PG_fscache is going to be used to indicate that a page is being written to
the cache, and that the page should not be modified or released until it's
finished.
Make afs_invalidatepage() and afs_releasepage() wait for it.
Signed-off-by: David Howells <dhowe...@redhat.com>
---
fs/afs/file.c | 13 +++++++++++++
fs/afs/write.c | 9 +++++++++
2 files changed, 22 insertions(+)
diff --git a/fs/afs/file.c b/fs/afs/file.c
index ea9f6d45d9ff..b25c5ab1f4e1 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -548,6 +548,11 @@ static void afs_invalidatepage(struct page *page, unsigned
int offset,
/* we clean up only if the entire page is being invalidated */
if (offset == 0 && length == PAGE_SIZE) {
+#ifdef CONFIG_AFS_FSCACHE
+ if (PageFsCache(page))
+ wait_on_page_fscache(page);
+#endif
+
if (PagePrivate(page)) {
priv = page_private(page);
trace_afs_page_dirty(vnode, tracepoint_string("inval"),
@@ -575,6 +580,14 @@ static int afs_releasepage(struct page *page, gfp_t
gfp_flags)
/* deny if page is being written to the cache and the caller hasn't
* elected to wait */
+#ifdef CONFIG_AFS_FSCACHE
+ if (PageFsCache(page)) {
+ if (!(gfp_flags & __GFP_DIRECT_RECLAIM) || !(gfp_flags &
__GFP_FS))
+ return false;
+ wait_on_page_fscache(page);
+ }
+#endif
+
if (PagePrivate(page)) {
priv = page_private(page);
trace_afs_page_dirty(vnode, tracepoint_string("rel"),
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 390fee44446c..3632909fcd91 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -111,6 +111,10 @@ int afs_write_begin(struct file *file, struct
address_space *mapping,
SetPageUptodate(page);
}
+#ifdef CONFIG_AFS_FSCACHE
+ wait_on_page_fscache(page);
+#endif
+
/* page won't leak in error case: it eventually gets cleaned off LRU */
*pagep = page;
@@ -786,6 +790,11 @@ vm_fault_t afs_page_mkwrite(struct vm_fault *vmf)
/* Wait for the page to be written to the cache before we allow it to
* be modified. We then assume the entire page will need writing back.
*/
+#ifdef CONFIG_AFS_FSCACHE
+ if (PageFsCache(vmf->page) &&
+ wait_on_page_bit_killable(vmf->page, PG_fscache) < 0)
+ return VM_FAULT_RETRY;
+#endif
if (PageWriteback(vmf->page) &&
wait_on_page_bit_killable(vmf->page, PG_writeback) < 0)
