On 2025/5/5 22:29, Darrick J. Wong wrote: > On Mon, May 05, 2025 at 03:22:08PM +0200, Christoph Hellwig wrote: >> On Mon, Apr 21, 2025 at 10:15:05AM +0800, Zhang Yi wrote: >>> From: Zhang Yi <yi.zh...@huawei.com> >>> >>> Add a new attribute flag to statx to determine whether a bdev or a file >>> supports the unmap write zeroes command. >>> >>> Signed-off-by: Zhang Yi <yi.zh...@huawei.com> >>> --- >>> block/bdev.c | 4 ++++ >>> fs/ext4/inode.c | 9 ++++++--- >>> include/uapi/linux/stat.h | 1 + >>> 3 files changed, 11 insertions(+), 3 deletions(-) >>> >>> diff --git a/block/bdev.c b/block/bdev.c >>> index 4844d1e27b6f..29b0e5feb138 100644 >>> --- a/block/bdev.c >>> +++ b/block/bdev.c >>> @@ -1304,6 +1304,10 @@ void bdev_statx(struct path *path, struct kstat >>> *stat, >>> queue_atomic_write_unit_max_bytes(bd_queue)); >>> } >>> >>> + if (bdev_write_zeroes_unmap(bdev)) >>> + stat->attributes |= STATX_ATTR_WRITE_ZEROES_UNMAP; >>> + stat->attributes_mask |= STATX_ATTR_WRITE_ZEROES_UNMAP; >> >> Hmm, shouldn't this always be set by stat? But I might just be >> really confused what attributes_mask is, and might in fact have >> misapplied it in past patches of my own.. > > attributes_mask contains attribute flags known to the filesystem, > whereas attributes contains flags actually set on the file. > "known_attributes" would have been a better name, but that's water under > the bridge. :P > >> Also shouldn't the patches to report the flag go into the bdev/ext4 >> patches that actually implement the feature for the respective files >> to keep bisectability? > > /I/ think so... >
OK, since this statx reporting flag is not strongly tied to FALLOC_FL_WRITE_ZEROES in vfs_fallocate(), I'll split this patch into three separate patches. Thanks, Yi.
