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f2fs: revisit inline_data to avoid data races and potential bugs

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This patch simplifies the inline_data usage with the following rule.
1. inline_data is set during the file creation.
2. If new data is requested to be written ranges out of inline_data,
 f2fs converts that inode permanently.
3. There is no cases which converts non-inline_data inode to inline_data.
4. The inline_data flag should be changed under inode page lock.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Jaegeuk Kim
2014-10-23 19:48:09 -07:00
parent 1f7732fe6c
commit b3d208f96d
7 changed files with 252 additions and 213 deletions
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91
fs/f2fs/data.c
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@@ -737,14 +737,14 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
static int f2fs_read_data_page(struct file *file, struct page *page)
{
struct inode *inode = page->mapping->host;
int ret;
int ret = -EAGAIN;
trace_f2fs_readpage(page, DATA);
/* If the file has inline data, try to read it directly */
if (f2fs_has_inline_data(inode))
ret = f2fs_read_inline_data(inode, page);
else
if (ret == -EAGAIN)
ret = mpage_readpage(page, get_data_block);
return ret;
@@ -856,10 +856,11 @@ write:
else if (has_not_enough_free_secs(sbi, 0))
goto redirty_out;
err = -EAGAIN;
f2fs_lock_op(sbi);
if (f2fs_has_inline_data(inode) || f2fs_may_inline(inode))
err = f2fs_write_inline_data(inode, page, offset);
else
if (f2fs_has_inline_data(inode))
err = f2fs_write_inline_data(inode, page);
if (err == -EAGAIN)
err = do_write_data_page(page, &fio);
f2fs_unlock_op(sbi);
done:
@@ -957,24 +958,14 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping,
f2fs_balance_fs(sbi);
repeat:
err = f2fs_convert_inline_data(inode, pos + len, NULL);
if (err)
goto fail;
page = grab_cache_page_write_begin(mapping, index, flags);
if (!page) {
err = -ENOMEM;
goto fail;
}
/* to avoid latency during memory pressure */
unlock_page(page);
*pagep = page;
if (f2fs_has_inline_data(inode) && (pos + len) <= MAX_INLINE_DATA)
goto inline_data;
f2fs_lock_op(sbi);
/* check inline_data */
@@ -982,32 +973,42 @@ repeat:
if (IS_ERR(ipage))
goto unlock_fail;
if (f2fs_has_inline_data(inode)) {
f2fs_put_page(ipage, 1);
f2fs_unlock_op(sbi);
f2fs_put_page(page, 0);
goto repeat;
}
set_new_dnode(&dn, inode, ipage, ipage, 0);
set_new_dnode(&dn, inode, ipage, NULL, 0);
if (f2fs_has_inline_data(inode)) {
if (pos + len <= MAX_INLINE_DATA) {
read_inline_data(page, ipage);
set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
sync_inode_page(&dn);
goto put_next;
} else if (page->index == 0) {
err = f2fs_convert_inline_page(&dn, page);
if (err)
goto unlock_fail;
} else {
struct page *p = grab_cache_page(inode->i_mapping, 0);
if (!p) {
err = -ENOMEM;
goto unlock_fail;
}
err = f2fs_convert_inline_page(&dn, p);
f2fs_put_page(p, 1);
if (err)
goto unlock_fail;
}
}
err = f2fs_reserve_block(&dn, index);
if (err)
goto unlock_fail;
put_next:
f2fs_put_dnode(&dn);
f2fs_unlock_op(sbi);
inline_data:
lock_page(page);
if (unlikely(page->mapping != mapping)) {
f2fs_put_page(page, 1);
goto repeat;
}
f2fs_wait_on_page_writeback(page, DATA);
if ((len == PAGE_CACHE_SIZE) || PageUptodate(page))
return 0;
f2fs_wait_on_page_writeback(page, DATA);
if ((pos & PAGE_CACHE_MASK) >= i_size_read(inode)) {
unsigned start = pos & (PAGE_CACHE_SIZE - 1);
unsigned end = start + len;
@@ -1017,13 +1018,7 @@ inline_data:
goto out;
}
if (f2fs_has_inline_data(inode)) {
err = f2fs_read_inline_data(inode, page);
if (err) {
page_cache_release(page);
goto fail;
}
} else if (dn.data_blkaddr == NEW_ADDR) {
if (dn.data_blkaddr == NEW_ADDR) {
zero_user_segment(page, 0, PAGE_CACHE_SIZE);
} else {
err = f2fs_submit_page_bio(sbi, page, dn.data_blkaddr,
@@ -1049,7 +1044,7 @@ out:
unlock_fail:
f2fs_unlock_op(sbi);
f2fs_put_page(page, 0);
f2fs_put_page(page, 1);
fail:
f2fs_write_failed(mapping, pos + len);
return err;
@@ -1102,9 +1097,12 @@ static ssize_t f2fs_direct_IO(int rw, struct kiocb *iocb,
size_t count = iov_iter_count(iter);
int err;
/* Let buffer I/O handle the inline data case. */
if (f2fs_has_inline_data(inode))
return 0;
/* we don't need to use inline_data strictly */
if (f2fs_has_inline_data(inode)) {
err = f2fs_convert_inline_inode(inode);
if (err)
return err;
}
if (check_direct_IO(inode, rw, iter, offset))
return 0;
@@ -1170,9 +1168,12 @@ static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
{
struct inode *inode = mapping->host;
if (f2fs_has_inline_data(inode))
return 0;
/* we don't need to use inline_data strictly */
if (f2fs_has_inline_data(inode)) {
int err = f2fs_convert_inline_inode(inode);
if (err)
return err;
}
return generic_block_bmap(mapping, block, get_data_block);
}