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author | Nick Piggin <npiggin@suse.de> | 2007-10-16 01:25:01 -0700 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-16 09:42:55 -0700 |
commit | afddba49d18f346e5cc2938b6ed7c512db18ca68 (patch) | |
tree | 4726e3d3b0e9e8e5b5d3b2b0cccb36446bbdf3ca /fs/splice.c | |
parent | 637aff46f94a754207c80c8c64bf1b74f24b967d (diff) | |
download | kernel_samsung_smdk4412-afddba49d18f346e5cc2938b6ed7c512db18ca68.zip kernel_samsung_smdk4412-afddba49d18f346e5cc2938b6ed7c512db18ca68.tar.gz kernel_samsung_smdk4412-afddba49d18f346e5cc2938b6ed7c512db18ca68.tar.bz2 |
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.c | 69 |
1 files changed, 7 insertions, 62 deletions
diff --git a/fs/splice.c b/fs/splice.c index 2df6be4..a7568bc 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; } |