6.10-stable review patch. If anyone has any objections, please let me know.
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From: David Howells dhowells@redhat.com
[ Upstream commit a74ee0e878e262c0276966528d72d4e887174410 ]
At the end of an kAFS RPC operation, there is an "edit" phase (originally intended for post-directory modification ops to edit the local image) that the setattr VFS op uses to fix up the pagecache if the RPC that requested truncation of a file was successful.
afs_setattr_edit_file() calls truncate_setsize() which sets i_size, expands the pagecache if needed and truncates the pagecache. The first two of those, however, are redundant as they've already been done by afs_setattr_success() under the io_lock and the first is also done under the callback lock (cb_lock).
Fix afs_setattr_edit_file() to call truncate_pagecache() instead (which is called by truncate_setsize(), thereby skipping the redundant parts.
Fixes: 100ccd18bb41 ("netfs: Optimise away reads above the point at which there can be no data") Signed-off-by: David Howells dhowells@redhat.com Link: https://lore.kernel.org/r/20240823200819.532106-3-dhowells@redhat.com cc: Matthew Wilcox (Oracle) willy@infradead.org cc: Pankaj Raghav p.raghav@samsung.com cc: Jeff Layton jlayton@kernel.org cc: Marc Dionne marc.dionne@auristor.com cc: linux-afs@lists.infradead.org cc: netfs@lists.linux.dev cc: linux-mm@kvack.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner brauner@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/afs/inode.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/fs/afs/inode.c b/fs/afs/inode.c index 3acf5e0500728..a95e77670b494 100644 --- a/fs/afs/inode.c +++ b/fs/afs/inode.c @@ -695,13 +695,18 @@ static void afs_setattr_edit_file(struct afs_operation *op) { struct afs_vnode_param *vp = &op->file[0]; struct afs_vnode *vnode = vp->vnode; + struct inode *inode = &vnode->netfs.inode;
if (op->setattr.attr->ia_valid & ATTR_SIZE) { loff_t size = op->setattr.attr->ia_size; - loff_t i_size = op->setattr.old_i_size; + loff_t old = op->setattr.old_i_size; + + /* Note: inode->i_size was updated by afs_apply_status() inside + * the I/O and callback locks. + */
- if (size != i_size) { - truncate_setsize(&vnode->netfs.inode, size); + if (size != old) { + truncate_pagecache(inode, size); netfs_resize_file(&vnode->netfs, size, true); fscache_resize_cookie(afs_vnode_cache(vnode), size); }