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authorNick Piggin <npiggin@suse.de>2007-10-16 12:25:01 +0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-16 20:42:55 +0400
commitafddba49d18f346e5cc2938b6ed7c512db18ca68 (patch)
tree4726e3d3b0e9e8e5b5d3b2b0cccb36446bbdf3ca /fs/splice.c
parent637aff46f94a754207c80c8c64bf1b74f24b967d (diff)
downloadlinux-afddba49d18f346e5cc2938b6ed7c512db18ca68.tar.xz
fs: introduce write_begin, write_end, and perform_write aops
These are intended to replace prepare_write and commit_write with more flexible alternatives that are also able to avoid the buffered write deadlock problems efficiently (which prepare_write is unable to do). [mark.fasheh@oracle.com: API design contributions, code review and fixes] [akpm@linux-foundation.org: various fixes] [dmonakhov@sw.ru: new aop block_write_begin fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com> Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/splice.c')
-rw-r--r--fs/splice.c69
1 files changed, 7 insertions, 62 deletions
diff --git a/fs/splice.c b/fs/splice.c
index 2df6be43c667..a7568bcc0f99 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -563,7 +563,7 @@ static int pipe_to_file(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
struct address_space *mapping = file->f_mapping;
unsigned int offset, this_len;
struct page *page;
- pgoff_t index;
+ void *fsdata;
int ret;
/*
@@ -573,49 +573,16 @@ static int pipe_to_file(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
if (unlikely(ret))
return ret;
- index = sd->pos >> PAGE_CACHE_SHIFT;
offset = sd->pos & ~PAGE_CACHE_MASK;
this_len = sd->len;
if (this_len + offset > PAGE_CACHE_SIZE)
this_len = PAGE_CACHE_SIZE - offset;
-find_page:
- page = find_lock_page(mapping, index);
- if (!page) {
- ret = -ENOMEM;
- page = page_cache_alloc_cold(mapping);
- if (unlikely(!page))
- goto out_ret;
-
- /*
- * This will also lock the page
- */
- ret = add_to_page_cache_lru(page, mapping, index,
- GFP_KERNEL);
- if (unlikely(ret))
- goto out_release;
- }
-
- ret = mapping->a_ops->prepare_write(file, page, offset, offset+this_len);
- if (unlikely(ret)) {
- loff_t isize = i_size_read(mapping->host);
-
- if (ret != AOP_TRUNCATED_PAGE)
- unlock_page(page);
- page_cache_release(page);
- if (ret == AOP_TRUNCATED_PAGE)
- goto find_page;
-
- /*
- * prepare_write() may have instantiated a few blocks
- * outside i_size. Trim these off again.
- */
- if (sd->pos + this_len > isize)
- vmtruncate(mapping->host, isize);
-
- goto out_ret;
- }
+ ret = pagecache_write_begin(file, mapping, sd->pos, this_len,
+ AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);
+ if (unlikely(ret))
+ goto out;
if (buf->page != page) {
/*
@@ -629,31 +596,9 @@ find_page:
kunmap_atomic(dst, KM_USER1);
buf->ops->unmap(pipe, buf, src);
}
-
- ret = mapping->a_ops->commit_write(file, page, offset, offset+this_len);
- if (ret) {
- if (ret == AOP_TRUNCATED_PAGE) {
- page_cache_release(page);
- goto find_page;
- }
- if (ret < 0)
- goto out;
- /*
- * Partial write has happened, so 'ret' already initialized by
- * number of bytes written, Where is nothing we have to do here.
- */
- } else
- ret = this_len;
- /*
- * Return the number of bytes written and mark page as
- * accessed, we are now done!
- */
- mark_page_accessed(page);
+ ret = pagecache_write_end(file, mapping, sd->pos, this_len, this_len,
+ page, fsdata);
out:
- unlock_page(page);
-out_release:
- page_cache_release(page);
-out_ret:
return ret;
}