diff options
author | Joel Becker <joel.becker@oracle.com> | 2010-07-06 14:36:06 -0700 |
---|---|---|
committer | Joel Becker <joel.becker@oracle.com> | 2010-07-08 13:24:49 -0700 |
commit | a4bfb4cf11fd2211b788af59dc8a8b4394bca227 (patch) | |
tree | c06f45ac5a992575a0e47dbc80bdf187db030cca /fs/ocfs2/file.c | |
parent | 1739da40543ed2129050ccfa8a076a851ab6ed00 (diff) |
ocfs2: When zero extending, do it by page.
ocfs2_zero_extend() does its zeroing block by block, but it calls a
function named ocfs2_write_zero_page(). Let's have
ocfs2_write_zero_page() handle the page level. From
ocfs2_zero_extend()'s perspective, it is now page-at-a-time.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Cc: stable@kernel.org
Diffstat (limited to 'fs/ocfs2/file.c')
-rw-r--r-- | fs/ocfs2/file.c | 118 |
1 files changed, 84 insertions, 34 deletions
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 6a13ea64c44..4cfc976a906 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -724,28 +724,55 @@ leave: return status; } +/* + * While a write will already be ordering the data, a truncate will not. + * Thus, we need to explicitly order the zeroed pages. + */ +static handle_t *ocfs2_zero_start_ordered_transaction(struct inode *inode) +{ + struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); + handle_t *handle = NULL; + int ret = 0; + + if (!ocfs2_should_order_data(inode)) + goto out; + + handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS); + if (IS_ERR(handle)) { + ret = -ENOMEM; + mlog_errno(ret); + goto out; + } + + ret = ocfs2_jbd2_file_inode(handle, inode); + if (ret < 0) + mlog_errno(ret); + +out: + if (ret) { + if (!IS_ERR(handle)) + ocfs2_commit_trans(osb, handle); + handle = ERR_PTR(ret); + } + return handle; +} + /* Some parts of this taken from generic_cont_expand, which turned out * to be too fragile to do exactly what we need without us having to * worry about recursive locking in ->write_begin() and ->write_end(). */ -static int ocfs2_write_zero_page(struct inode *inode, - u64 size) +static int ocfs2_write_zero_page(struct inode *inode, u64 abs_from, + u64 abs_to) { struct address_space *mapping = inode->i_mapping; struct page *page; - unsigned long index; - unsigned int offset; + unsigned long index = abs_from >> PAGE_CACHE_SHIFT; handle_t *handle = NULL; int ret; + unsigned zero_from, zero_to, block_start, block_end; - offset = (size & (PAGE_CACHE_SIZE-1)); /* Within page */ - /* ugh. in prepare/commit_write, if from==to==start of block, we - ** skip the prepare. make sure we never send an offset for the start - ** of a block - */ - if ((offset & (inode->i_sb->s_blocksize - 1)) == 0) { - offset++; - } - index = size >> PAGE_CACHE_SHIFT; + BUG_ON(abs_from >= abs_to); + BUG_ON(abs_to > (((u64)index + 1) << PAGE_CACHE_SHIFT)); + BUG_ON(abs_from & (inode->i_blkbits - 1)); page = grab_cache_page(mapping, index); if (!page) { @@ -754,31 +781,51 @@ static int ocfs2_write_zero_page(struct inode *inode, goto out; } - ret = ocfs2_prepare_write_nolock(inode, page, offset, offset); - if (ret < 0) { - mlog_errno(ret); - goto out_unlock; - } + /* Get the offsets within the page that we want to zero */ + zero_from = abs_from & (PAGE_CACHE_SIZE - 1); + zero_to = abs_to & (PAGE_CACHE_SIZE - 1); + if (!zero_to) + zero_to = PAGE_CACHE_SIZE; - if (ocfs2_should_order_data(inode)) { - handle = ocfs2_start_walk_page_trans(inode, page, offset, - offset); - if (IS_ERR(handle)) { - ret = PTR_ERR(handle); - handle = NULL; + /* We know that zero_from is block aligned */ + for (block_start = zero_from; block_start < zero_to; + block_start = block_end) { + block_end = block_start + (1 << inode->i_blkbits); + + /* + * block_start is block-aligned. Bump it by one to + * force ocfs2_{prepare,commit}_write() to zero the + * whole block. + */ + ret = ocfs2_prepare_write_nolock(inode, page, + block_start + 1, + block_start + 1); + if (ret < 0) { + mlog_errno(ret); goto out_unlock; } - } - /* must not update i_size! */ - ret = block_commit_write(page, offset, offset); - if (ret < 0) - mlog_errno(ret); - else - ret = 0; + if (!handle) { + handle = ocfs2_zero_start_ordered_transaction(inode); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + handle = NULL; + break; + } + } + + /* must not update i_size! */ + ret = block_commit_write(page, block_start + 1, + block_start + 1); + if (ret < 0) + mlog_errno(ret); + else + ret = 0; + } if (handle) ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle); + out_unlock: unlock_page(page); page_cache_release(page); @@ -790,18 +837,21 @@ static int ocfs2_zero_extend(struct inode *inode, u64 zero_to_size) { int ret = 0; - u64 start_off; + u64 start_off, next_off; struct super_block *sb = inode->i_sb; start_off = ocfs2_align_bytes_to_blocks(sb, i_size_read(inode)); while (start_off < zero_to_size) { - ret = ocfs2_write_zero_page(inode, start_off); + next_off = (start_off & PAGE_CACHE_MASK) + PAGE_CACHE_SIZE; + if (next_off > zero_to_size) + next_off = zero_to_size; + ret = ocfs2_write_zero_page(inode, start_off, next_off); if (ret < 0) { mlog_errno(ret); goto out; } - start_off += sb->s_blocksize; + start_off = next_off; /* * Very large extends have the potential to lock up |