xfs: enable discarding of folios backing an xfile

Create a new xfile function to discard the page cache that's backing
part of an xfile.  The next patch wil use this to drop parts of an xfile
that aren't needed anymore.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Darrick J. Wong 2024-04-15 14:54:42 -07:00
parent fe6c9f8e48
commit 98339edf07
3 changed files with 14 additions and 0 deletions

View File

@ -948,6 +948,7 @@ DEFINE_XFILE_EVENT(xfile_store);
DEFINE_XFILE_EVENT(xfile_seek_data);
DEFINE_XFILE_EVENT(xfile_get_folio);
DEFINE_XFILE_EVENT(xfile_put_folio);
DEFINE_XFILE_EVENT(xfile_discard);
TRACE_EVENT(xfarray_create,
TP_PROTO(struct xfarray *xfa, unsigned long long required_capacity),

View File

@ -310,3 +310,15 @@ xfile_put_folio(
folio_unlock(folio);
folio_put(folio);
}
/* Discard the page cache that's backing a range of the xfile. */
void
xfile_discard(
struct xfile *xf,
loff_t pos,
u64 count)
{
trace_xfile_discard(xf, pos, count);
shmem_truncate_range(file_inode(xf->file), pos, pos + count - 1);
}

View File

@ -17,6 +17,7 @@ int xfile_load(struct xfile *xf, void *buf, size_t count, loff_t pos);
int xfile_store(struct xfile *xf, const void *buf, size_t count,
loff_t pos);
void xfile_discard(struct xfile *xf, loff_t pos, u64 count);
loff_t xfile_seek_data(struct xfile *xf, loff_t pos);
#define XFILE_MAX_FOLIO_SIZE (PAGE_SIZE << MAX_PAGECACHE_ORDER)