Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client

Pull Ceph fixes from Sage Weil:
 "We have a few follow-up fixes for the libceph refactor from Ilya, and
  then some cephfs + fscache fixes from Zheng.

  The first two FS-Cache patches are acked by David Howells and deemed
  trivial enough to go through our tree.  The rest fix some issues with
  the ceph fscache handling (disable cache for inodes opened for write,
  and simplify the revalidation logic accordingly, dropping the
  now-unnecessary work queue)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  ceph: use i_version to check validity of fscache
  ceph: improve fscache revalidation
  ceph: disable fscache when inode is opened for write
  ceph: avoid unnecessary fscache invalidation/revlidation
  ceph: call __fscache_uncache_page() if readpages fails
  FS-Cache: make check_consistency callback return int
  FS-Cache: wake write waiter after invalidating writes
  libceph: use %s instead of %pE in dout()s
  libceph: put request only if it's done in handle_reply()
  libceph: change ceph_osdmap_flag() to take osdc

Author: torvalds

fs/cachefiles/interface.c

@@ -380,7 +380,7 @@ static void cachefiles_sync_cache(struct fscache_cache *_cache)
  * check if the backing cache is updated to FS-Cache
  * - called by FS-Cache when evaluates if need to invalidate the cache
  */
-static bool cachefiles_check_consistency(struct fscache_operation *op)
+static int cachefiles_check_consistency(struct fscache_operation *op)
 {
 	struct cachefiles_object *object;
 	struct cachefiles_cache *cache;

fs/ceph/addr.c

@@ -276,8 +276,10 @@ static void finish_read(struct ceph_osd_request *req)
 	for (i = 0; i < num_pages; i++) {
 		struct page *page = osd_data->pages[i];
 
-		if (rc < 0 && rc != -ENOENT)
+		if (rc < 0 && rc != -ENOENT) {
+			ceph_fscache_readpage_cancel(inode, page);
 			goto unlock;
+		}
 		if (bytes < (int)PAGE_SIZE) {
 			/* zero (remainder of) page */
 			int s = bytes < 0 ? 0 : bytes;
@@ -535,8 +537,6 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
 	    CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb))
 		set_bdi_congested(&fsc->backing_dev_info, BLK_RW_ASYNC);
 
-	ceph_readpage_to_fscache(inode, page);
-
 	set_page_writeback(page);
 	err = ceph_osdc_writepages(osdc, ceph_vino(inode),
 				   &ci->i_layout, snapc,

fs/ceph/cache.c

@@ -25,6 +25,7 @@
 #include "cache.h"
 
 struct ceph_aux_inode {
+	u64 		version;
 	struct timespec	mtime;
 	loff_t          size;
 };
@@ -69,15 +70,8 @@ int ceph_fscache_register_fs(struct ceph_fs_client* fsc)
 	fsc->fscache = fscache_acquire_cookie(ceph_cache_netfs.primary_index,
 					      &ceph_fscache_fsid_object_def,
 					      fsc, true);
-
-	if (fsc->fscache == NULL) {
+	if (!fsc->fscache)
 		pr_err("Unable to resgister fsid: %p fscache cookie", fsc);
-		return 0;
-	}
-
-	fsc->revalidate_wq = alloc_workqueue("ceph-revalidate", 0, 1);
-	if (fsc->revalidate_wq == NULL)
-		return -ENOMEM;
 
 	return 0;
 }
@@ -105,6 +99,7 @@ static uint16_t ceph_fscache_inode_get_aux(const void *cookie_netfs_data,
 	const struct inode* inode = &ci->vfs_inode;
 
 	memset(&aux, 0, sizeof(aux));
+	aux.version = ci->i_version;
 	aux.mtime = inode->i_mtime;
 	aux.size = i_size_read(inode);
 
@@ -131,6 +126,7 @@ static enum fscache_checkaux ceph_fscache_inode_check_aux(
 		return FSCACHE_CHECKAUX_OBSOLETE;
 
 	memset(&aux, 0, sizeof(aux));
+	aux.version = ci->i_version;
 	aux.mtime = inode->i_mtime;
 	aux.size = i_size_read(inode);
 
@@ -181,32 +177,26 @@ static const struct fscache_cookie_def ceph_fscache_inode_object_def = {
 	.now_uncached	= ceph_fscache_inode_now_uncached,
 };
 
-void ceph_fscache_register_inode_cookie(struct ceph_fs_client* fsc,
-					struct ceph_inode_info* ci)
+void ceph_fscache_register_inode_cookie(struct inode *inode)
 {
-	struct inode* inode = &ci->vfs_inode;
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 
 	/* No caching for filesystem */
 	if (fsc->fscache == NULL)
 		return;
 
 	/* Only cache for regular files that are read only */
-	if ((ci->vfs_inode.i_mode & S_IFREG) == 0)
+	if (!S_ISREG(inode->i_mode))
 		return;
 
-	/* Avoid multiple racing open requests */
-	inode_lock(inode);
-
-	if (ci->fscache)
-		goto done;
-
-	ci->fscache = fscache_acquire_cookie(fsc->fscache,
-					     &ceph_fscache_inode_object_def,
-					     ci, true);
-	fscache_check_consistency(ci->fscache);
-done:
+	inode_lock_nested(inode, I_MUTEX_CHILD);
+	if (!ci->fscache) {
+		ci->fscache = fscache_acquire_cookie(fsc->fscache,
+					&ceph_fscache_inode_object_def,
+					ci, false);
+	}
 	inode_unlock(inode);
-
 }
 
 void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
@@ -222,6 +212,34 @@ void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
 	fscache_relinquish_cookie(cookie, 0);
 }
 
+static bool ceph_fscache_can_enable(void *data)
+{
+	struct inode *inode = data;
+	return !inode_is_open_for_write(inode);
+}
+
+void ceph_fscache_file_set_cookie(struct inode *inode, struct file *filp)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+
+	if (!fscache_cookie_valid(ci->fscache))
+		return;
+
+	if (inode_is_open_for_write(inode)) {
+		dout("fscache_file_set_cookie %p %p disabling cache\n",
+		     inode, filp);
+		fscache_disable_cookie(ci->fscache, false);
+		fscache_uncache_all_inode_pages(ci->fscache, inode);
+	} else {
+		fscache_enable_cookie(ci->fscache, ceph_fscache_can_enable,
+				inode);
+		if (fscache_cookie_enabled(ci->fscache)) {
+			dout("fscache_file_set_cookie %p %p enabing cache\n",
+			     inode, filp);
+		}
+	}
+}
+
 static void ceph_vfs_readpage_complete(struct page *page, void *data, int error)
 {
 	if (!error)
@@ -238,8 +256,7 @@ static void ceph_vfs_readpage_complete_unlock(struct page *page, void *data, int
 
 static inline bool cache_valid(struct ceph_inode_info *ci)
 {
-	return ((ceph_caps_issued(ci) & CEPH_CAP_FILE_CACHE) &&
-		(ci->i_fscache_gen == ci->i_rdcache_gen));
+	return ci->i_fscache_gen == ci->i_rdcache_gen;
 }
 
 
@@ -332,69 +349,27 @@ void ceph_invalidate_fscache_page(struct inode* inode, struct page *page)
 
 void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc)
 {
-	if (fsc->revalidate_wq)
-		destroy_workqueue(fsc->revalidate_wq);
-
 	fscache_relinquish_cookie(fsc->fscache, 0);
 	fsc->fscache = NULL;
 }
 
-static void ceph_revalidate_work(struct work_struct *work)
-{
-	int issued;
-	u32 orig_gen;
-	struct ceph_inode_info *ci = container_of(work, struct ceph_inode_info,
-						  i_revalidate_work);
-	struct inode *inode = &ci->vfs_inode;
-
-	spin_lock(&ci->i_ceph_lock);
-	issued = __ceph_caps_issued(ci, NULL);
-	orig_gen = ci->i_rdcache_gen;
-	spin_unlock(&ci->i_ceph_lock);
-
-	if (!(issued & CEPH_CAP_FILE_CACHE)) {
-		dout("revalidate_work lost cache before validation %p\n",
-		     inode);
-		goto out;
-	}
-
-	if (!fscache_check_consistency(ci->fscache))
-		fscache_invalidate(ci->fscache);
-
-	spin_lock(&ci->i_ceph_lock);
-	/* Update the new valid generation (backwards sanity check too) */
-	if (orig_gen > ci->i_fscache_gen) {
-		ci->i_fscache_gen = orig_gen;
-	}
-	spin_unlock(&ci->i_ceph_lock);
-
-out:
-	iput(&ci->vfs_inode);
-}
-
-void ceph_queue_revalidate(struct inode *inode)
+/*
+ * caller should hold CEPH_CAP_FILE_{RD,CACHE}
+ */
+void ceph_fscache_revalidate_cookie(struct ceph_inode_info *ci)
 {
-	struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb);
-	struct ceph_inode_info *ci = ceph_inode(inode);
-
-	if (fsc->revalidate_wq == NULL || ci->fscache == NULL)
+	if (cache_valid(ci))
 		return;
 
-	ihold(inode);
-
-	if (queue_work(ceph_sb_to_client(inode->i_sb)->revalidate_wq,
-		       &ci->i_revalidate_work)) {
-		dout("ceph_queue_revalidate %p\n", inode);
-	} else {
-		dout("ceph_queue_revalidate %p failed\n)", inode);
-		iput(inode);
+	/* resue i_truncate_mutex. There should be no pending
+	 * truncate while the caller holds CEPH_CAP_FILE_RD */
+	mutex_lock(&ci->i_truncate_mutex);
+	if (!cache_valid(ci)) {
+		if (fscache_check_consistency(ci->fscache))
+			fscache_invalidate(ci->fscache);
+		spin_lock(&ci->i_ceph_lock);
+		ci->i_fscache_gen = ci->i_rdcache_gen;
+		spin_unlock(&ci->i_ceph_lock);
 	}
-}
-
-void ceph_fscache_inode_init(struct ceph_inode_info *ci)
-{
-	ci->fscache = NULL;
-	/* The first load is verifed cookie open time */
-	ci->i_fscache_gen = 1;
-	INIT_WORK(&ci->i_revalidate_work, ceph_revalidate_work);
+	mutex_unlock(&ci->i_truncate_mutex);
 }

fs/ceph/cache.h

@@ -34,10 +34,10 @@ void ceph_fscache_unregister(void);
 int ceph_fscache_register_fs(struct ceph_fs_client* fsc);
 void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc);
 
-void ceph_fscache_inode_init(struct ceph_inode_info *ci);
-void ceph_fscache_register_inode_cookie(struct ceph_fs_client* fsc,
-					struct ceph_inode_info* ci);
+void ceph_fscache_register_inode_cookie(struct inode *inode);
 void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci);
+void ceph_fscache_file_set_cookie(struct inode *inode, struct file *filp);
+void ceph_fscache_revalidate_cookie(struct ceph_inode_info *ci);
 
 int ceph_readpage_from_fscache(struct inode *inode, struct page *page);
 int ceph_readpages_from_fscache(struct inode *inode,
@@ -46,12 +46,11 @@ int ceph_readpages_from_fscache(struct inode *inode,
 				unsigned *nr_pages);
 void ceph_readpage_to_fscache(struct inode *inode, struct page *page);
 void ceph_invalidate_fscache_page(struct inode* inode, struct page *page);
-void ceph_queue_revalidate(struct inode *inode);
 
-static inline void ceph_fscache_update_objectsize(struct inode *inode)
+static inline void ceph_fscache_inode_init(struct ceph_inode_info *ci)
 {
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	fscache_attr_changed(ci->fscache);
+	ci->fscache = NULL;
+	ci->i_fscache_gen = 0;
 }
 
 static inline void ceph_fscache_invalidate(struct inode *inode)
@@ -88,6 +87,11 @@ static inline void ceph_fscache_readpages_cancel(struct inode *inode,
 	return fscache_readpages_cancel(ci->fscache, pages);
 }
 
+static inline void ceph_disable_fscache_readpage(struct ceph_inode_info *ci)
+{
+	ci->i_fscache_gen = ci->i_rdcache_gen - 1;
+}
+
 #else
 
 static inline int ceph_fscache_register(void)
@@ -112,8 +116,20 @@ static inline void ceph_fscache_inode_init(struct ceph_inode_info *ci)
 {
 }
 
-static inline void ceph_fscache_register_inode_cookie(struct ceph_fs_client* parent_fsc,
-						      struct ceph_inode_info* ci)
+static inline void ceph_fscache_register_inode_cookie(struct inode *inode)
+{
+}
+
+static inline void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
+{
+}
+
+static inline void ceph_fscache_file_set_cookie(struct inode *inode,
+						struct file *filp)
+{
+}
+
+static inline void ceph_fscache_revalidate_cookie(struct ceph_inode_info *ci)
 {
 }
 
@@ -141,10 +157,6 @@ static inline void ceph_readpage_to_fscache(struct inode *inode,
 {
 }
 
-static inline void ceph_fscache_update_objectsize(struct inode *inode)
-{
-}
-
 static inline void ceph_fscache_invalidate(struct inode *inode)
 {
 }
@@ -154,10 +166,6 @@ static inline void ceph_invalidate_fscache_page(struct inode *inode,
 {
 }
 
-static inline void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
-{
-}
-
 static inline int ceph_release_fscache_page(struct page *page, gfp_t gfp)
 {
 	return 1;
@@ -173,7 +181,7 @@ static inline void ceph_fscache_readpages_cancel(struct inode *inode,
 {
 }
 
-static inline void ceph_queue_revalidate(struct inode *inode)
+static inline void ceph_disable_fscache_readpage(struct ceph_inode_info *ci)
 {
 }