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 <dhowells@xxxxxxxxxx> Acked-by: Steve Dickson <steved@xxxxxxxxxx> Acked-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx> Acked-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Tested-by: Daire Byrne <Daire.Byrne@xxxxxxxxxxxxxx> --- fs/nfs/file.c | 18 ++++++++++++++---- fs/nfs/fscache.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/nfs/fscache.h | 34 ++++++++++++++++++++++++++++++++++ 3 files changed, 101 insertions(+), 4 deletions(-) diff --git a/fs/nfs/file.c b/fs/nfs/file.c index f5bc54d..3523b89 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_FACILITY NFSDBG_FILE @@ -413,7 +414,7 @@ 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) @@ -424,11 +425,13 @@ 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) */ @@ -437,24 +440,28 @@ static int nfs_release_page(struct page *page, gfp_t gfp) dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page); /* 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) { struct inode *inode = page->mapping->host; + struct nfs_inode *nfsi = NFS_I(inode); dfprintk(PAGECACHE, "NFS: launder_page(%ld, %llu)\n", inode->i_ino, (long long)page_offset(page)); + nfs_fscache_wait_on_page_write(nfsi, page); return nfs_wb_page(inode, page); } @@ -491,6 +498,9 @@ static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) filp->f_mapping->host->i_ino, (long long)page_offset(page)); + /* make sure the cache has finished storing the page */ + nfs_fscache_wait_on_page_write(NFS_I(dentry->d_inode), page); + lock_page(page); mapping = page->mapping; if (mapping != dentry->d_inode->i_mapping) diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c index e3816eb..f673d35 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_FACILITY NFSDBG_FSCACHE @@ -328,3 +329,55 @@ void nfs_fscache_reset_inode_cookie(struct inode *inode) } nfs_fscache_inode_unlock(inode); } + +/* + * 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) +{ + struct nfs_inode *nfsi = NFS_I(page->mapping->host); + struct fscache_cookie *cookie = nfsi->fscache; + + BUG_ON(!cookie); + + if (fscache_check_page_write(cookie, page)) { + if (!(gfp & __GFP_WAIT)) + return 0; + fscache_wait_on_page_write(cookie, page); + } + + if (PageFsCache(page)) { + dfprintk(FSCACHE, "NFS: fscache releasepage (0x%p/0x%p/0x%p)\n", + cookie, page, nfsi); + + fscache_uncache_page(cookie, page); + nfs_add_fscache_stats(page->mapping->host, + NFSIOS_FSCACHE_PAGES_UNCACHED, 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); + struct fscache_cookie *cookie = nfsi->fscache; + + BUG_ON(!cookie); + + dfprintk(FSCACHE, "NFS: fscache invalidatepage (0x%p/0x%p/0x%p)\n", + cookie, page, nfsi); + + fscache_wait_on_page_write(cookie, page); + + BUG_ON(!PageLocked(page)); + fscache_uncache_page(cookie, page); + nfs_add_fscache_stats(page->mapping->host, + NFSIOS_FSCACHE_PAGES_UNCACHED, 1); +} diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h index 8b4299a..e29613a 100644 --- a/fs/nfs/fscache.h +++ b/fs/nfs/fscache.h @@ -83,6 +83,31 @@ extern void nfs_fscache_zap_inode_cookie(struct inode *); extern void nfs_fscache_set_inode_cookie(struct inode *, struct file *); extern void nfs_fscache_reset_inode_cookie(struct inode *); +extern void __nfs_fscache_invalidate_page(struct page *, struct inode *); +extern int nfs_fscache_release_page(struct page *, gfp_t); + +/* + * wait for a page to complete writing to the cache + */ +static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi, + struct page *page) +{ + if (PageFsCache(page)) + fscache_wait_on_page_write(nfsi->fscache, page); +} + +/* + * release the caching state associated with a page if undergoing complete page + * invalidation + */ +static inline void nfs_fscache_invalidate_page(struct page *page, + struct inode *inode) +{ + if (PageFsCache(page)) + __nfs_fscache_invalidate_page(page, inode); +} + + #else /* CONFIG_NFS_FSCACHE */ static inline int nfs_fscache_register(void) { return 0; } static inline void nfs_fscache_unregister(void) {} @@ -104,5 +129,14 @@ static inline void nfs_fscache_set_inode_cookie(struct inode *inode, struct file *filp) {} static inline void nfs_fscache_reset_inode_cookie(struct inode *inode) {} +static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp) +{ + return 1; /* True: may release page */ +} +static inline void nfs_fscache_invalidate_page(struct page *page, + struct inode *inode) {} +static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi, + struct page *page) {} + #endif /* CONFIG_NFS_FSCACHE */ #endif /* _NFS_FSCACHE_H */ -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html