- 17 Dec, 2018 40 commits
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Lu Fengqi authored
The test case btrfs/001 with inode_cache mount option will encounter the following warning: WARNING: CPU: 1 PID: 23700 at fs/btrfs/inode.c:956 cow_file_range.isra.19+0x32b/0x430 [btrfs] CPU: 1 PID: 23700 Comm: btrfs Kdump: loaded Tainted: G W O 4.20.0-rc4-custom+ #30 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:cow_file_range.isra.19+0x32b/0x430 [btrfs] Call Trace: ? free_extent_buffer+0x46/0x90 [btrfs] run_delalloc_nocow+0x455/0x900 [btrfs] btrfs_run_delalloc_range+0x1a7/0x360 [btrfs] writepage_delalloc+0xf9/0x150 [btrfs] __extent_writepage+0x125/0x3e0 [btrfs] extent_write_cache_pages+0x1b6/0x3e0 [btrfs] ? __wake_up_common_lock+0x63/0xc0 extent_writepages+0x50/0x80 [btrfs] do_writepages+0x41/0xd0 ? __filemap_fdatawrite_range+0x9e/0xf0 __filemap_fdatawrite_range+0xbe/0xf0 btrfs_fdatawrite_range+0x1b/0x50 [btrfs] __btrfs_write_out_cache+0x42c/0x480 [btrfs] btrfs_write_out_ino_cache+0x84/0xd0 [btrfs] btrfs_save_ino_cache+0x551/0x660 [btrfs] commit_fs_roots+0xc5/0x190 [btrfs] btrfs_commit_transaction+0x2bf/0x8d0 [btrfs] btrfs_mksubvol+0x48d/0x4d0 [btrfs] btrfs_ioctl_snap_create_transid+0x170/0x180 [btrfs] btrfs_ioctl_snap_create_v2+0x124/0x180 [btrfs] btrfs_ioctl+0x123f/0x3030 [btrfs] The file extent generation of the free space inode is equal to the last snapshot of the file root, so the inode will be passed to cow_file_rage. But the inode was created and its extents were preallocated in btrfs_save_ino_cache, there are no cow copies on disk. The preallocated extent is not yet in the extent tree, and btrfs_cross_ref_exist will ignore the -ENOENT returned by check_committed_ref, so we can directly write the inode to the disk. Fixes: 78d4295b ("btrfs: lift some btrfs_cross_ref_exist checks in nocow path") CC: stable@vger.kernel.org # 4.18+ Reviewed-by:
Filipe Manana <fdmanana@suse.com> Signed-off-by:
Lu Fengqi <lufq.fnst@cn.fujitsu.com> Signed-off-by:
David Sterba <dsterba@suse.com>
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Filipe Manana authored
The log tree has a long standing problem that when a file is fsync'ed we only check for new ancestors, created in the current transaction, by following only the hard link for which the fsync was issued. We follow the ancestors using the VFS' dget_parent() API. This means that if we create a new link for a file in a directory that is new (or in an any other new ancestor directory) and then fsync the file using an old hard link, we end up not logging the new ancestor, and on log replay that new hard link and ancestor do not exist. In some cases, involving renames, the file will not exist at all. Example: mkfs.btrfs -f /dev/sdb mount /dev/sdb /mnt mkdir /mnt/A touch /mnt/foo ln /mnt/foo /mnt/A/bar xfs_io -c fsync /mnt/foo <power failure> In this example after log replay only the hard link named 'foo' exists and directory A does not exist, which is unexpected. In other major linux filesystems, such as ext4, xfs and f2fs for example, both hard links exist and so does directory A after mounting again the filesystem. Checking if any new ancestors are new and need to be logged was added in 2009 by commit 12fcfd22 ("Btrfs: tree logging unlink/rename fixes"), however only for the ancestors of the hard link (dentry) for which the fsync was issued, instead of checking for all ancestors for all of the inode's hard links. So fix this by tracking the id of the last transaction where a hard link was created for an inode and then on fsync fallback to a full transaction commit when an inode has more than one hard link and at least one new hard link was created in the current transaction. This is the simplest solution since this is not a common use case (adding frequently hard links for which there's an ancestor created in the current transaction and then fsync the file). In case it ever becomes a common use case, a solution that consists of iterating the fs/subvol btree for each hard link and check if any ancestor is new, could be implemented. This solves many unexpected scenarios reported by Jayashree Mohan and Vijay Chidambaram, and for which there is a new test case for fstests under review. Fixes: 12fcfd22 ("Btrfs: tree logging unlink/rename fixes") CC: stable@vger.kernel.org # 4.4+ Reported-by:
Vijay Chidambaram <vvijay03@gmail.com> Reported-by:
Jayashree Mohan <jayashree2912@gmail.com> Signed-off-by:
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David Sterba authored
The first auto-assigned value to enum is 0, we can use that and not initialize all members where the auto-increment does the same. This is used for values that are not part of on-disk format. Reviewed-by:
Omar Sandoval <osandov@fb.com> Reviewed-by:
Qu Wenruo <wqu@suse.com> Reviewed-by:
Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: ordered extent flags. Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: extent map flags. Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: extent buffer flags; Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: root tree flags. Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: internal filesystem states. Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: block reserve types. Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: global filesystem states. Reviewed-by:
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Nikolay Borisov authored
This function really checks whether adding more data to the bio will straddle a stripe/chunk. So first let's give it a more appropraite name - btrfs_bio_fits_in_stripe. Secondly, the offset parameter was never used to just remove it. Thirdly, pages are submitted to either btree or data inodes so it's guaranteed that tree->ops is set so replace the check with an ASSERT. Finally, document the parameters of the function. No functional changes. Signed-off-by:
Nikolay Borisov <nborisov@suse.com> Reviewed-by:
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Lu Fengqi authored
When it was introduced in commit f094ac32 ("Btrfs: fix NULL pointer after aborting a transaction"), it was not used. Signed-off-by:
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Johannes Thumshirn authored
Document why map_private_extent_buffer() cannot return '1' (i.e. the map spans two pages) for the csum_tree_block() case. The current algorithm for detecting a page boundary crossing in map_private_extent_buffer() will return a '1' *IFF* the extent buffer's offset in the page + the offset passed in by csum_tree_block() and the minimal length passed in by csum_tree_block() - 1 are bigger than PAGE_SIZE. We always pass BTRFS_CSUM_SIZE (32) as offset and a minimal length of 32 and the current extent buffer allocator always guarantees page aligned extends, so the above condition can't be true. Reviewed-by:
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Johannes Thumshirn authored
In map_private_extent_buffer() the 'offset' variable is initialized to a page aligned version of the 'start' parameter. But later on it is overwritten with either the offset from the extent buffer's start or 0. So get rid of the initial initialization. Reviewed-by:
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Filipe Manana authored
When a transaction commit starts, it attempts to pause scrub and it blocks until the scrub is paused. So while the transaction is blocked waiting for scrub to pause, we can not do memory allocation with GFP_KERNEL from scrub, otherwise we risk getting into a deadlock with reclaim. Checking for scrub pause requests is done early at the beginning of the while loop of scrub_stripe() and later in the loop, scrub_extent() and scrub_raid56_parity() are called, which in turn call scrub_pages() and scrub_pages_for_parity() respectively. These last two functions do memory allocations using GFP_KERNEL. Same problem could happen while scrubbing the super blocks, since it calls scrub_pages(). We also can not have any of the worker tasks, created by the scrub task, doing GFP_KERNEL allocations, because before pausing, the scrub task waits for all the worker tasks to complete (also done at scrub_stripe()). So make sure GFP_NOFS is used for the memory allocations because at any time a scrub pause request can happen from another task that started to commit a transaction. Fixes: 58c4e173 ("btrfs: scrub: use GFP_KERNEL on the submission path") CC: stable@vger.kernel.org # 4.6+ Reviewed-by:
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Nikolay Borisov authored
For data inodes this hook does nothing but to return -EAGAIN which is used to signal to the endio routines that this bio belongs to a data inode. If this is the case the actual retrying is handled by bio_readpage_error. Alternatively, if this bio belongs to the btree inode then btree_io_failed_hook just does some cleanup and doesn't retry anything. This patch simplifies the code flow by eliminating readpage_io_failed_hook and instead open-coding btree_io_failed_hook in end_bio_extent_readpage. Also eliminate some needless checks since IO is always performed on either data inode or btree inode, both of which are guaranteed to have their extent_io_tree::ops set. Signed-off-by:
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Johannes Thumshirn authored
The btrfs_bio_end_io_t typedef was introduced with commit a1d3c478 ("btrfs: btrfs_multi_bio replaced with btrfs_bio") but never used anywhere. This commit also introduced a forward declaration of 'struct btrfs_bio' which is only needed for btrfs_bio_end_io_t. Remove both as they're not needed anywhere. Reviewed-by:
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David Sterba authored
The end_io callback implemented as btrfs_io_bio_endio_readpage only calls kfree. Also the callback is set only in case the csum buffer is allocated and not pointing to the inline buffer. We can use that information to drop the indirection and call a helper that will free the csums only in the right case. This shrinks struct btrfs_io_bio by 8 bytes. Reviewed-by:
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David Sterba authored
The io_bio tracks checksums and has an inline buffer or an allocated one. And there's a third member that points to the right one, but we don't need to use an extra pointer for that. Let btrfs_io_bio::csum point to the right buffer and check that the inline buffer is not accidentally freed. This shrinks struct btrfs_io_bio by 8 bytes. Reviewed-by:
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David Sterba authored
The async_cow::root is used to propagate fs_info to async_cow_submit. We can't use inode to reach it because it could become NULL after write without compression in async_cow_start. Reviewed-by:
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David Sterba authored
There's one caller and its code is simple, we can open code it in run_one_async_done. The errors are passed through bio. Reviewed-by:
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Anand Jain authored
Print a kernel log message when the balance ends, either for cancel or completed or if it is paused. Signed-off-by:
Anand Jain <anand.jain@oracle.com> Reviewed-by:
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Anand Jain authored
The information about balance arguments is important for system audit, this patch prints the textual representation when balance starts or is resumed. Example command: $ btrfs balance start -f -mprofiles=raid1,convert=single,soft -dlimit=10..20,usage=50 /btrfs Example kernel log output: BTRFS info (device sdb): balance: start -f -dusage=50,limit=10..20 -mconvert=single,soft,profiles=raid1 -sconvert=single,soft,profiles=raid1 Signed-off-by:
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Anand Jain authored
Factor out helper that describes block group flags from describe_relocation. The result will not be longer than the given size. Signed-off-by:
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Filipe Manana authored
If the quota enable and snapshot creation ioctls are called concurrently we can get into a deadlock where the task enabling quotas will deadlock on the fs_info->qgroup_ioctl_lock mutex because it attempts to lock it twice, or the task creating a snapshot tries to commit the transaction while the task enabling quota waits for the former task to commit the transaction while holding the mutex. The following time diagrams show how both cases happen. First scenario: CPU 0 CPU 1 btrfs_ioctl() btrfs_ioctl_quota_ctl() btrfs_quota_enable() mutex_lock(fs_info->qgroup_ioctl_lock) btrfs_start_transaction() btrfs_ioctl() btrfs_ioctl_snap_create_v2 create_snapshot() --> adds snapshot to the list pending_snapshots of the current transaction btrfs_commit_transaction() create_pending_snapshots() create_pending_snapshot() qgroup_account_snapshot() btrfs_qgroup_inherit() mutex_lock(fs_info->qgroup_ioctl_lock) --> deadlock, mutex already locked by this task at btrfs_quota_enable() Second scenario: CPU 0 CPU 1 btrfs_ioctl() btrfs_ioctl_quota_ctl() btrfs_quota_enable() mutex_lock(fs_info->qgroup_ioctl_lock) btrfs_start_transaction() btrfs_ioctl() btrfs_ioctl_snap_create_v2 create_snapshot() --> adds snapshot to the list pending_snapshots of the current transaction btrfs_commit_transaction() --> waits for task at CPU 0 to release its transaction handle btrfs_commit_transaction() --> sees another task started the transaction commit first --> releases its transaction handle --> waits for the transaction commit to be completed by the task at CPU 1 create_pending_snapshot() qgroup_account_snapshot() btrfs_qgroup_inherit() mutex_lock(fs_info->qgroup_ioctl_lock) --> deadlock, task at CPU 0 has the mutex locked but it is waiting for us to finish the transaction commit So fix this by setting the quota enabled flag in fs_info after committing the transaction at btrfs_quota_enable(). This ends up serializing quota enable and snapshot creation as if the snapshot creation happened just before the quota enable request. The quota rescan task, scheduled after committing the transaction in btrfs_quote_enable(), will do the accounting. Fixes: 6426c7ad ("btrfs: qgroup: Fix qgroup accounting when creating snapshot") Signed-off-by: -
Filipe Manana authored
The available allocation bits members from struct btrfs_fs_info are protected by a sequence lock, and when starting balance we access them incorrectly in two different ways: 1) In the read sequence lock loop at btrfs_balance() we use the values we read from fs_info->avail_*_alloc_bits and we can immediately do actions that have side effects and can not be undone (printing a message and jumping to a label). This is wrong because a retry might be needed, so our actions must not have side effects and must be repeatable as long as read_seqretry() returns a non-zero value. In other words, we were essentially ignoring the sequence lock; 2) Right below the read sequence lock loop, we were reading the values from avail_metadata_alloc_bits and avail_data_alloc_bits without any protection from concurrent writers, that is, reading them outside of the read sequence lock critical section. So fix this by making sure we only read the available allocation bits while in a read sequence lock critical section and that what we do in the critical section is repeatable (has nothing that can not be undone) so that any eventual retry that is needed is handled properly. Fixes: de98ced9 ("Btrfs: use seqlock to protect fs_info->avail_{data, metadata, system}_alloc_bits") Fixes: 14506127 ("btrfs: fix a bogus warning when converting only data or metadata") Reviewed-by:
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Filipe Manana authored
We can have a lot freed extents during the life span of transaction, so the red black tree that keeps track of the ranges of each freed extent (fs_info->freed_extents[]) can get quite big. When finishing a transaction commit we find each range, process it (discard the extents, unpin them) and then remove it from the red black tree. We can use an extent state record as a cache when searching for a range, so that when we clean the range we can use the cached extent state we passed to the search function instead of iterating the red black tree again. Doing things as fast as possible when finishing a transaction (in state TRANS_STATE_UNBLOCKED) is convenient as it reduces the time we block another task that wants to commit the next transaction. So change clear_extent_dirty() to allow an optional extent state record to be passed as an argument, which will be passed down to __clear_extent_bit. Reviewed-by:
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Nikolay Borisov authored
This patch lands the last case which needs to be handled by the fsid change code. Namely, this is the case where a multidisk filesystem has already undergone at least one successful fsid change i.e all disks have the METADATA_UUID incompat bit and power failure occurs as another fsid change is in progress. When such an event occurs, disks could be split in 2 groups. One of the groups will have both METADATA_UUID and CHANGING_FSID_V2 flags set coupled with old fsid/metadata_uuid pairs. The other group of disks will have only METADATA_UUID bit set and their fsid will be different than the one in disks in the first group. Here we look at the following cases: a) A disk from the first group is scanned first, so fs_devices is created with stale fsid/metdata_uuid. Then when a disk from the second group is scanned it needs to first check whether there exists such an fs_devices that has fsid_change set to true (because it was created with a disk having the CHANGING_FSID_V2 flag), the metadata_uuid and fsid of the fs_devices will be different (since it was created by a disk which already has had at least 1 successful fsid change) and finally the metadata_uuid of the fs_devices will equal that of the currently scanned disk (because metadata_uuid never really changes). When the correct fs_devices is found the information from the scanned disk will replace the current one in fs_devices since the scanned disk will have higher generation number. b) A disk from the second group is scanned so fs_devices is created as usual with differing fsid/metdata_uid. Then when a disk from the first group is scanned the code detects that it has both CHANGING_FSID_V2 and METADATA_UUID flags set and will search for fs_devices that has differing metadata_uuid/fsid and whose metadata_uuid is the same as that of the scanned device. Signed-off-by:
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Nikolay Borisov authored
This commit continues hardening the scanning code to handle cases where power loss could have caused disks in a multi-disk filesystem to be in inconsistent state. Namely handle the situation that can occur when some of the disks in multi-disk fs have completed their fsid change i.e they have METADATA_UUID incompat flag set, have cleared the CHANGING_FSID_V2 flag and their fsid/metadata_uuid are different. At the same time the other half of the disks will have their fsid/metadata_uuid unchanged and will only have CHANGING_FSID_V2 flag. This is handled by introducing code in the scan path which: a) Handles the case when a device with CHANGING_FSID_V2 flag is scanned and as a result btrfs_fs_devices is created with matching fsid/metdata_uuid. Subsequently, when a device with completed fsid change is scanned it will detect this via the new code in find_fsid i.e that such an fs_devices exist that fsid_change flag is set to true, it's metadata_uuid/fsid match and the metadata_uuid of the scanned device matches that of the fs_devices. In this case, it's important to note that the devices which has its fsid change completed will have a higher generation number than the device with FSID_CHANGING_V2 flag set, so its superblock block will be used during mount. To prevent an assertion triggering because the sb used for mounting will have differing fsid/metadata_uuid than the ones in the fs_devices struct also add code in device_list_add which overwrites the values in fs_devices. b) Alternatively we can end up with a device that completed its fsid change be scanned first which will create the respective btrfs_fs_devices struct with differing fsid/metadata_uuid. In this case when a device with FSID_CHANGING_V2 flag set is scanned it will call the newly added find_fsid_inprogress function which will return the correct fs_devices. Signed-off-by:
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Nikolay Borisov authored
In order to gracefully handle split-brain scenario during fsid change (which are very unlikely, yet possible), two more pieces of information will be necessary: 1. The highest generation number among all devices registered to a particular btrfs_fs_devices 2. A boolean flag whether a given btrfs_fs_devices was created by a device which had the FSID_CHANGING_V2 flag set. This is a preparatory patch and just introduces the variables as well as code which sets them, their actual use is going to happen in a later patch. Signed-off-by:
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Nikolay Borisov authored
Even though fsid change without rewrite is a very quick operation it's still possible to experience a split-brain scenario if power loss occurs at the most inconvenient time. This patch handles the case where power failure occurs while the first transaction (the one setting CHANGING_FSID_V2) flag is being persisted on disk. This can cause the btrfs_fs_devices of this filesystem to be created by a device which: a) has the CHANGING_FSID_V2 flag set but its fsid value is intact b) or a device which doesn't have CHANGING_FSID_V2 flag set and its fsid value is intact This situation is trivially handled by the current find_fsid code since in both cases the devices are going to be treated like ordinary devices. Since btrfs is always mounted using the superblock of the latest device (the one with highest generation number), meaning it will have the CHANGING_FSID_V2 flag set, ensure it's being cleared on mount. On the first transaction commit following mount all disks will have it cleared. Signed-off-by: -
Nikolay Borisov authored
Currently btrfs_fs_info structure contains a copy of the fsid/metadata_uuid fields. Same values are also contained in the btrfs_fs_devices structure which fs_info has a reference to. Let's reduce duplication by removing the fields from fs_info and always refer to the ones in fs_devices. No functional changes. Signed-off-by:
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Nikolay Borisov authored
Since the metadata_uuid is a new incompat feature it requires the respective sysfs hooks. This patch adds the 'metdata_uuid' feature to be shown if it supported by the kernel. Additionally it adds /sys/fs/btrfs/UUID/metadata_uuid attribute which allows one to read the current metadata_uuid. Signed-off-by:
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Nikolay Borisov authored
This field is going to be used when the user wants to change the UUID of the filesystem without having to rewrite all metadata blocks. This field adds another level of indirection such that when the FSID is changed what really happens is the current UUID (the one with which the fs was created) is copied to the 'metadata_uuid' field in the superblock as well as a new incompat flag is set METADATA_UUID. When the kernel detects this flag is set it knows that the superblock in fact has 2 UUIDs: 1. Is the UUID which is user-visible, currently known as FSID. 2. Metadata UUID - this is the UUID which is stamped into all on-disk datastructures belonging to this file system. When the new incompat flag is present device scanning checks whether both fsid/metadata_uuid of the scanned device match any of the registered filesystems. When the flag is not set then both UUIDs are equal and only the FSID is retained on disk, metadata_uuid is set only in-memory during mount. Additionally a new metadata_uuid field is also added to the fs_info struct. It's initialised either with the FSID in case METADATA_UUID incompat flag is not set or with the metdata_uuid of the superblock otherwise. This commit introduces the new fields as well as the new incompat flag and switches all users of the fsid to the new logic. Signed-off-by:
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Johannes Thumshirn authored
Several functions in BTRFS are only used inside the source file they are declared if CONFIG_BTRFS_FS_RUN_SANITY_TESTS is not defined. However if CONFIG_BTRFS_FS_RUN_SANITY_TESTS is defined these functions are shared with the unit tests code. Before the introduction of the EXPORT_FOR_TESTS macro, these functions could not be declared as static and the compiler had a harder task when optimizing and inlining them. As we have EXPORT_FOR_TESTS now, use it where appropriate to support the compiler. Reviewed-by:
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Johannes Thumshirn authored
Depending on whether CONFIG_BTRFS_FS_RUN_SANITY_TESTS is set, some BTRFS functions are either local to the file they are implemented in and thus should be declared static or are called from within the test implementation defined in a different file. Introduce an EXPORT_FOR_TESTS macro which depending on CONFIG_BTRFS_FS_RUN_SANITY_TESTS either adds the 'static' keyword to a function or not. Reviewed-by:
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Johannes Thumshirn authored
Up to commit 32955c54 ("btrfs: switch to discard_new_inode()") the drop_on_err variable in btrfs_mkdir() was used to check whether the inode had to be dropped via iput(). After commit 32955c54 ("btrfs: switch to discard_new_inode()") discard_new_inode() is called when err is set and inode is non NULL. Therefore drop_on_err is not used anymore and thus causes a warning when building with -Wunused-but-set-variable. Reviewed-by:
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Nikolay Borisov authored
lock_delalloc_pages should only return 2 values - 0 in case of success and -EAGAIN if the range of pages to be locked should be shrunk due to some of gone. Manual inspections confirms that this is indeed the case since __process_pages_contig is where lock_delalloc_pages gets its return value. The latter always returns 0 or -EAGAIN so the invariant holds. No functional changes. Reviewed-by:
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Nikolay Borisov authored
All callers of this function pass BTRFS_MAX_EXTENT_SIZE (128M) so let's reduce the argument count and make that a local variable. No functional changes. Reviewed-by:
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Nikolay Borisov authored
It's unnecessary to check map->stripes[i].dev for NULL given its value is already set and dereferenced above the the check. No functional changes. Reviewed-by:
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