cleanup will never have any extents to remove. Don't bother with the superfluous orphan item. Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28Btrfs: don't BUG_ON() in btrfs_truncate_inode_items()Omar Sandoval1-1/+4
btrfs_free_extent() can fail because of ENOMEM. There's no reason to panic here, we can just abort the transaction. Fixes: f4b9aa8d3b87 ("btrfs_truncate") Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28Btrfs: fix error handling in btrfs_truncate_inode_items()Omar Sandoval1-27/+28
btrfs_truncate_inode_items() uses two variables for error handling, ret and err. These are not handled consistently, leading to a couple of bugs. - Errors from btrfs_del_items() are handled but not propagated to the caller - If btrfs_run_delayed_refs() fails and aborts the transaction, we continue running Just use ret everywhere and simplify things a bit, fixing both of these issues. Fixes: 79787eaab461 ("btrfs: replace many BUG_ONs with proper error handling") Fixes: 1262133b8d6f ("Btrfs: account for crcs in delayed ref processing") Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28Btrfs: update stale comments referencing vmtruncate()Omar Sandoval1-3/+2
Commit a41ad394a03b ("Btrfs: convert to the new truncate sequence") changed btrfs_setsize() to call truncate_setsize() instead of vmtruncate() but didn't update the comment above it. truncate_setsize() never fails (the IS_SWAPFILE() check happens elsewhere), so remove the comment. Additionally, the comment above btrfs_page_mkwrite() references vmtruncate(), but truncate_setsize() does the size write and page locking now. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: rename btrfs_update_iflags to reflect which flags it touchesDavid Sterba1-2/+2
The btrfs inode flag flavour is now simply called 'inode flags' and the vfs inode are i_flags. Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Unexport and rename btrfs_invalidate_inodesNikolay Borisov1-64/+65
This function is no longer used outside of inode.c so just make it static. At the same time give a more becoming name, since it's not really invalidating the inodes but just calling d_prune_alias. Last, but not least - move the function above the sole caller to avoid introducing yet-another-pointless forward declaration. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: replace waitqueue_actvie with cond_wake_upDavid Sterba1-6/+3
Use the wrappers and reduce the amount of low-level details about the waitqueue management. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: take the last remnants of ->d_fsdata use outAl Viro1-6/+0
[spotted while going through ->d_fsdata handling around d_splice_alias(); don't really care which tree that goes through] The only thing even looking at ->d_fsdata in there (since 2012) had been kfree(dentry->d_fsdata) in btrfs_dentry_delete(). Which, incidentally, is all btrfs_dentry_delete() does. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Add assert in __btrfs_del_delalloc_inodeNikolay Borisov1-0/+1
The invariant is that when nr_delalloc_inodes is 0 then the root mustn't have any inodes on its delalloc inodes list. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Unexport btrfs_alloc_delalloc_workNikolay Borisov1-1/+8
It's used only in inode.c so makes no sense to have it exported. Also move the definition of btrfs_delalloc_work to inode.c since it's used only this file. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Remove delayed_iput member from btrfs_delalloc_workNikolay Borisov1-8/+3
When allocating a delalloc work we are always setting the delayed_iput to 0. So remove the delay_iput member of btrfs_delalloc_work, as a result also remove it as a parameter from btrfs_alloc_delalloc_work since it's not used anymore. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Remove delay_iput parameter from __start_delalloc_inodesNikolay Borisov1-9/+5
It's always set to 0 so remove it. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Qu Wenruo <wqu@suse.com> [ rename to start_delalloc_inodes ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Remove delayed_iput parameter from btrfs_start_delalloc_inodesNikolay Borisov1-2/+2
It's always set to 0, so just remove it and collapse the constant value to the only function we are passing it. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Remove delayed_iput parameter of btrfs_start_delalloc_rootsNikolay Borisov1-3/+2
This parameter was introduced alongside the function in eb73c1b7cea7 ("Btrfs: introduce per-subvolume delalloc inode list") to avoid deadlocks since this function was used in the transaction commit path. However, commit 8d875f95da43 ("btrfs: disable strict file flushes for renames and truncates") removed that usage, rendering the parameter obsolete. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Remove btrfs_wait_and_free_delalloc_workNikolay Borisov1-7/+2
This function is called from only 1 place and is effectively a wrapper over wait_completion/kfree. It doesn't really bring any value having those two calls in a separate function. Just open code it and remove it. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Remove tree argument from extent_writepagesNikolay Borisov1-4/+1
It can be directly referenced from the passed address_space so do that. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Use list_empty instead of list_empty_carefulNikolay Borisov1-2/+2
list_empty_careful usually is a signal of something tricky going on. Its usage in btrfs is actually not needed since both lists it's used on are local to a function and cannot be modified concurrently. So switch to plain list_empty. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Remove redundant tree argument from extent_readpagesNikolay Borisov1-3/+2
This function is called only from btrfs_readpage and is already passed the mapping. Simplify its signature by moving the code obtaining reference to the extent tree in the function. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Sink extent_tree arguments in try_release_extent_mappingNikolay Borisov1-7/+1
This function already gets the page from which the two extent trees are referenced. Simplify its signature by moving the code getting the trees inside the function. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Allow rmdir(2) to delete an empty subvolumeMisono Tomohiro1-1/+1
Change the behavior of rmdir(2) and allow it to delete an empty subvolume by using btrfs_delete_subvolume() which is used by btrfs_ioctl_snap_destroy(). This is a change in behaviour and has been requested by users. Deleting the subvolume by ioctl requires root permissions while the rmdir way does works with standard tools and syscalls for all users that can access the subvolume. The main usecase is to allow 'rm -rf /path/with/subvols' to simply work. We were not able to find any nasty usability surprises, the intention is to do the destructive rm. Without allowing rmdir, this would have to be followed by the ioctl subvolume deletion, which is more of an annoyance. Implementation details: The required lock for @dir and inode of @dentry is already acquired in vfs layer. We need some check before deleting a subvolume. Permission check is done in vfs layer, emptiness check is in btrfs_rmdir() and additional check (i.e. neither the subvolume is a default subvolume nor send is in progress) is in btrfs_delete_subvolume(). Note that in btrfs_ioctl_snap_destroy(), d_delete() is called after btrfs_delete_subvolume(). For rmdir(2), d_delete() is called in vfs layer later. Tested-by: Goffredo Baroncelli <kreijack@inwind.it> Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> [ enhance changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Factor out the main deletion process from btrfs_ioctl_snap_destroy()Misono Tomohiro1-2/+141
Factor out the second half of btrfs_ioctl_snap_destroy() as btrfs_delete_subvolume(), which performs some subvolume specific checks before deletion: 1. send is not in progress 2. the subvolume is not the default subvolume 3. the subvolume does not contain other subvolumes and actual deletion process. btrfs_delete_subvolume() requires inode_lock for both @dir and inode of @dentry. The remaining part of btrfs_ioctl_snap_destroy() is mainly permission checks. Note that call of d_delete() is not included in btrfs_delete_subvolume() as this function will also be used by btrfs_rmdir() to delete an empty subvolume and in that case d_delete() is called in VFS layer. As a result, btrfs_unlink_subvol() and may_destroy_subvol() become static functions. No functional changes. Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> [ minor comment updates ] Signed-off-by: David Sterba <dsterba@suse.com>
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