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authorDavid Howells <dhowells@redhat.com>2021-06-14 14:13:41 +0100
committerDavid Howells <dhowells@redhat.com>2021-06-21 21:23:36 +0100
commit66e9c6a86b800f60b1e1ea1ff7271f9e6ed1fa96 (patch)
tree9d12875d5d73cb8cfbc86c773e35e5fa150a7ff4
parent009c9aa5be652675a06d5211e1640e02bbb1c33d (diff)
afs: Fix afs_write_end() to handle short writes
Fix afs_write_end() to correctly handle a short copy into the intended write region of the page. Two things are necessary: (1) If the page is not up to date, then we should just return 0 (ie. indicating a zero-length copy). The loop in generic_perform_write() will go around again, possibly breaking up the iterator into discrete chunks[1]. This is analogous to commit b9de313cf05fe08fa59efaf19756ec5283af672a for ceph. (2) The page should not have been set uptodate if it wasn't completely set up by netfs_write_begin() (this will be fixed in the next patch), so we need to set uptodate here in such a case. Also remove the assertion that was checking that the page was set uptodate since it's now set uptodate if it wasn't already a few lines above. The assertion was from when uptodate was set elsewhere. Changes: v3: Remove the handling of len exceeding the end of the page. Fixes: 3003bbd0697b ("afs: Use the netfs_write_begin() helper") Reported-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> cc: Al Viro <viro@zeniv.linux.org.uk> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/YMwVp268KTzTf8cN@zeniv-ca.linux.org.uk/ [1] Link: https://lore.kernel.org/r/162367682522.460125.5652091227576721609.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/162391825688.1173366.3437507255136307904.stgit@warthog.procyon.org.uk/ # v2
-rw-r--r--fs/afs/write.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/fs/afs/write.c b/fs/afs/write.c
index a523bb86915d..641c54679399 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -118,6 +118,15 @@ int afs_write_end(struct file *file, struct address_space *mapping,
_enter("{%llx:%llu},{%lx}",
vnode->fid.vid, vnode->fid.vnode, page->index);
+ if (!PageUptodate(page)) {
+ if (copied < len) {
+ copied = 0;
+ goto out;
+ }
+
+ SetPageUptodate(page);
+ }
+
if (copied == 0)
goto out;
@@ -132,8 +141,6 @@ int afs_write_end(struct file *file, struct address_space *mapping,
write_sequnlock(&vnode->cb_lock);
}
- ASSERT(PageUptodate(page));
-
if (PagePrivate(page)) {
priv = page_private(page);
f = afs_page_dirty_from(page, priv);