[PATCH v4 10/39] netfs: Provide invalidate_folio and release_folio calls

David Howells
2023-12-13T15:24:50Z

Provide default invalidate_folio and release_folio calls. These will need
to interact with invalidation correctly at some point. They will be needed
if netfslib is to make use of folio->private for its own purposes.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
---
fs/9p/vfs_addr.c | 33 ++-------------------------
fs/afs/file.c | 53 ++++---------------------------------------
fs/ceph/addr.c | 24 ++------------------
fs/netfs/misc.c | 42 ++++++++++++++++++++++++++++++++++
include/linux/netfs.h | 6 +++--
5 files changed, 54 insertions(+), 104 deletions(-)

diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index 131b83c31f85..055b672a247d 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -88,35 +88,6 @@ const struct netfs_request_ops v9fs_req_ops = {
.issue_read = v9fs_issue_read,
};

-/**
- * v9fs_release_folio - release the private state associated with a folio
- * @folio: The folio to be released
- * @gfp: The caller's allocation restrictions
- *
- * Returns true if the page can be released, false otherwise.
- */
-
-static bool v9fs_release_folio(struct folio *folio, gfp_t gfp)
-{
- if (folio_test_private(folio))
- return false;
-#ifdef CONFIG_9P_FSCACHE
- if (folio_test_fscache(folio)) {
- if (current_is_kswapd() || !(gfp & __GFP_FS))
- return false;
- folio_wait_fscache(folio);
- }
- fscache_note_page_release(v9fs_inode_cookie(V9FS_I(folio_inode(folio))));
-#endif
- return true;
-}
-
-static void v9fs_invalidate_folio(struct folio *folio, size_t offset,
- size_t length)
-{
- folio_wait_fscache(folio);
-}
-
#ifdef CONFIG_9P_FSCACHE
static void v9fs_write_to_cache_done(void *priv, ssize_t transferred_or_error,
bool was_async)
@@ -324,8 +295,8 @@ const struct address_space_operations v9fs_addr_operations = {
.writepage = v9fs_vfs_writepage,
.write_begin = v9fs_write_begin,
.write_end = v9fs_write_end,
- .release_folio = v9fs_release_folio,
- .invalidate_folio = v9fs_invalidate_folio,
+ .release_folio = netfs_release_folio,
+ .invalidate_folio = netfs_invalidate_folio,
.launder_folio = v9fs_launder_folio,
.direct_IO = v9fs_direct_IO,
};
diff --git a/fs/afs/file.c b/fs/afs/file.c
index 5e2bca3b02fd..c5013ec3c1dc 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -20,9 +20,6 @@

static int afs_file_mmap(struct file *file, struct vm_area_struct *vma);
static int afs_symlink_read_folio(struct file *file, struct folio *folio);
-static void afs_invalidate_folio(struct folio *folio, size_t offset,
- size_t length);
-static bool afs_release_folio(struct folio *folio, gfp_t gfp_flags);

static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter);
static ssize_t afs_file_splice_read(struct file *in, loff_t *ppos,
@@ -57,8 +54,8 @@ const struct address_space_operations afs_file_aops = {
.readahead = netfs_readahead,
.dirty_folio = netfs_dirty_folio,
.launder_folio = afs_launder_folio,
- .release_folio = afs_release_folio,
- .invalidate_folio = afs_invalidate_folio,
+ .release_folio = netfs_release_folio,
+ .invalidate_folio = netfs_invalidate_folio,
.write_begin = afs_write_begin,
.write_end = afs_write_end,
.writepages = afs_writepages,
@@ -67,8 +64,8 @@ const struct address_space_operations afs_file_aops = {

const struct address_space_operations afs_symlink_aops = {
.read_folio = afs_symlink_read_folio,
- .release_folio = afs_release_folio,
- .invalidate_folio = afs_invalidate_folio,
+ .release_folio = netfs_release_folio,
+ .invalidate_folio = netfs_invalidate_folio,
.migrate_folio = filemap_migrate_folio,
};

@@ -383,48 +380,6 @@ const struct netfs_request_ops afs_req_ops = {
.issue_read = afs_issue_read,
};

-/*
- * invalidate part or all of a page
- * - release a page and clean up its private data if offset is 0 (indicating
- * the entire page)
- */
-static void afs_invalidate_folio(struct folio *folio, size_t offset,
- size_t length)
-{
- _enter("{%lu},%zu,%zu", folio->index, offset, length);
-
- folio_wait_fscache(folio);
- _leave("");
-}
-
-/*
- * release a page and clean up its private state if it's not busy
- * - return true if the page can now be released, false if not
- */
-static bool afs_release_folio(struct folio *folio, gfp_t gfp)
-{
- struct afs_vnode *vnode = AFS_FS_I(folio_inode(folio));
-
- _enter("{{%llx:%llu}[%lu],%lx},%x",
- vnode->fid.vid, vnode->fid.vnode, folio_index(folio), folio->flags,
- gfp);
-
- /* deny if folio is being written to the cache and the caller hasn't
- * elected to wait */
-#ifdef CONFIG_AFS_FSCACHE
- if (folio_test_fscache(folio)) {
- if (current_is_kswapd() || !(gfp & __GFP_FS))
- return false;
- folio_wait_fscache(folio);
- }
- fscache_note_page_release(afs_vnode_cache(vnode));
-#endif
-
- /* Indicate that the folio can be released */
- _leave(" = T");
- return true;
-}
-
static void afs_add_open_mmap(struct afs_vnode *vnode)
{
if (atomic_inc_return(&vnode->cb_nr_mmap) == 1) {
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 654f408a0aca..500a87b68a9a 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -159,27 +159,7 @@ static void ceph_invalidate_folio(struct folio *folio, size_t offset,
ceph_put_snap_context(snapc);
}

- folio_wait_fscache(folio);
-}
-
-static bool ceph_release_folio(struct folio *folio, gfp_t gfp)
-{
- struct inode *inode = folio->mapping->host;
- struct ceph_client *cl = ceph_inode_to_client(inode);
-
- doutc(cl, "%llx.%llx idx %lu (%sdirty)\n", ceph_vinop(inode),
- folio->index, folio_test_dirty(folio) ? "" : "not ");
-
- if (folio_test_private(folio))
- return false;
-
- if (folio_test_fscache(folio)) {
- if (current_is_kswapd() || !(gfp & __GFP_FS))
- return false;
- folio_wait_fscache(folio);
- }
- ceph_fscache_note_page_release(inode);
- return true;
+ netfs_invalidate_folio(folio, offset, length);
}

static void ceph_netfs_expand_readahead(struct netfs_io_request *rreq)
@@ -1585,7 +1565,7 @@ const struct address_space_operations ceph_aops = {
.write_end = ceph_write_end,
.dirty_folio = ceph_dirty_folio,
.invalidate_folio = ceph_invalidate_folio,
- .release_folio = ceph_release_folio,
+ .release_folio = netfs_release_folio,
.direct_IO = noop_direct_IO,
};

diff --git a/fs/netfs/misc.c b/fs/netfs/misc.c
index 68baf55c47a4..d946d85764de 100644
--- a/fs/netfs/misc.c
+++ b/fs/netfs/misc.c
@@ -84,3 +84,45 @@ void netfs_clear_inode_writeback(struct inode *inode, const void *aux)
}
}
EXPORT_SYMBOL(netfs_clear_inode_writeback);
+
+/*
+ * netfs_invalidate_folio - Invalidate or partially invalidate a folio
+ * @folio: Folio proposed for release
+ * @offset: Offset of the invalidated region
+ * @length: Length of the invalidated region
+ *
+ * Invalidate part or all of a folio for a network filesystem. The folio will
+ * be removed afterwards if the invalidated region covers the entire folio.
+ */
+void netfs_invalidate_folio(struct folio *folio, size_t offset, size_t length)
+{
+ _enter("{%lx},%zx,%zx", folio_index(folio), offset, length);
+
+ folio_wait_fscache(folio);
+}
+EXPORT_SYMBOL(netfs_invalidate_folio);
+
+/**
+ * netfs_release_folio - Try to release a folio
+ * @folio: Folio proposed for release
+ * @gfp: Flags qualifying the release
+ *
+ * Request release of a folio and clean up its private state if it's not busy.
+ * Returns true if the folio can now be released, false if not
+ */
+bool netfs_release_folio(struct folio *folio, gfp_t gfp)
+{
+ struct netfs_inode *ctx = netfs_inode(folio_inode(folio));
+
+ if (folio_test_private(folio))
+ return false;
+ if (folio_test_fscache(folio)) {
+ if (current_is_kswapd() || !(gfp & __GFP_FS))
+ return false;
+ folio_wait_fscache(folio);
+ }
+
+ fscache_note_page_release(netfs_i_cookie(ctx));
+ return true;
+}
+EXPORT_SYMBOL(netfs_release_folio);
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 06f57d9d09f6..8efbfd3b2820 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -293,11 +293,13 @@ struct readahead_control;
void netfs_readahead(struct readahead_control *);
int netfs_read_folio(struct file *, struct folio *);
int netfs_write_begin(struct netfs_inode *, struct file *,
- struct address_space *, loff_t pos, unsigned int len,
- struct folio **, void **fsdata);
+ struct address_space *, loff_t pos, unsigned int len,
+ struct folio **, void **fsdata);
bool netfs_dirty_folio(struct address_space *mapping, struct folio *folio);
int netfs_unpin_writeback(struct inode *inode, struct writeback_control *wbc);
void netfs_clear_inode_writeback(struct inode *inode, const void *aux);
+void netfs_invalidate_folio(struct folio *folio, size_t offset, size_t length);
+bool netfs_release_folio(struct folio *folio, gfp_t gfp);

void netfs_subreq_terminated(struct netfs_io_subrequest *, ssize_t, bool);
void netfs_get_subrequest(struct netfs_io_subrequest *subreq,