xfs: add file_{get,put}_folio

Add helper similar to file_{get,set}_page, but which deal with folios
and don't allocate new folio unless explicitly asked to, which map
to shmem_get_folio instead of calling into the aops.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
This commit is contained in:
Darrick J. Wong 2024-02-19 07:27:26 +01:00 committed by Chandan Babu R
parent e97d70a573
commit 6907e3c00a
3 changed files with 83 additions and 0 deletions

View File

@ -908,6 +908,8 @@ DEFINE_XFILE_EVENT(xfile_store);
DEFINE_XFILE_EVENT(xfile_seek_data);
DEFINE_XFILE_EVENT(xfile_get_page);
DEFINE_XFILE_EVENT(xfile_put_page);
DEFINE_XFILE_EVENT(xfile_get_folio);
DEFINE_XFILE_EVENT(xfile_put_folio);
TRACE_EVENT(xfarray_create,
TP_PROTO(struct xfarray *xfa, unsigned long long required_capacity),

View File

@ -340,3 +340,77 @@ xfile_put_page(
return -EIO;
return 0;
}
/*
* Grab the (locked) folio for a memory object. The object cannot span a folio
* boundary. Returns the locked folio if successful, NULL if there was no
* folio or it didn't cover the range requested, or an ERR_PTR on failure.
*/
struct folio *
xfile_get_folio(
struct xfile *xf,
loff_t pos,
size_t len,
unsigned int flags)
{
struct inode *inode = file_inode(xf->file);
struct folio *folio = NULL;
unsigned int pflags;
int error;
if (inode->i_sb->s_maxbytes - pos < len)
return ERR_PTR(-ENOMEM);
trace_xfile_get_folio(xf, pos, len);
/*
* Increase the file size first so that shmem_get_folio(..., SGP_CACHE),
* actually allocates a folio instead of erroring out.
*/
if ((flags & XFILE_ALLOC) && pos + len > i_size_read(inode))
i_size_write(inode, pos + len);
pflags = memalloc_nofs_save();
error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
(flags & XFILE_ALLOC) ? SGP_CACHE : SGP_READ);
memalloc_nofs_restore(pflags);
if (error)
return ERR_PTR(error);
if (!folio)
return NULL;
if (len > folio_size(folio) - offset_in_folio(folio, pos)) {
folio_unlock(folio);
folio_put(folio);
return NULL;
}
if (filemap_check_wb_err(inode->i_mapping, 0)) {
folio_unlock(folio);
folio_put(folio);
return ERR_PTR(-EIO);
}
/*
* Mark the folio dirty so that it won't be reclaimed once we drop the
* (potentially last) reference in xfile_put_folio.
*/
if (flags & XFILE_ALLOC)
folio_set_dirty(folio);
return folio;
}
/*
* Release the (locked) folio for a memory object.
*/
void
xfile_put_folio(
struct xfile *xf,
struct folio *folio)
{
trace_xfile_put_folio(xf, folio_pos(folio), folio_size(folio));
folio_unlock(folio);
folio_put(folio);
}

View File

@ -39,4 +39,11 @@ int xfile_get_page(struct xfile *xf, loff_t offset, unsigned int len,
struct xfile_page *xbuf);
int xfile_put_page(struct xfile *xf, struct xfile_page *xbuf);
#define XFILE_MAX_FOLIO_SIZE (PAGE_SIZE << MAX_PAGECACHE_ORDER)
#define XFILE_ALLOC (1 << 0) /* allocate folio if not present */
struct folio *xfile_get_folio(struct xfile *xf, loff_t offset, size_t len,
unsigned int flags);
void xfile_put_folio(struct xfile *xf, struct folio *folio);
#endif /* __XFS_SCRUB_XFILE_H__ */