iomap/gfs2: Get page in page_prepare handler
Change the iomap ->page_prepare() handler to get and return a locked
folio instead of doing that in iomap_write_begin(). This allows to
recover from out-of-memory situations in ->page_prepare(), which
eliminates the corresponding error handling code in iomap_write_begin().
The ->put_folio() handler now also isn't called with NULL as the folio
value anymore.
Filesystems are expected to use the iomap_get_folio() helper for getting
locked folios in their ->page_prepare() handlers.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 0c04145..41349e0 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -956,15 +956,25 @@ static int __gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length,
goto out;
}
-static int gfs2_iomap_page_prepare(struct inode *inode, loff_t pos,
- unsigned len)
+static struct folio *
+gfs2_iomap_page_prepare(struct iomap_iter *iter, loff_t pos, unsigned len)
{
+ struct inode *inode = iter->inode;
unsigned int blockmask = i_blocksize(inode) - 1;
struct gfs2_sbd *sdp = GFS2_SB(inode);
unsigned int blocks;
+ struct folio *folio;
+ int status;
blocks = ((pos & blockmask) + len + blockmask) >> inode->i_blkbits;
- return gfs2_trans_begin(sdp, RES_DINODE + blocks, 0);
+ status = gfs2_trans_begin(sdp, RES_DINODE + blocks, 0);
+ if (status)
+ return ERR_PTR(status);
+
+ folio = iomap_get_folio(iter, pos);
+ if (IS_ERR(folio))
+ gfs2_trans_end(sdp);
+ return folio;
}
static void gfs2_iomap_put_folio(struct inode *inode, loff_t pos,
@@ -974,11 +984,6 @@ static void gfs2_iomap_put_folio(struct inode *inode, loff_t pos,
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_sbd *sdp = GFS2_SB(inode);
- if (!folio) {
- gfs2_trans_end(sdp);
- return;
- }
-
if (!gfs2_is_stuffed(ip))
gfs2_page_add_databufs(ip, &folio->page, offset_in_page(pos),
copied);
