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linux-kernel: [PATCH 21/37] NFS: Add comment banners to some NFS

[PATCH 21/37] NFS: Add comment banners to some NFS functions

From: David Howells <dhowells_at_nospam>
Date: Fri Feb 08 2008 - 16:53:50 GMT
To: Trond.Myklebust@netapp.com, chuck.lever@oracle.com


Add comment banners to some NFS functions so that they can be modified by the NFS fscache patches for further information.

Signed-off-by: David Howells <dhowells@redhat.com> --- fs/nfs/file.c | 26 ++++++++++++++++++++++++++ 1 files changed, 26 insertions(+), 0 deletions(-) diff --git a/fs/nfs/file.c b/fs/nfs/file.c index ef57a5a..26a073b 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -354,6 +354,13 @@ static int nfs_write_end(struct file *file, struct address_space *mapping, return copied; } +/*
+ * 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
+ * - Caller holds page lock
+ */ static void nfs_invalidate_page(struct page *page, unsigned long offset) { if (offset != 0) @@ -362,12 +369,26 @@ static void nfs_invalidate_page(struct page *page, unsigned long offset) nfs_wb_page_cancel(page->mapping->host, page); } +/*
+ * Attempt to release the private state associated with a page
+ * - Called if either PG_private or PG_private_2 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; } +/*
+ * 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
+ * - Caller holds page lock
+ * - Return 0 if successful, -error otherwise
+ */ static int nfs_launder_page(struct page *page) { return nfs_wb_page(page->mapping->host, page); @@ -389,6 +410,11 @@ const struct address_space_operations nfs_file_aops = { .launder_page = nfs_launder_page, }; +/*
+ * Notification that a PTE pointing to an NFS page is about to be made
+ * writable, implying that someone is about to modify the page through a
+ * shared-writable mapping
+ */ static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page) { struct file *filp = vma->vm_file; - To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html