kernel.git/fs/btrfs/sysfs.c, branch linux-6.3.y

btrfs: sysfs: add size class stats

2023-03-01T18:27:20Z

Make it possible to see the distribution of size classes for block groups. Helpful for testing and debugging the allocator w.r.t. to size classes. The new stats can be found at the path: /sys/fs/btrfs//allocation//size_class but they will only be non-zero for bg-type = data. Signed-off-by: Boris Burkov Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: make kobj_type structures constant

2023-02-15T18:38:55Z

Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.") the driver core allows the usage of const struct kobj_type. Take advantage of this to constify the structure definitions to prevent modification at runtime. Reviewed-by: Anand Jain Signed-off-by: Thomas Weißschuh Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: sysfs: update fs features directory asynchronously

2023-02-13T16:50:35Z

[BUG] Since the introduction of per-fs feature sysfs interface (/sys/fs/btrfs//features/), the content of that directory is never updated. Thus for the following case, that directory will not show the new features like RAID56: # mkfs.btrfs -f $dev1 $dev2 $dev3 # mount $dev1 $mnt # btrfs balance start -f -mconvert=raid5 $mnt # ls /sys/fs/btrfs/$uuid/features/ extended_iref free_space_tree no_holes skinny_metadata While after unmount and mount, we got the correct features: # umount $mnt # mount $dev1 $mnt # ls /sys/fs/btrfs/$uuid/features/ extended_iref free_space_tree no_holes raid56 skinny_metadata [CAUSE] Because we never really try to update the content of per-fs features/ directory. We had an attempt to update the features directory dynamically in commit 14e46e04958d ("btrfs: synchronize incompat feature bits with sysfs files"), but unfortunately it get reverted in commit e410e34fad91 ("Revert "btrfs: synchronize incompat feature bits with sysfs files""). The problem in the original patch is, in the context of btrfs_create_chunk(), we can not afford to update the sysfs group. The exported but never utilized function, btrfs_sysfs_feature_update() is the leftover of such attempt. As even if we go sysfs_update_group(), new files will need extra memory allocation, and we have no way to specify the sysfs update to go GFP_NOFS. [FIX] This patch will address the old problem by doing asynchronous sysfs update in the cleaner thread. This involves the following changes: - Make __btrfs_(set|clear)_fs_(incompat|compat_ro) helpers to set BTRFS_FS_FEATURE_CHANGED flag when needed - Update btrfs_sysfs_feature_update() to use sysfs_update_group() And drop unnecessary arguments. - Call btrfs_sysfs_feature_update() in cleaner_kthread If we have the BTRFS_FS_FEATURE_CHANGED flag set. - Wake up cleaner_kthread in btrfs_commit_transaction if we have BTRFS_FS_FEATURE_CHANGED flag By this, all the previously dangerous call sites like btrfs_create_chunk() need no new changes, as above helpers would have already set the BTRFS_FS_FEATURE_CHANGED flag. The real work happens at cleaner_kthread, thus we pay the cost of delaying the update to sysfs directory, but the delayed time should be small enough that end user can not distinguish though it might get delayed if the cleaner thread is busy with removing subvolumes or defrag. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Anand Jain Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: simplify percent calculation helpers, rename div_factor

2022-12-05T17:00:48Z

The div_factor* helpers calculate fraction or percentage fraction. The name is a bit confusing, we use it only for percentage calculations and there are two helpers. There's a helper mult_frac that's for general fractions, that tries to be accurate but we multiply and divide by small numbers so we can use the div_u64 helper. Rename the div_factor* helpers and use 1..100 percentage range, also drop the case checking for percentage == 100, it's never hit. The conversions: * div_factor calculates tenths and the numbers need to be adjusted * div_factor_fine is direct replacement Signed-off-by: David Sterba

btrfs: move accessor helpers into accessors.h

2022-12-05T17:00:42Z

This is a large patch, but because they're all macros it's impossible to split up. Simply copy all of the item accessors in ctree.h and paste them in accessors.h, and then update any files to include the header so everything compiles. Reviewed-by: Anand Jain Signed-off-by: Josef Bacik Reviewed-by: David Sterba [ reformat comments, style fixups ] Signed-off-by: David Sterba

btrfs: add a BTRFS_FS_NEED_TRANS_COMMIT flag

2022-12-05T17:00:42Z

Currently we are only using fs_info->pending_changes to indicate that we need a transaction commit. The original users for this were removed years ago and we don't have more usage in sight, so this is the only remaining reason to have this field. Add a flag so we can remove this code. Reviewed-by: Johannes Thumshirn Reviewed-by: Anand Jain Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: move BTRFS_FS_STATE* definitions and helpers to fs.h

2022-12-05T17:00:42Z

We're going to use fs.h to hold fs wide related helpers and definitions, move the FS_STATE enum and related helpers to fs.h, and then update all files that need these definitions to include fs.h. Reviewed-by: Johannes Thumshirn Reviewed-by: Anand Jain Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: move the printk helpers out of ctree.h

2022-12-05T17:00:41Z

We have a bunch of printk helpers that are in ctree.h. These have nothing to do with ctree.c, so move them into their own header. Subsequent patches will cleanup the printk helpers. Reviewed-by: Johannes Thumshirn Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: sysfs: convert remaining scnprintf to sysfs_emit

2022-12-05T17:00:41Z

The sysfs_emit is the safe API for writing to the sysfs files, previously converted from scnprintf, there's one left to do in btrfs_read_policy_show. Reviewed-by: Johannes Thumshirn Reviewed-by: Josef Bacik Signed-off-by: David Sterba

btrfs: sysfs: normalize the error handling branch in btrfs_init_sysfs()

2022-11-23T15:52:22Z

Although kset_unregister() can eventually remove all attribute files, explicitly rolling back with the matching function makes the code logic look clearer. CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Qu Wenruo Signed-off-by: Zhen Lei Reviewed-by: David Sterba Signed-off-by: David Sterba