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2018-05-28btrfs: drop lock parameter from update_ioctl_balance_args and renameDavid Sterba
The parameter controls locking of the stats part but we can lock it unconditionally, as this only happens once when balance starts. This is not performance critical. Add the prefix for an exported function. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: move and comment read-only check in btrfs_cancel_balanceDavid Sterba
Balance cannot be started on a read-only filesystem and will have to finish/exit before eg. going to read-only via remount. In case the filesystem is forcibly set to read-only after an error, balance will finish anyway and if the cancel call is too fast it will just wait for that to happen. The last case is when the balance is paused after mount but it's read-only and cancelling would want to delete the item. The test is moved after the check if balance is running at all, as it looks more logical to report "no balance running" instead of "read-only filesystem". Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: track running balance in a simpler wayDavid Sterba
Currently fs_info::balance_running is 0 or 1 and does not use the semantics of atomics. The pause and cancel check for 0, that can happen only after __btrfs_balance exits for whatever reason. Parallel calls to balance ioctl may enter btrfs_ioctl_balance multiple times but will block on the balance_mutex that protects the fs_info::flags bit. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: kill btrfs_fs_info::volume_mutexDavid Sterba
Mutual exclusion of device add/rm and balance was done by the volume mutex up to version 3.7. The commit 5ac00addc7ac091109 ("Btrfs: disallow mutually exclusive admin operations from user mode") added a bit that essentially tracked the same information. The status bit has an advantage over a mutex that it can be set without restrictions of function context, so it started to be used in the mount-time resuming of balance or device replace. But we don't really need to track the same information in two ways. 1) After the previous cleanups, the main ioctl handlers for add/del/resize copy the EXCL_OP bit next to the volume mutex, here it's clearly safe. 2) Resuming balance during mount or after rw remount will set only the EXCL_OP bit and the volume_mutex is held in the kernel thread that calls btrfs_balance. 3) Resuming device replace during mount or after rw remount is done after balance and is excluded by the EXCL_OP bit. It does not take the volume_mutex at all and completely relies on the EXCL_OP bit. 4) The resuming of balance and dev-replace cannot hapen at the same time as the ioctls cannot be started in parallel. Nevertheless, a crafted image could trigger that and a warning is printed. 5) Balance is normally excluded by EXCL_OP and also uses own mutex to protect against concurrent access to its status data. There's some trickery to maintain the right lock nesting in case we need to reexamine the status in btrfs_ioctl_balance. The volume_mutex is removed and the unlock/lock sequence is left in place as we might expect other waiters to proceed. 6) Similar to 5, the unlock/lock sequence is kept in btrfs_cancel_balance to allow waiters to continue. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: remove wrong use of volume_mutex from btrfs_dev_replace_startDavid Sterba
The volume mutex does not protect against anything in this case, the comment about scrub is right but not related to locking and looks confusing. The comment in btrfs_find_device_missing_or_by_path is wrong and confusing too. The device_list_mutex is not held here to protect device lookup, but in this case device replace cannot run in parallel with device removal (due to exclusive op protection), so we don't need further locking here. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: cleanup helpers that reset balance stateDavid Sterba
The function __cancel_balance name is confusing with the cancel operation of balance and it really resets the state of balance back to zero. The unset_balance_control helper is called only from one place and simple enough to be inlined. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: add sanity check when resuming balance after mountDavid Sterba
Replace a WARN_ON with a proper check and message in case something goes really wrong and resumed balance cannot set up its exclusive status. The check is a user friendly assertion, I don't expect to ever happen under normal circumstances. Also document that the paused balance starts here and owns the exclusive op status. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: add proper safety check before resuming dev-replaceDavid Sterba
The device replace is paused by unmount or read only remount, and resumed on next mount or write remount. The exclusive status should be checked properly as it's a global invariant and we must not allow 2 operations run. In this case, the balance can be also paused and resumed under same conditions. It's always checked first so dev-replace could see the EXCL_OP already taken, BUT, the ioctl would never let start both at the same time. Replace the WARN_ON with message and return 0, indicating no error as this is purely theoretical and the user will be informed. Resolving that manually should be possible by waiting for the other operation to finish or cancel the paused state. Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: move clearing of EXCL_OP out of __cancel_balanceDavid Sterba
Make the clearning visible in the callers so we can pair it with the test_and_set part. Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: move volume_mutex to callers of btrfs_rm_deviceDavid Sterba
Move locking and unlocking next to the BTRFS_FS_EXCL_OP bit manipulation so it's obvious that the two happen at the same time. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: move btrfs_init_dev_replace_tgtdev to dev-replace.c and make staticDavid Sterba
The function logically belongs there and there's only a single caller, no need to export it. No code changes. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: export and rename free_deviceDavid Sterba
The function will be used outside of volumes.c, the allocation btrfs_alloc_device is also exported. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: make success path out of btrfs_init_dev_replace_tgtdev more clearDavid Sterba
This is a preparatory cleanup that will make clear that the only successful way out of btrfs_init_dev_replace_tgtdev will also set the device_out to a valid pointer. With this guarantee, the callers can be simplified. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: squeeze btrfs_dev_replace_continue_on_mount to its callerDavid Sterba
The function is called once and is fairly small, we can merge it with the caller. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: cleanup btrfs_rm_device() promote fs_devices pointerAnand Jain
This function uses fs_info::fs_devices number of time, however we declare and use it only at the end, instead do it in the beginning of the function and use it. Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: cleanup find_device() drop list_head pointerAnand Jain
find_device() declares struct list_head *head pointer and used only once, instead just use it directly. Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: rename __btrfs_open_devices to open_fs_devicesAnand Jain
__btrfs_open_devices() is un-exported drop __ prefix and rename it to open_fs_devices(). Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: rename __btrfs_close_devices to close_fs_devicesAnand Jain
__btrfs_close_devices() is un-exported, drop the __ prefix and rename it to close_fs_devices(). Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: cleanup __btrfs_open_devices() drop head pointerAnand Jain
__btrfs_open_devices() declares struct list_head *head, however head is used only once, instead use btrfs_fs_devices::devices directly. Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: rename struct btrfs_fs_devices::listAnand Jain
btrfs_fs_devices::list is the list of BTRFS fsid in the kernel, a generic name 'list' makes it's search very difficult, rename it to fs_list. Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Drop fs_info parameter from btrfs_merge_delayed_refsNikolay Borisov
It's provided by the transaction handle. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Drop fs_info parameter from add_delayed_data_refNikolay Borisov
It's provided by the transaction handle. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Drop add_delayed_ref_head fs_info parameterNikolay Borisov
It's provided by the transaction handle. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Remove btrfs_wait_and_free_delalloc_workNikolay Borisov
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 Borisov
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 Borisov
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 Borisov
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: Remove map argument from try_release_extent_stateNikolay Borisov
It's not used in the function so just remove it. 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 Borisov
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 Tomohiro
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 Tomohiro
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>
2018-05-28btrfs: Move may_destroy_subvol() from ioctl.c to inode.cMisono Tomohiro
This is a preparation work to refactor btrfs_ioctl_snap_destroy() and to allow rmdir(2) to delete an empty subvolume. Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> [ minor update of the function comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: remove unused le_test_bit()Howard McLauchlan
With commit b18253ec57c0 ("btrfs: optimize free space tree bitmap conversion"), there are no more callers to le_test_bit(). This patch removes le_test_bit(). Signed-off-by: Howard McLauchlan <hmclauchlan@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: optimize free space tree bitmap conversionHoward McLauchlan
Presently, convert_free_space_to_extents() does a linear scan of the bitmap. We can speed this up with find_next_{bit,zero_bit}_le(). This patch replaces the linear scan with find_next_{bit,zero_bit}_le(). Testing shows a 20-33% decrease in execution time for convert_free_space_to_extents(). Since we change bitmap to be unsigned long, we have to do some casting for the bitmap cursor. In le_bitmap_set() it makes sense to use u8, as we are doing bit operations. Everywhere else, we're just using it for pointer arithmetic and not directly accessing it, so char seems more appropriate. Suggested-by: Omar Sandoval <osandov@osandov.com> Signed-off-by: Howard McLauchlan <hmclauchlan@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: clean up le_bitmap_{set, clear}()Howard McLauchlan
le_bitmap_set() is only used by free-space-tree, so move it there and make it static. le_bitmap_clear() is not used, so remove it. Signed-off-by: Howard McLauchlan <hmclauchlan@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: use fs_info for btrfs_handle_em_exist tracepointDavid Sterba
We really want to know to which filesystem the extent map events belong, but as it cannot be reached from the extent_map pointers, we need to pass it down the callchain. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: tests: pass fs_info to extent_map testsDavid Sterba
Preparatory work to pass fs_info to btrfs_add_extent_mapping so we can get a better tracepoint message. Extent maps do not need fs_info for anything so we only add a dummy one without any other initialization. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Consolidate error checking for btrfs_alloc_chunkNikolay Borisov
The second if is really a subcase of ret being less than 0. So introduce a generic if (ret < 0) check, and inside have another if which explicitly handles the -ENOSPC and any other errors. 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: Fix lock release orderNikolay Borisov
Locks should generally be released in the oppposite order they are acquired. Generally lock acquisiton ordering is used to ensure deadlocks don't happen. However, as becomes more complicated it's best to also maintain proper unlock order so as to avoid possible dead locks. This was found by code inspection and doesn't necessarily lead to a deadlock scenario. 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: Use while loop instead of labels in __endio_write_update_orderedNikolay Borisov
Currently __endio_write_update_ordered uses labels to implement what is essentially a simple while loop. This makes the code more cumbersome to follow than it actually has to be. No functional changes. No xfstest regressions were found during testing. 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: add comment about BTRFS_FS_EXCL_OPAnand Jain
Adds comments about BTRFS_FS_EXCL_OP to existing comments about the device locks. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> [ minor updates ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Drop delayed_refs argument from btrfs_check_delayed_seqNikolay Borisov
It's used to print its pointer in a debug statement but doesn't really bring any useful information to the error message. 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: rename btrfs_get_block_group_info and make it staticSu Yue
The function btrfs_get_block_group_info() was introduced by the commit 5af3e8cce8b7 ("Btrfs: make filesystem read-only when submitting barrier fails") which used it in disk-io.c. However, the function is only called in ioctl.c now. Its parameter type btrfs_ioctl_space_info* is only for ioctl. So, make it static and rename it to be original name get_block_group_info. No functional change. Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: Replace owner argument in add_pinned_bytes with a booleanNikolay Borisov
add_pinned_bytes really cares whether the bytes being pinned are either data or metadata. To that effect it checks whether the 'owner' argument is less than BTRFS_FIRST_FREE_OBJECTID (256). This works because owner can really have 2 types of values: a) For metadata extents it holds the level at which the parent is in the btree. This amounts to owner having the values 0-7 b) In case of modifying data extents, owner is the inode number to which those extents belongs. Let's make this more explicit byt converting the owner parameter to a boolean value and either pass it directly when we know the type of extents we are working with (i.e. in btrfs_free_tree_block). In cases when the parent function can be called on both metadata/data extents perform the check in the caller. This hopefully makes the interface of add_pinned_bytes more intuitive. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-24Merge tag 'for-4.17-rc6-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fix from David Sterba: "A one-liner that prevents leaking an internal error value 1 out of the ftruncate syscall. This has been observed in practice. The steps to reproduce make a common pattern (open/write/fync/ftruncate) but also need the application to not check only for negative values and happens only for compressed inlined files. The conditions are narrow but as this could break userspace I think it's better to merge it now and not wait for the merge window" * tag 'for-4.17-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: Btrfs: fix error handling in btrfs_truncate()
2018-05-24Btrfs: fix error handling in btrfs_truncate()Omar Sandoval
Jun Wu at Facebook reported that an internal service was seeing a return value of 1 from ftruncate() on Btrfs in some cases. This is coming from the NEED_TRUNCATE_BLOCK return value from btrfs_truncate_inode_items(). btrfs_truncate() uses two variables for error handling, ret and err. When btrfs_truncate_inode_items() returns non-zero, we set err to the return value. However, NEED_TRUNCATE_BLOCK is not an error. Make sure we only set err if ret is an error (i.e., negative). To reproduce the issue: mount a filesystem with -o compress-force=zstd and the following program will encounter return value of 1 from ftruncate: int main(void) { char buf[256] = { 0 }; int ret; int fd; fd = open("test", O_CREAT | O_WRONLY | O_TRUNC, 0666); if (fd == -1) { perror("open"); return EXIT_FAILURE; } if (write(fd, buf, sizeof(buf)) != sizeof(buf)) { perror("write"); close(fd); return EXIT_FAILURE; } if (fsync(fd) == -1) { perror("fsync"); close(fd); return EXIT_FAILURE; } ret = ftruncate(fd, 128); if (ret) { printf("ftruncate() returned %d\n", ret); close(fd); return EXIT_FAILURE; } close(fd); return EXIT_SUCCESS; } Fixes: ddfae63cc8e0 ("btrfs: move btrfs_truncate_block out of trans handle") CC: stable@vger.kernel.org # 4.15+ Reported-by: Jun Wu <quark@fb.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-21Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds
Pull vfs fixes from Al Viro: "Assorted fixes all over the place" * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: aio: fix io_destroy(2) vs. lookup_ioctx() race ext2: fix a block leak nfsd: vfs_mkdir() might succeed leaving dentry negative unhashed cachefiles: vfs_mkdir() might succeed leaving dentry negative unhashed unfuck sysfs_mount() kernfs: deal with kernfs_fill_super() failures cramfs: Fix IS_ENABLED typo befs_lookup(): use d_splice_alias() affs_lookup: switch to d_splice_alias() affs_lookup(): close a race with affs_remove_link() fix breakage caused by d_find_alias() semantics change fs: don't scan the inode cache before SB_BORN is set do d_instantiate/unlock_new_inode combinations safely iov_iter: fix memory leak in pipe_get_pages_alloc() iov_iter: fix return type of __pipe_get_pages()
2018-05-20Merge tag 'for-4.17-rc5-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "We've accumulated some fixes during the last week, some of them were in the works for a longer time but there are some newer ones too. Most of the fixes have a reproducer and fix user visible problems, also candidates for stable kernels. They IMHO qualify for a late rc, though I did not expect that many" * tag 'for-4.17-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix crash when trying to resume balance without the resume flag btrfs: Fix delalloc inodes invalidation during transaction abort btrfs: Split btrfs_del_delalloc_inode into 2 functions btrfs: fix reading stale metadata blocks after degraded raid1 mounts btrfs: property: Set incompat flag if lzo/zstd compression is set Btrfs: fix duplicate extents after fsync of file with prealloc extents Btrfs: fix xattr loss after power failure Btrfs: send, fix invalid access to commit roots due to concurrent snapshotting
2018-05-17btrfs: fix crash when trying to resume balance without the resume flagAnand Jain
We set the BTRFS_BALANCE_RESUME flag in the btrfs_recover_balance() only, which isn't called during the remount. So when resuming from the paused balance we hit the bug: kernel: kernel BUG at fs/btrfs/volumes.c:3890! :: kernel: balance_kthread+0x51/0x60 [btrfs] kernel: kthread+0x111/0x130 :: kernel: RIP: btrfs_balance+0x12e1/0x1570 [btrfs] RSP: ffffba7d0090bde8 Reproducer: On a mounted filesystem: btrfs balance start --full-balance /btrfs btrfs balance pause /btrfs mount -o remount,ro /dev/sdb /btrfs mount -o remount,rw /dev/sdb /btrfs To fix this set the BTRFS_BALANCE_RESUME flag in btrfs_resume_balance_async(). CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-17btrfs: Fix delalloc inodes invalidation during transaction abortNikolay Borisov
When a transaction is aborted btrfs_cleanup_transaction is called to cleanup all the various in-flight bits and pieces which migth be active. One of those is delalloc inodes - inodes which have dirty pages which haven't been persisted yet. Currently the process of freeing such delalloc inodes in exceptional circumstances such as transaction abort boiled down to calling btrfs_invalidate_inodes whose sole job is to invalidate the dentries for all inodes related to a root. This is in fact wrong and insufficient since such delalloc inodes will likely have pending pages or ordered-extents and will be linked to the sb->s_inode_list. This means that unmounting a btrfs instance with an aborted transaction could potentially lead inodes/their pages visible to the system long after their superblock has been freed. This in turn leads to a "use-after-free" situation once page shrink is triggered. This situation could be simulated by running generic/019 which would cause such inodes to be left hanging, followed by generic/176 which causes memory pressure and page eviction which lead to touching the freed super block instance. This situation is additionally detected by the unmount code of VFS with the following message: "VFS: Busy inodes after unmount of Self-destruct in 5 seconds. Have a nice day..." Additionally btrfs hits WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree)); in free_fs_root for the same reason. This patch aims to rectify the sitaution by doing the following: 1. Change btrfs_destroy_delalloc_inodes so that it calls invalidate_inode_pages2 for every inode on the delalloc list, this ensures that all the pages of the inode are released. This function boils down to calling btrfs_releasepage. During test I observed cases where inodes on the delalloc list were having an i_count of 0, so this necessitates using igrab to be sure we are working on a non-freed inode. 2. Since calling btrfs_releasepage might queue delayed iputs move the call out to btrfs_cleanup_transaction in btrfs_error_commit_super before calling run_delayed_iputs for the last time. This is necessary to ensure that delayed iputs are run. Note: this patch is tagged for 4.14 stable but the fix applies to older versions too but needs to be backported manually due to conflicts. CC: stable@vger.kernel.org # 4.14.x: 2b8773313494: btrfs: Split btrfs_del_delalloc_inode into 2 functions CC: stable@vger.kernel.org # 4.14.x Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add comment to igrab ] Signed-off-by: David Sterba <dsterba@suse.com>