Merge tag 'vfs-6.8.netfs' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs

Pull netfs updates from Christian Brauner:
 "This extends the netfs helper library that network filesystems can use
  to replace their own implementations. Both afs and 9p are ported. cifs
  is ready as well but the patches are way bigger and will be routed
  separately once this is merged. That will remove lots of code as well.

  The overal goal is to get high-level I/O and knowledge of the page
  cache and ouf of the filesystem drivers. This includes knowledge about
  the existence of pages and folios

  The pull request converts afs and 9p. This removes about 800 lines of
  code from afs and 300 from 9p. For 9p it is now possible to do writes
  in larger than a page chunks. Additionally, multipage folio support
  can be turned on for 9p. Separate patches exist for cifs removing
  another 2000+ lines. I've included detailed information in the
  individual pulls I took.

  Summary:

   - Add NFS-style (and Ceph-style) locking around DIO vs buffered I/O
     calls to prevent these from happening at the same time.

   - Support for direct and unbuffered I/O.

   - Support for write-through caching in the page cache.

   - O_*SYNC and RWF_*SYNC writes use write-through rather than writing
     to the page cache and then flushing afterwards.

   - Support for write-streaming.

   - Support for write grouping.

   - Skip reads for which the server could only return zeros or EOF.

   - The fscache module is now part of the netfs library and the
     corresponding maintainer entry is updated.

   - Some helpers from the fscache subsystem are renamed to mark them as
     belonging to the netfs library.

   - Follow-up fixes for the netfs library.

   - Follow-up fixes for the 9p conversion"

* tag 'vfs-6.8.netfs' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (50 commits)
  netfs: Fix wrong #ifdef hiding wait
  cachefiles: Fix signed/unsigned mixup
  netfs: Fix the loop that unmarks folios after writing to the cache
  netfs: Fix interaction between write-streaming and cachefiles culling
  netfs: Count DIO writes
  netfs: Mark netfs_unbuffered_write_iter_locked() static
  netfs: Fix proc/fs/fscache symlink to point to "netfs" not "../netfs"
  netfs: Rearrange netfs_io_subrequest to put request pointer first
  9p: Use length of data written to the server in preference to error
  9p: Do a couple of cleanups
  9p: Fix initialisation of netfs_inode for 9p
  cachefiles: Fix __cachefiles_prepare_write()
  9p: Use netfslib read/write_iter
  afs: Use the netfs write helpers
  netfs: Export the netfs_sreq tracepoint
  netfs: Optimise away reads above the point at which there can be no data
  netfs: Implement a write-through caching option
  netfs: Provide a launder_folio implementation
  netfs: Provide a writepages implementation
  netfs, cachefiles: Pass upper bound length to allow expansion
  ...

3 files changed, 11 insertions, 63 deletions

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 13af429ab030..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)
@@ -509,7 +489,6 @@ static void ceph_netfs_free_request(struct netfs_io_request *rreq)
 const struct netfs_request_ops ceph_netfs_ops = {
 	.init_request		= ceph_init_request,
 	.free_request		= ceph_netfs_free_request,
-	.begin_cache_operation	= ceph_begin_cache_operation,
 	.issue_read		= ceph_netfs_issue_read,
 	.expand_readahead	= ceph_netfs_expand_readahead,
 	.clamp_length		= ceph_netfs_clamp_length,
@@ -1586,7 +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/ceph/cache.h b/fs/ceph/cache.h
index dc502daac49a..20efac020394 100644
--- a/fs/ceph/cache.h
+++ b/fs/ceph/cache.h
@@ -43,38 +43,19 @@ static inline void ceph_fscache_resize(struct inode *inode, loff_t to)
 	}
 }
 
-static inline void ceph_fscache_unpin_writeback(struct inode *inode,
+static inline int ceph_fscache_unpin_writeback(struct inode *inode,
 						struct writeback_control *wbc)
 {
-	fscache_unpin_writeback(wbc, ceph_fscache_cookie(ceph_inode(inode)));
+	return netfs_unpin_writeback(inode, wbc);
 }
 
-static inline int ceph_fscache_dirty_folio(struct address_space *mapping,
-		struct folio *folio)
-{
-	struct ceph_inode_info *ci = ceph_inode(mapping->host);
-
-	return fscache_dirty_folio(mapping, folio, ceph_fscache_cookie(ci));
-}
-
-static inline int ceph_begin_cache_operation(struct netfs_io_request *rreq)
-{
-	struct fscache_cookie *cookie = ceph_fscache_cookie(ceph_inode(rreq->inode));
-
-	return fscache_begin_read_operation(&rreq->cache_resources, cookie);
-}
+#define ceph_fscache_dirty_folio netfs_dirty_folio
 
 static inline bool ceph_is_cache_enabled(struct inode *inode)
 {
 	return fscache_cookie_enabled(ceph_fscache_cookie(ceph_inode(inode)));
 }
 
-static inline void ceph_fscache_note_page_release(struct inode *inode)
-{
-	struct ceph_inode_info *ci = ceph_inode(inode);
-
-	fscache_note_page_release(ceph_fscache_cookie(ci));
-}
 #else /* CONFIG_CEPH_FSCACHE */
 static inline int ceph_fscache_register_fs(struct ceph_fs_client* fsc,
 					   struct fs_context *fc)
@@ -119,30 +100,18 @@ static inline void ceph_fscache_resize(struct inode *inode, loff_t to)
 {
 }
 
-static inline void ceph_fscache_unpin_writeback(struct inode *inode,
-						struct writeback_control *wbc)
+static inline int ceph_fscache_unpin_writeback(struct inode *inode,
+					       struct writeback_control *wbc)
 {
+	return 0;
 }
 
-static inline int ceph_fscache_dirty_folio(struct address_space *mapping,
-		struct folio *folio)
-{
-	return filemap_dirty_folio(mapping, folio);
-}
+#define ceph_fscache_dirty_folio filemap_dirty_folio
 
 static inline bool ceph_is_cache_enabled(struct inode *inode)
 {
 	return false;
 }
-
-static inline int ceph_begin_cache_operation(struct netfs_io_request *rreq)
-{
-	return -ENOBUFS;
-}
-
-static inline void ceph_fscache_note_page_release(struct inode *inode)
-{
-}
 #endif /* CONFIG_CEPH_FSCACHE */
 
 #endif
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 0679240f06db..0c25d326afc4 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -574,7 +574,7 @@ struct inode *ceph_alloc_inode(struct super_block *sb)
 	doutc(fsc->client, "%p\n", &ci->netfs.inode);
 
 	/* Set parameters for the netfs library */
-	netfs_inode_init(&ci->netfs, &ceph_netfs_ops);
+	netfs_inode_init(&ci->netfs, &ceph_netfs_ops, false);
 
 	spin_lock_init(&ci->i_ceph_lock);
 
@@ -694,7 +694,7 @@ void ceph_evict_inode(struct inode *inode)
 	percpu_counter_dec(&mdsc->metric.total_inodes);
 
 	truncate_inode_pages_final(&inode->i_data);
-	if (inode->i_state & I_PINNING_FSCACHE_WB)
+	if (inode->i_state & I_PINNING_NETFS_WB)
 		ceph_fscache_unuse_cookie(inode, true);
 	clear_inode(inode);