[PATCH 31/37] NFS: FS-Cache page management

2008-02-20 Thread David Howells
FS-Cache page management for NFS.  This includes hooking the releasing and
invalidation of pages marked with PG_fscache (aka PG_private_2) and waiting for
completion of the write-to-cache flag (PG_fscache_write aka PG_owner_priv_2).

Signed-off-by: David Howells [EMAIL PROTECTED]
---

 fs/nfs/file.c|   17 +
 fs/nfs/fscache.c |   49 +
 fs/nfs/fscache.h |   22 ++
 3 files changed, 84 insertions(+), 4 deletions(-)


diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 26a073b..60db3ea 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -35,6 +35,7 @@
 #include delegation.h
 #include internal.h
 #include iostat.h
+#include fscache.h
 
 #define NFSDBG_FACILITYNFSDBG_FILE
 
@@ -358,7 +359,7 @@ static int nfs_write_end(struct file *file, struct 
address_space *mapping,
  * Partially or wholly invalidate a page
  * - Release the private state associated with a page if undergoing complete
  *   page invalidation
- * - Called if either PG_private or PG_private_2 is set on the page
+ * - Called if either PG_private or PG_fscache is set on the page
  * - Caller holds page lock
  */
 static void nfs_invalidate_page(struct page *page, unsigned long offset)
@@ -367,30 +368,35 @@ static void nfs_invalidate_page(struct page *page, 
unsigned long offset)
return;
/* Cancel any unstarted writes on this page */
nfs_wb_page_cancel(page-mapping-host, page);
+
+   nfs_fscache_invalidate_page(page, page-mapping-host);
 }
 
 /*
  * Attempt to release the private state associated with a page
- * - Called if either PG_private or PG_private_2 is set on the page
+ * - Called if either PG_private or PG_fscache is set on the page
  * - Caller holds page lock
  * - Return true (may release page) or false (may not)
  */
 static int nfs_release_page(struct page *page, gfp_t gfp)
 {
/* If PagePrivate() is set, then the page is not freeable */
-   return 0;
+   if (PagePrivate(page))
+   return 0;
+   return nfs_fscache_release_page(page, gfp);
 }
 
 /*
  * Attempt to clear the private state associated with a page when an error
  * occurs that requires the cached contents of an inode to be written back or
  * destroyed
- * - Called if either PG_private or PG_private_2 is set on the page
+ * - Called if either PG_private or fscache is set on the page
  * - Caller holds page lock
  * - Return 0 if successful, -error otherwise
  */
 static int nfs_launder_page(struct page *page)
 {
+   wait_on_page_fscache_write(page);
return nfs_wb_page(page-mapping-host, page);
 }
 
@@ -422,6 +428,9 @@ static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, 
struct page *page)
int ret = -EINVAL;
struct address_space *mapping;
 
+   /* make sure the cache has finished storing the page */
+   wait_on_page_fscache_write(page);
+
lock_page(page);
mapping = page-mapping;
if (mapping != vma-vm_file-f_path.dentry-d_inode-i_mapping)
diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index c0e0320..d475ff5 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -19,6 +19,7 @@
 #include linux/seq_file.h
 
 #include internal.h
+#include iostat.h
 #include fscache.h
 
 #define NFSDBG_FACILITYNFSDBG_FSCACHE
@@ -297,3 +298,51 @@ void nfs_fscache_attr_changed(struct inode *inode)
 {
fscache_attr_changed(NFS_I(inode)-fscache);
 }
+
+/*
+ * Release the caching state associated with a page, if the page isn't busy
+ * interacting with the cache.
+ * - Returns true (can release page) or false (page busy).
+ */
+int nfs_fscache_release_page(struct page *page, gfp_t gfp)
+{
+   if (PageFsCacheWrite(page)) {
+   if (!(gfp  __GFP_WAIT))
+   return 0;
+   wait_on_page_fscache_write(page);
+   }
+
+   if (PageFsCache(page)) {
+   struct nfs_inode *nfsi = NFS_I(page-mapping-host);
+
+   BUG_ON(!nfsi-fscache);
+
+   dfprintk(FSCACHE, NFS: fscache releasepage (0x%p/0x%p/0x%p)\n,
+nfsi-fscache, page, nfsi);
+
+   fscache_uncache_page(nfsi-fscache, page);
+   nfs_add_stats(page-mapping-host, NFSIOS_FSCACHE_UNCACHE, 1);
+   }
+
+   return 1;
+}
+
+/*
+ * Release the caching state associated with a page if undergoing complete page
+ * invalidation.
+ */
+void __nfs_fscache_invalidate_page(struct page *page, struct inode *inode)
+{
+   struct nfs_inode *nfsi = NFS_I(inode);
+
+   BUG_ON(!nfsi-fscache);
+
+   dfprintk(FSCACHE, NFS: fscache invalidatepage (0x%p/0x%p/0x%p)\n,
+nfsi-fscache, page, nfsi);
+
+   wait_on_page_fscache_write(page);
+
+   BUG_ON(!PageLocked(page));
+   fscache_uncache_page(nfsi-fscache, page);
+   nfs_add_stats(page-mapping-host, NFSIOS_FSCACHE_UNCACHE, 1);
+}
diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h
index d730ec8..1cb7d96 

[PATCH 31/37] NFS: FS-Cache page management

2008-02-08 Thread David Howells
FS-Cache page management for NFS.  This includes hooking the releasing and
invalidation of pages marked with PG_fscache (aka PG_private_2) and waiting for
completion of the write-to-cache flag (PG_fscache_write aka PG_owner_priv_2).

Signed-off-by: David Howells [EMAIL PROTECTED]
---

 fs/nfs/file.c|   17 +
 fs/nfs/fscache.c |   49 +
 fs/nfs/fscache.h |   22 ++
 3 files changed, 84 insertions(+), 4 deletions(-)


diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 26a073b..60db3ea 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -35,6 +35,7 @@
 #include delegation.h
 #include internal.h
 #include iostat.h
+#include fscache.h
 
 #define NFSDBG_FACILITYNFSDBG_FILE
 
@@ -358,7 +359,7 @@ static int nfs_write_end(struct file *file, struct 
address_space *mapping,
  * Partially or wholly invalidate a page
  * - Release the private state associated with a page if undergoing complete
  *   page invalidation
- * - Called if either PG_private or PG_private_2 is set on the page
+ * - Called if either PG_private or PG_fscache is set on the page
  * - Caller holds page lock
  */
 static void nfs_invalidate_page(struct page *page, unsigned long offset)
@@ -367,30 +368,35 @@ static void nfs_invalidate_page(struct page *page, 
unsigned long offset)
return;
/* Cancel any unstarted writes on this page */
nfs_wb_page_cancel(page-mapping-host, page);
+
+   nfs_fscache_invalidate_page(page, page-mapping-host);
 }
 
 /*
  * Attempt to release the private state associated with a page
- * - Called if either PG_private or PG_private_2 is set on the page
+ * - Called if either PG_private or PG_fscache is set on the page
  * - Caller holds page lock
  * - Return true (may release page) or false (may not)
  */
 static int nfs_release_page(struct page *page, gfp_t gfp)
 {
/* If PagePrivate() is set, then the page is not freeable */
-   return 0;
+   if (PagePrivate(page))
+   return 0;
+   return nfs_fscache_release_page(page, gfp);
 }
 
 /*
  * Attempt to clear the private state associated with a page when an error
  * occurs that requires the cached contents of an inode to be written back or
  * destroyed
- * - Called if either PG_private or PG_private_2 is set on the page
+ * - Called if either PG_private or fscache is set on the page
  * - Caller holds page lock
  * - Return 0 if successful, -error otherwise
  */
 static int nfs_launder_page(struct page *page)
 {
+   wait_on_page_fscache_write(page);
return nfs_wb_page(page-mapping-host, page);
 }
 
@@ -422,6 +428,9 @@ static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, 
struct page *page)
int ret = -EINVAL;
struct address_space *mapping;
 
+   /* make sure the cache has finished storing the page */
+   wait_on_page_fscache_write(page);
+
lock_page(page);
mapping = page-mapping;
if (mapping != vma-vm_file-f_path.dentry-d_inode-i_mapping)
diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index c0e0320..d475ff5 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -19,6 +19,7 @@
 #include linux/seq_file.h
 
 #include internal.h
+#include iostat.h
 #include fscache.h
 
 #define NFSDBG_FACILITYNFSDBG_FSCACHE
@@ -297,3 +298,51 @@ void nfs_fscache_attr_changed(struct inode *inode)
 {
fscache_attr_changed(NFS_I(inode)-fscache);
 }
+
+/*
+ * Release the caching state associated with a page, if the page isn't busy
+ * interacting with the cache.
+ * - Returns true (can release page) or false (page busy).
+ */
+int nfs_fscache_release_page(struct page *page, gfp_t gfp)
+{
+   if (PageFsCacheWrite(page)) {
+   if (!(gfp  __GFP_WAIT))
+   return 0;
+   wait_on_page_fscache_write(page);
+   }
+
+   if (PageFsCache(page)) {
+   struct nfs_inode *nfsi = NFS_I(page-mapping-host);
+
+   BUG_ON(!nfsi-fscache);
+
+   dfprintk(FSCACHE, NFS: fscache releasepage (0x%p/0x%p/0x%p)\n,
+nfsi-fscache, page, nfsi);
+
+   fscache_uncache_page(nfsi-fscache, page);
+   nfs_add_stats(page-mapping-host, NFSIOS_FSCACHE_UNCACHE, 1);
+   }
+
+   return 1;
+}
+
+/*
+ * Release the caching state associated with a page if undergoing complete page
+ * invalidation.
+ */
+void __nfs_fscache_invalidate_page(struct page *page, struct inode *inode)
+{
+   struct nfs_inode *nfsi = NFS_I(inode);
+
+   BUG_ON(!nfsi-fscache);
+
+   dfprintk(FSCACHE, NFS: fscache invalidatepage (0x%p/0x%p/0x%p)\n,
+nfsi-fscache, page, nfsi);
+
+   wait_on_page_fscache_write(page);
+
+   BUG_ON(!PageLocked(page));
+   fscache_uncache_page(nfsi-fscache, page);
+   nfs_add_stats(page-mapping-host, NFSIOS_FSCACHE_UNCACHE, 1);
+}
diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h
index d730ec8..1cb7d96