kernel/git/stable/linux.git/fs/btrfs/sysfs.c, branch linux-4.18.y

btrfs: sysfs: Add entry which shows if rmdir can work on subvolumes

2018-05-28T16:23:41+00:00

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 Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: sysfs: Use enum/define value for feature array definitions

2018-05-28T16:23:39+00:00

Use existing named values instead of the raw numbers. Signed-off-by: Tomohiro Misono Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: rename struct btrfs_fs_devices::list

2018-05-28T16:07:21+00:00

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 Signed-off-by: David Sterba

btrfs: replace GPL boilerplate by SPDX -- sources

2018-04-12T14:29:51+00:00

Remove GPL boilerplate text (long, short, one-line) and keep the rest, ie. personal, company or original source copyright statements. Add the SPDX header. Signed-off-by: David Sterba

btrfs: defer adding raid type kobject until after chunk relocation

2018-03-30T23:41:12+00:00

Any time the first block group of a new type is created, we add a new kobject to sysfs to hold the attributes for that type. Kobject-internal allocations always use GFP_KERNEL, making them prone to fs-reclaim races. While it appears as if this can occur any time a block group is created, the only times the first block group of a new type can be created in memory is at mount and when we create the first new block group during raid conversion. This patch adds a new list to track pending kobject additions and then handles them after we do chunk relocation. Between relocating the target chunk (or forcing allocation of a new chunk in the case of data) and removing the old chunk, we're in a safe place for fs-reclaim to occur. We're holding the volume mutex, which is already held across page faults, and the delete_unused_bgs_mutex, which will only stall the cleaner thread. Signed-off-by: Jeff Mahoney Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: add more __cold annotations

2018-03-26T13:09:39+00:00

The __cold functions are placed to a special section, as they're expected to be called rarely. This could help i-cache prefetches or help compiler to decide which branches are more/less likely to be taken without any other annotations needed. Though we can't add more __exit annotations, it's still possible to add __cold (that's also added with __exit). That way the following function categories are tagged: - printf wrappers, error messages - exit helpers Signed-off-by: David Sterba

Revert "btrfs: use proper endianness accessors for super_copy"

2018-03-16T13:49:44+00:00

This reverts commit 3c181c12c431fe33b669410d663beb9cceefcd1b. The offending patch was merged in 4.16-rc4 and was promptly applied to stable kernels 4.14.25 and 4.15.8. The patch causes a corruption in several superblock items on big-endian machines because of messed up endianity conversions. The damage is manually repairable. A filesystem cannot be mounted again after it has been unmounted once. We do a full revert and not a fixup so stable can pick that patch ASAP. Fixes: 3c181c12c431 ("btrfs: use proper endianness accessors for super_copy") Link: https://lkml.kernel.org/r/1521139304@msgid.manchmal.in-ulm.de CC: stable@vger.kernel.org # 4.14+ Reported-by: Christoph Biedl Signed-off-by: David Sterba

btrfs: use proper endianness accessors for super_copy

2018-03-01T15:17:27+00:00

The fs_info::super_copy is a byte copy of the on-disk structure and all members must use the accessor macros/functions to obtain the right value. This was missing in update_super_roots and in sysfs readers. Moving between opposite endianness hosts will report bogus numbers in sysfs, and mount may fail as the root will not be restored correctly. If the filesystem is always used on a same endian host, this will not be a problem. Fix this by using the btrfs_set_super...() functions to set fs_info::super_copy values, and for the sysfs, use the cached fs_info::nodesize/sectorsize values. CC: stable@vger.kernel.org Fixes: df93589a17378 ("btrfs: export more from FS_INFO to sysfs") Signed-off-by: Anand Jain Reviewed-by: Liu Bo Reviewed-by: David Sterba [ update changelog ] Signed-off-by: David Sterba

Btrfs: add __init macro to btrfs init functions

2018-01-22T15:08:11+00:00

Adding __init macro gives kernel a hint that this function is only used during the initialization phase and its memory resources can be freed up after. Signed-off-by: Liu Bo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: prefix sysfs attribute struct names

2017-10-30T11:27:58+00:00

Currently struct names for sysfs are generated only based on the attribute names. This means that attribute names cannot be reused in multiple places throughout the complete btrfs sysfs hierarchy. E.g. allocation/data/total_bytes and allocation/data/single/total_bytes result in the same struct name btrfs_attr_total_bytes. A workaround for this case was made in the past by ad hoc creating an extra macro wrapper, BTRFS_RAID_ATTR, that inserts some extra text in the struct name. Instead of polluting sysfs.h with such kind of extra macro definitions, and only doing so when there are collisions, use a prefix which gets inserted in the struct name, so we keep everything nicely grouped together by default. Current collections of attributes are: * (the toplevel, empty prefix) * allocation * space_info * raid * features Signed-off-by: Hans van Kranenburg Reviewed-by: David Sterba Signed-off-by: David Sterba