[patch 14/41] implement simple fs aops

[npiggin@suse.de]

[-- Attachment #1: fs-simple-aops.patch --]
[-- Type: text/plain, Size: 6104 bytes --]

Implement new aops for some of the simpler filesystems.

Cc: Linux Filesystems <linux-fsdevel@vger.kernel.org>
Signed-off-by: Nick Piggin <npiggin@suse.de>

 fs/configfs/inode.c   |    4 ++--
 fs/hugetlbfs/inode.c  |   16 ++++++++++------
 fs/ramfs/file-mmu.c   |    4 ++--
 fs/ramfs/file-nommu.c |    4 ++--
 fs/sysfs/inode.c      |    4 ++--
 mm/shmem.c            |   35 ++++++++++++++++++++++++++++-------
 6 files changed, 46 insertions(+), 21 deletions(-)

Index: linux-2.6/mm/shmem.c
===================================================================
--- linux-2.6.orig/mm/shmem.c
+++ linux-2.6/mm/shmem.c
@@ -1107,7 +1107,7 @@ static int shmem_getpage(struct inode *i
 	 * Normally, filepage is NULL on entry, and either found
 	 * uptodate immediately, or allocated and zeroed, or read
 	 * in under swappage, which is then assigned to filepage.
-	 * But shmem_prepare_write passes in a locked filepage,
+	 * But shmem_write_begin passes in a locked filepage,
 	 * which may be found not uptodate by other callers too,
 	 * and may need to be copied from the swappage read in.
 	 */
@@ -1452,14 +1452,35 @@ static const struct inode_operations shm
 static const struct inode_operations shmem_symlink_inline_operations;
 
 /*
- * Normally tmpfs makes no use of shmem_prepare_write, but it
+ * Normally tmpfs makes no use of shmem_write_begin, but it
  * lets a tmpfs file be used read-write below the loop driver.
  */
 static int
-shmem_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
+shmem_write_begin(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned flags,
+			struct page **pagep, void **fsdata)
+{
+	struct inode *inode = mapping->host;
+	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+	*pagep = NULL;
+	return shmem_getpage(inode, index, pagep, SGP_WRITE, NULL);
+}
+
+static int
+shmem_write_end(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned copied,
+			struct page *page, void *fsdata)
 {
-	struct inode *inode = page->mapping->host;
-	return shmem_getpage(inode, page->index, &page, SGP_WRITE, NULL);
+	struct inode *inode = mapping->host;
+
+	set_page_dirty(page);
+	mark_page_accessed(page);
+	page_cache_release(page);
+
+	if (pos+copied > inode->i_size)
+		i_size_write(inode, pos+copied);
+
+	return copied;
 }
 
 static ssize_t
@@ -2353,8 +2374,8 @@ static const struct address_space_operat
 	.writepage	= shmem_writepage,
 	.set_page_dirty	= __set_page_dirty_no_writeback,
 #ifdef CONFIG_TMPFS
-	.prepare_write	= shmem_prepare_write,
-	.commit_write	= simple_commit_write,
+	.write_begin	= shmem_write_begin,
+	.write_end	= shmem_write_end,
 #endif
 	.migratepage	= migrate_page,
 };
Index: linux-2.6/fs/configfs/inode.c
===================================================================
--- linux-2.6.orig/fs/configfs/inode.c
+++ linux-2.6/fs/configfs/inode.c
@@ -41,8 +41,8 @@ extern struct super_block * configfs_sb;
 
 static const struct address_space_operations configfs_aops = {
 	.readpage	= simple_readpage,
-	.prepare_write	= simple_prepare_write,
-	.commit_write	= simple_commit_write
+	.write_begin	= simple_write_begin,
+	.write_end	= simple_write_end,
 };
 
 static struct backing_dev_info configfs_backing_dev_info = {
Index: linux-2.6/fs/sysfs/inode.c
===================================================================
--- linux-2.6.orig/fs/sysfs/inode.c
+++ linux-2.6/fs/sysfs/inode.c
@@ -21,8 +21,8 @@ extern struct super_block * sysfs_sb;
 
 static const struct address_space_operations sysfs_aops = {
 	.readpage	= simple_readpage,
-	.prepare_write	= simple_prepare_write,
-	.commit_write	= simple_commit_write
+	.write_begin	= simple_write_begin,
+	.write_end	= simple_write_end,
 };
 
 static struct backing_dev_info sysfs_backing_dev_info = {
Index: linux-2.6/fs/ramfs/file-mmu.c
===================================================================
--- linux-2.6.orig/fs/ramfs/file-mmu.c
+++ linux-2.6/fs/ramfs/file-mmu.c
@@ -29,8 +29,8 @@
 
 const struct address_space_operations ramfs_aops = {
 	.readpage	= simple_readpage,
-	.prepare_write	= simple_prepare_write,
-	.commit_write	= simple_commit_write,
+	.write_begin	= simple_write_begin,
+	.write_end	= simple_write_end,
 	.set_page_dirty = __set_page_dirty_no_writeback,
 };
 
Index: linux-2.6/fs/ramfs/file-nommu.c
===================================================================
--- linux-2.6.orig/fs/ramfs/file-nommu.c
+++ linux-2.6/fs/ramfs/file-nommu.c
@@ -29,8 +29,8 @@ static int ramfs_nommu_setattr(struct de
 
 const struct address_space_operations ramfs_aops = {
 	.readpage		= simple_readpage,
-	.prepare_write		= simple_prepare_write,
-	.commit_write		= simple_commit_write,
+	.write_begin		= simple_write_begin,
+	.write_end		= simple_write_end,
 	.set_page_dirty		= __set_page_dirty_no_writeback,
 };
 
Index: linux-2.6/fs/hugetlbfs/inode.c
===================================================================
--- linux-2.6.orig/fs/hugetlbfs/inode.c
+++ linux-2.6/fs/hugetlbfs/inode.c
@@ -166,15 +166,19 @@ static int hugetlbfs_readpage(struct fil
 	return -EINVAL;
 }
 
-static int hugetlbfs_prepare_write(struct file *file,
-			struct page *page, unsigned offset, unsigned to)
+static int hugetlbfs_write_begin(struct file *file,
+			struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned flags,
+			struct page **pagep, void **fsdata)
 {
 	return -EINVAL;
 }
 
-static int hugetlbfs_commit_write(struct file *file,
-			struct page *page, unsigned offset, unsigned to)
+static int hugetlbfs_write_end(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned copied,
+			struct page *page, void *fsdata)
 {
+	BUG();
 	return -EINVAL;
 }
 
@@ -546,8 +550,8 @@ static void hugetlbfs_destroy_inode(stru
 
 static const struct address_space_operations hugetlbfs_aops = {
 	.readpage	= hugetlbfs_readpage,
-	.prepare_write	= hugetlbfs_prepare_write,
-	.commit_write	= hugetlbfs_commit_write,
+	.write_begin	= hugetlbfs_write_begin,
+	.write_end	= hugetlbfs_write_end,
 	.set_page_dirty	= hugetlbfs_set_page_dirty,
 };
 

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