fs: affs convert to new aops
Nick Piggin [Tue, 16 Oct 2007 08:25:24 +0000 (01:25 -0700)]
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/affs/file.c

index c314a35..6e0c939 100644 (file)
@@ -395,25 +395,33 @@ static int affs_writepage(struct page *page, struct writeback_control *wbc)
 {
        return block_write_full_page(page, affs_get_block, wbc);
 }
+
 static int affs_readpage(struct file *file, struct page *page)
 {
        return block_read_full_page(page, affs_get_block);
 }
-static int affs_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
+
+static int affs_write_begin(struct file *file, struct address_space *mapping,
+                       loff_t pos, unsigned len, unsigned flags,
+                       struct page **pagep, void **fsdata)
 {
-       return cont_prepare_write(page, from, to, affs_get_block,
-               &AFFS_I(page->mapping->host)->mmu_private);
+       *pagep = NULL;
+       return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+                               affs_get_block,
+                               &AFFS_I(mapping->host)->mmu_private);
 }
+
 static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
 {
        return generic_block_bmap(mapping,block,affs_get_block);
 }
+
 const struct address_space_operations affs_aops = {
        .readpage = affs_readpage,
        .writepage = affs_writepage,
        .sync_page = block_sync_page,
-       .prepare_write = affs_prepare_write,
-       .commit_write = generic_commit_write,
+       .write_begin = affs_write_begin,
+       .write_end = generic_write_end,
        .bmap = _affs_bmap
 };
 
@@ -603,54 +611,65 @@ affs_readpage_ofs(struct file *file, struct page *page)
        return err;
 }
 
-static int affs_prepare_write_ofs(struct file *file, struct page *page, unsigned from, unsigned to)
+static int affs_write_begin_ofs(struct file *file, struct address_space *mapping,
+                               loff_t pos, unsigned len, unsigned flags,
+                               struct page **pagep, void **fsdata)
 {
-       struct inode *inode = page->mapping->host;
-       u32 size, offset;
-       u32 tmp;
+       struct inode *inode = mapping->host;
+       struct page *page;
+       pgoff_t index;
        int err = 0;
 
-       pr_debug("AFFS: prepare_write(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to);
-       offset = page->index << PAGE_CACHE_SHIFT;
-       if (offset + from > AFFS_I(inode)->mmu_private) {
-               err = affs_extent_file_ofs(inode, offset + from);
+       pr_debug("AFFS: write_begin(%u, %llu, %llu)\n", (u32)inode->i_ino, (unsigned long long)pos, (unsigned long long)pos + len);
+       if (pos > AFFS_I(inode)->mmu_private) {
+               /* XXX: this probably leaves a too-big i_size in case of
+                * failure. Should really be updating i_size at write_end time
+                */
+               err = affs_extent_file_ofs(inode, pos);
                if (err)
                        return err;
        }
-       size = inode->i_size;
+
+       index = pos >> PAGE_CACHE_SHIFT;
+       page = __grab_cache_page(mapping, index);
+       if (!page)
+               return -ENOMEM;
+       *pagep = page;
 
        if (PageUptodate(page))
                return 0;
 
-       if (from) {
-               err = affs_do_readpage_ofs(file, page, 0, from);
-               if (err)
-                       return err;
-       }
-       if (to < PAGE_CACHE_SIZE) {
-               zero_user_page(page, to, PAGE_CACHE_SIZE - to, KM_USER0);
-               if (size > offset + to) {
-                       if (size < offset + PAGE_CACHE_SIZE)
-                               tmp = size & ~PAGE_CACHE_MASK;
-                       else
-                               tmp = PAGE_CACHE_SIZE;
-                       err = affs_do_readpage_ofs(file, page, to, tmp);
-               }
+       /* XXX: inefficient but safe in the face of short writes */
+       err = affs_do_readpage_ofs(file, page, 0, PAGE_CACHE_SIZE);
+       if (err) {
+               unlock_page(page);
+               page_cache_release(page);
        }
        return err;
 }
 
-static int affs_commit_write_ofs(struct file *file, struct page *page, unsigned from, unsigned to)
+static int affs_write_end_ofs(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;
+       struct inode *inode = mapping->host;
        struct super_block *sb = inode->i_sb;
        struct buffer_head *bh, *prev_bh;
        char *data;
        u32 bidx, boff, bsize;
+       unsigned from, to;
        u32 tmp;
        int written;
 
-       pr_debug("AFFS: commit_write(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to);
+       from = pos & (PAGE_CACHE_SIZE - 1);
+       to = pos + len;
+       /*
+        * XXX: not sure if this can handle short copies (len < copied), but
+        * we don't have to, because the page should always be uptodate here,
+        * due to write_begin.
+        */
+
+       pr_debug("AFFS: write_begin(%u, %llu, %llu)\n", (u32)inode->i_ino, (unsigned long long)pos, (unsigned long long)pos + len);
        bsize = AFFS_SB(sb)->s_data_blksize;
        data = page_address(page);
 
@@ -748,6 +767,9 @@ done:
        if (tmp > inode->i_size)
                inode->i_size = AFFS_I(inode)->mmu_private = tmp;
 
+       unlock_page(page);
+       page_cache_release(page);
+
        return written;
 
 out:
@@ -761,8 +783,8 @@ const struct address_space_operations affs_aops_ofs = {
        .readpage = affs_readpage_ofs,
        //.writepage = affs_writepage_ofs,
        //.sync_page = affs_sync_page_ofs,
-       .prepare_write = affs_prepare_write_ofs,
-       .commit_write = affs_commit_write_ofs
+       .write_begin = affs_write_begin_ofs,
+       .write_end = affs_write_end_ofs
 };
 
 /* Free any preallocated blocks. */
@@ -805,18 +827,13 @@ affs_truncate(struct inode *inode)
        if (inode->i_size > AFFS_I(inode)->mmu_private) {
                struct address_space *mapping = inode->i_mapping;
                struct page *page;
-               u32 size = inode->i_size - 1;
+               void *fsdata;
+               u32 size = inode->i_size;
                int res;
 
-               page = grab_cache_page(mapping, size >> PAGE_CACHE_SHIFT);
-               if (!page)
-                       return;
-               size = (size & (PAGE_CACHE_SIZE - 1)) + 1;
-               res = mapping->a_ops->prepare_write(NULL, page, size, size);
+               res = mapping->a_ops->write_begin(NULL, mapping, size, 0, 0, &page, &fsdata);
                if (!res)
-                       res = mapping->a_ops->commit_write(NULL, page, size, size);
-               unlock_page(page);
-               page_cache_release(page);
+                       res = mapping->a_ops->write_end(NULL, mapping, size, 0, 0, page, fsdata);
                mark_inode_dirty(inode);
                return;
        } else if (inode->i_size == AFFS_I(inode)->mmu_private)