summaryrefslogtreecommitdiff
path: root/fs/btrfs/sysfs.c
AgeCommit message (Collapse)AuthorFilesLines
2020-03-23btrfs: sysfs: Use scnprintf() instead of snprintf()Takashi Iwai1-29/+28
snprintf() is a hard-to-use function, and it's especially difficult to use it properly for concatenating substrings in a buffer with a limited size. Since snprintf() returns the would-be-output size, not the actual size, the subsequent use of snprintf() may point to the incorrect position easily. Also, returning the value from snprintf() directly to sysfs show function would pass a bogus value that is higher than the actually truncated string. That said, although the current code doesn't actually overflow the buffer with PAGE_SIZE, it's a usage that shouldn't be done. Or it's worse; this gives a wrong confidence as if it were doing safe operations. This patch replaces such snprintf() calls with a safer version, scnprintf(). It returns the actual output size, hence it's more intuitive and the code does what's expected. Signed-off-by: Takashi Iwai <tiwai@suse.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: sysfs, unify handler name of devinfo/missingAnand Jain1-2/+2
The devinfo attribute handlers were added in 668e48af7a94 ("btrfs: sysfs, add devid/dev_state kobject and device attributes") and the name should contain _devinfo_, there's one that does not conform, so unify it with the rest. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: sysfs, rename device_link add/remove functionsAnand Jain1-5/+5
Since commit 668e48af7a94 ("btrfs: sysfs, add devid/dev_state kobject and device attributes"), the functions btrfs_sysfs_add_device_link() and btrfs_sysfs_rm_device_link() do more than just adding and removing the device link as its name indicated. Rename them to be more specific that's about the directory with the attirbutes Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: sysfs, use btrfs_sysfs_remove_fsid to celanup errors in add_fsidAnand Jain1-1/+1
We have one simple function btrfs_sysfs_remove_fsid() to undo btrfs_sysfs_add_fsid(), which also does proper checks before releasing objects. One difference, if btrfs_sysfs_remove_fsid is used that now we also call kobject_del() which was missing before. This was tested (with kobject debug turned on) and no change in behaviour was found. This is a cleanup patch. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-12btrfs: sysfs, move device id directories to UUID/devinfoAnand Jain1-1/+1
Originally it was planned to create device id directories under UUID/devinfo, but it got under UUID/devices by mistake. We really want it under definfo so the bare device node names are not mixed with device ids and are easy to enumerate. Fixes: 668e48af7a94 ("btrfs: sysfs, add devid/dev_state kobject and device attributes") Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-12btrfs: sysfs, add UUID/devinfo kobjectAnand Jain1-0/+15
Create directory /sys/fs/btrfs/UUID/devinfo to hold devices directories by the id (unlike /devices). Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23btrfs: sysfs, add devid/dev_state kobject and device attributesAnand Jain1-23/+132
New sysfs attributes that track the filesystem status of devices, stored in the per-filesystem directory in /sys/fs/btrfs/FSID/devinfo . There's a directory for each device, with name corresponding to the numerical device id. in_fs_metadata - device is in the list of fs metadata missing - device is missing (no device node or block device) replace_target - device is target of replace writeable - writes from fs are allowed These attributes reflect the state of the device::dev_state and created at mount time. Sample output: $ pwd /sys/fs/btrfs/6e1961f1-5918-4ecc-a22f-948897b409f7/devinfo/1/ $ ls in_fs_metadata missing replace_target writeable $ cat missing 0 The output from these attributes are 0 or 1. 0 indicates unset and 1 indicates set. These attributes are readonly. It is observed that the device delete thread and sysfs read thread will not race because the delete thread calls sysfs kobject_put() which in turn waits for existing sysfs read to complete. Note for device replace devid swap: During the replace the target device temporarily assumes devid 0 before assigning the devid of the soruce device. In btrfs_dev_replace_finishing() we remove source sysfs devid using the function btrfs_sysfs_remove_devices_attr(), so after that call kobject_rename() to update the devid in the sysfs. This adds and calls btrfs_sysfs_update_devid() helper function to update the device id. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20btrfs: keep track of discard reuse statsDennis Zhou1-0/+36
Keep track of how much we are discarding and how often we are reusing with async discard. The discard_*_bytes values don't need any special protection because the work item provides the single threaded access. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Dennis Zhou <dennis@kernel.org> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20btrfs: make max async discard size tunableDennis Zhou1-0/+31
Expose max_discard_size as a tunable via sysfs and switch the current fixed maximum to the default value. Signed-off-by: Dennis Zhou <dennis@kernel.org> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20btrfs: add kbps discard rate limit for async discardDennis Zhou1-0/+31
Provide the ability to rate limit based on kbps in addition to iops as additional guides for the target discard rate. The delay used ends up being max(kbps_delay, iops_delay). Signed-off-by: Dennis Zhou <dennis@kernel.org> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20btrfs: calculate discard delay based on number of extentsDennis Zhou1-0/+31
An earlier patch keeps track of discardable_extents. These are undiscarded extents managed by the free space cache. Here, we will use this to dynamically calculate the discard delay interval. There are 3 rate to consider. The first is the target convergence rate, the rate to discard all discardable_extents over the BTRFS_DISCARD_TARGET_MSEC time frame. This is clamped by the lower limit, the iops limit or BTRFS_DISCARD_MIN_DELAY (1ms), and the upper limit, BTRFS_DISCARD_MAX_DELAY (1s). We reevaluate this delay every transaction commit. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Dennis Zhou <dennis@kernel.org> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20btrfs: keep track of discardable_bytes for async discardDennis Zhou1-0/+12
Keep track of this metric so that we can understand how ahead or behind we are in discarding rate. This uses the same accounting method as discardable_extents, deltas between previous/current values and propagating them up. Signed-off-by: Dennis Zhou <dennis@kernel.org> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20btrfs: track discardable extents for async discardDennis Zhou1-0/+15
The number of discardable extents will serve as the rate limiting metric for how often we should discard. This keeps track of discardable extents in the free space caches by maintaining deltas and propagating them to the global count. The deltas are calculated from 2 values stored in PREV and CURR entries, then propagated up to the global discard ctl. The current counter value becomes the previous counter value after update. Signed-off-by: Dennis Zhou <dennis@kernel.org> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20btrfs: sysfs: add UUID/debug/discard directoryDennis Zhou1-0/+26
Setup base sysfs directory for discard stats + tunables. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Dennis Zhou <dennis@kernel.org> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20btrfs: sysfs: make UUID/debug have its own kobjectDennis Zhou1-4/+16
Btrfs only allowed attributes to be exposed in debug/. Let's let other groups be created by making debug its own kobject. This also makes the per-fs debug options separate from the global features mount attributes. This seems to be needed as sysfs_create_files() requires const struct attribute * while sysfs_create_group() can take struct attribute *. This seems nicer as per file system, you'll probably use to_fs_info(). Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Dennis Zhou <dennis@kernel.org> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20btrfs: sysfs: add removal calls for debug/Dennis Zhou1-0/+7
We probably should call sysfs_remove_group() on debug/. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Dennis Zhou <dennis@kernel.org> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20btrfs: sysfs, merge btrfs_sysfs_add devices_kobj and fsidAnand Jain1-12/+9
Merge btrfs_sysfs_add_fsid() and btrfs_sysfs_add_devices_kobj() functions as these two are small and they are called one after the other. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20btrfs: sysfs, rename btrfs_sysfs_add_device()Anand Jain1-1/+1
btrfs_sysfs_add_device() creates the directory /sys/fs/btrfs/UUID/devices but its function name is misleading. Rename it to btrfs_sysfs_add_devices_kobj() instead. No functional changes. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20btrfs: sysfs, btrfs_sysfs_add_fsid() drop unused argument parentAnand Jain1-5/+6
Commit 24bd69cb ("Btrfs: sysfs: add support to add parent for fsid") added parent argument in preparation to show the seed fsid under the sprout fsid as in the patch [1] in the mailing list. [1] Btrfs: sysfs: support seed devices in the sysfs layout But later this idea was superseded by another idea to rename the fsid as in the commit f93c39970b1d ("btrfs: factor out sysfs code for updating sprout fsid"). So we don't need parent argument anymore. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20btrfs: sysfs, rename devices kobject holder to devices_kobjAnand Jain1-14/+12
The struct member btrfs_device::device_dir_kobj holds the kobj of the sysfs directory /sys/fs/btrfs/UUID/devices, so rename it from device_dir_kobj to devices_kobj. No functional changes. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: rename btrfs_block_group_cacheDavid Sterba1-2/+2
The type name is misleading, a single entry is named 'cache' while this normally means a collection of objects. Rename that everywhere. Also the identifier was quite long, making function prototypes harder to format. Suggested-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: add incompat for raid1 with 3, 4 copiesDavid Sterba1-0/+2
The new raid1c3 and raid1c4 profiles are backward incompatible and the name shall be 'raid1c34', the status can be found in the global supported features in /sys/fs/btrfs/features or in the per-filesystem directory. Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: add dedicated members for start and length of a block groupDavid Sterba1-1/+1
The on-disk format of block group item makes use of the key that stores the offset and length. This is further used in the code, although this makes thing harder to understand. The key is also packed so the offset/length is not properly aligned as u64. Add start (key.objectid) and length (key.offset) members to block group and remove the embedded key. When the item is searched or written, a local variable for key is used. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: move block_group_item::used to block groupDavid Sterba1-1/+1
For unknown reasons, the member 'used' in the block group struct is stored in the b-tree item and accessed everywhere using the special accessor helper. Let's unify it and make it a regular member and only update the item before writing it to the tree. The item is still being used for flags and chunk_objectid, there's some duplication until the item is removed in following patches. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: sysfs: show used checksum driver per filesystemJohannes Thumshirn1-0/+15
Show the used driver for the checksum algorithm for the filesystem in sysfs file /sys/fs/btrfs/UUID/features/checksum, eg. crc32c (crc32c-generic) Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: sysfs: export supported checksumsDavid Sterba1-0/+22
Export supported checksum algorithms via sysfs in the list of static features: /sys/fs/btrfs/features/supported_checksums Space spearated list of checksum algorithm names. Co-developed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09btrfs: sysfs: move helper macros to sysfs.cDavid Sterba1-0/+48
None of the macros is used outside of sysfs.c. Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09btrfs: sysfs: move type conversion helpers to sysfs.cDavid Sterba1-0/+16
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09btrfs: cleanup kobject.h includesDavid Sterba1-1/+0
The kobject should be pulled in via sysfs.h and that needs to include it because it needs various definitions like kobj_attribute or kobject. Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09btrfs: factor out sysfs code for updating sprout fsidDavid Sterba1-0/+15
Wrap the fsid renaming code and move it to sysfs.c. Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09btrfs: factor out sysfs code for deleting block group and space infosDavid Sterba1-0/+22
The helpers to create block group and space info directories already live in sysfs.c, move the deletion part there too. Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09btrfs: factor out sysfs code for sending device ueventDavid Sterba1-0/+11
The device uevent belongs to the sysfs API. Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09btrfs: sysfs: replace direct access to feature set names with a helperDavid Sterba1-1/+6
In order to unexport the feature type array, add a helper for the enum-to-string conversion. Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09btrfs: sysfs: unexport space_info_ktypeDavid Sterba1-1/+1
The last non-sysfs usage of space_info_ktype has been moved to a private helper in previous patch so the variable can be made static. Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09btrfs: factor out sysfs code for creating space infosDavid Sterba1-0/+37
Move creation of data/metadata/system space info directories to sysfs.c. Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09btrfs: sysfs: unexport btrfs_raid_ktypeDavid Sterba1-1/+1
The last non-sysfs usage of btrfs_raid_ktype has been moved to a private helper in previous patch so the variable can be made static. Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09btrfs: factor sysfs code out of link_block_groupDavid Sterba1-0/+46
The part of link_block_group that just creates the sysfs object is independent and can be factored out to a helper. Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09btrfs: delete debugfs codeDavid Sterba1-30/+0
Replaced by the sysfs exports that provide a more fine grained interface for filesystem debugging. Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09btrfs: sysfs: add debugging exportsDavid Sterba1-0/+32
Add 'debug' directories to global sysfs and per-filesystem. This will replace the debugfs directory. The sysfs location is simpler and builds on top of the existing file hierarchy so there will hopefully be no more questions about the sample debugfs file. The directory is called 'debug' and only present under CONFIG_BTRFS_DEBUG so this will not affect productions builds. Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09btrfs: move basic block_group definitions to their own headerJosef Bacik1-0/+1
This is prep work for moving all of the block group cache code into its own file. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> [ minor comment updates ] Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-17Merge tag 'for-5.3-tag' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs updates from David Sterba: "Highlights: - chunks that have been trimmed and unchanged since last mount are tracked and skipped on repeated trims - use hw assissed crc32c on more arches, speedups if native instructions or optimized implementation is available - the RAID56 incompat bit is automatically removed when the last block group of that type is removed Fixes: - fsync fix for reflink on NODATACOW files that could lead to ENOSPC - fix data loss after inode eviction, renaming it, and fsync it - fix fsync not persisting dentry deletions due to inode evictions - update ctime/mtime/iversion after hole punching - fix compression type validation (reported by KASAN) - send won't be allowed to start when relocation is in progress, this can cause spurious errors or produce incorrect send stream Core: - new tracepoints for space update - tree-checker: better check for end of extents for some tree items - preparatory work for more checksum algorithms - run delayed iput at unlink time and don't push the work to cleaner thread where it's not properly throttled - wrap block mapping to structures and helpers, base for further refactoring - split large files, part 1: - space info handling - block group reservations - delayed refs - delayed allocation - other cleanups and refactoring" * tag 'for-5.3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (103 commits) btrfs: fix memory leak of path on error return path btrfs: move the subvolume reservation stuff out of extent-tree.c btrfs: migrate the delalloc space stuff to it's own home btrfs: migrate btrfs_trans_release_chunk_metadata btrfs: migrate the delayed refs rsv code btrfs: Evaluate io_tree in find_lock_delalloc_range() btrfs: migrate the global_block_rsv helpers to block-rsv.c btrfs: migrate the block-rsv code to block-rsv.c btrfs: stop using block_rsv_release_bytes everywhere btrfs: cleanup the target logic in __btrfs_block_rsv_release btrfs: export __btrfs_block_rsv_release btrfs: export btrfs_block_rsv_add_bytes btrfs: move btrfs_block_rsv definitions into it's own header btrfs: Simplify update of space_info in __reserve_metadata_bytes() btrfs: unexport can_overcommit btrfs: move reserve_metadata_bytes and supporting code to space-info.c btrfs: move dump_space_info to space-info.c btrfs: export block_rsv_use_bytes btrfs: move btrfs_space_info_add_*_bytes to space-info.c btrfs: move the space info update macro to space-info.h ...
2019-07-02btrfs: move space_info to space-info.hJosef Bacik1-0/+1
Migrate the struct definition and the one helper that's in ctree.h into space-info.h Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-06-21btrfs: sysfs: Replace default_attrs in ktypes with groupsKimberly Brown1-3/+5
The kobj_type default_attrs field is being replaced by the default_groups field. Replace the default_attrs fields in btrfs_raid_ktype and space_info_ktype with default_groups. Change "raid_attributes" to "raid_attrs", and use the ATTRIBUTE_GROUPS macro to create raid_groups and space_info_groups. Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com> Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-03btrfs: no need to check return value of debugfs_create functionsGreg Kroah-Hartman1-8/+2
When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: David Sterba <dsterba@suse.com> Cc: linux-btrfs@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-16btrfs: sysfs: don't leak memory when failing add fsidTobin C. Harding1-1/+6
A failed call to kobject_init_and_add() must be followed by a call to kobject_put(). Currently in the error path when adding fs_devices we are missing this call. This could be fixed by calling btrfs_sysfs_remove_fsid() if btrfs_sysfs_add_fsid() returns an error or by adding a call to kobject_put() directly in btrfs_sysfs_add_fsid(). Here we choose the second option because it prevents the slightly unusual error path handling requirements of kobject from leaking out into btrfs functions. Add a call to kobject_put() in the error path of kobject_add_and_init(). This causes the release method to be called if kobject_init_and_add() fails. open_tree() is the function that calls btrfs_sysfs_add_fsid() and the error code in this function is already written with the assumption that the release method is called during the error path of open_tree() (as seen by the call to btrfs_sysfs_remove_fsid() under the fail_fsdev_sysfs label). Cc: stable@vger.kernel.org # v4.4+ Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tobin C. Harding <tobin@kernel.org> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17btrfs: Add sysfs support for metadata_uuid featureNikolay Borisov1-0/+14
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: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: prune unused includesDavid Sterba1-2/+0
Remove includes if none of the interfaces and exports is used in the given source file. Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: sysfs: Add entry which shows if rmdir can work on subvolumesMisono Tomohiro1-0/+39
Deletion of a subvolume by rmdir(2) has become allowed by the 'commit cd2decf640b1 ("btrfs: Allow rmdir(2) to delete an empty subvolume")'. It is a kind of new feature and this commits add a sysfs entry /sys/fs/btrfs/features/rmdir_subvol to indicate the availability of the feature so that a user program (e.g. fstests) can detect it. Prior to this commit, all entries in /sys/fs/btrfs/features are feature which depend on feature bits of superblock (i.e. each feature affects on-disk format) and managed by attribute_group "btrfs_feature_attr_group". For each fs, entries in /sys/fs/btrfs/UUID/features indicate which features are enabled (or can be changed online) for the fs. However, rmdir_subvol feature only depends on kernel module. Therefore new attribute_group "btrfs_static_feature_attr_group" is introduced and sysfs_merge_group() is used to share /sys/fs/btrfs/features directory. Features in "btrfs_static_feature_attr_group" won't be listed in each /sys/fs/btrfs/UUID/features. Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: sysfs: Use enum/define value for feature array definitionsTomohiro Misono1-5/+6
Use existing named values instead of the raw numbers. Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: rename struct btrfs_fs_devices::listAnand Jain1-1/+1
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>