f2fs: revisit inline_data to avoid data races and potential bugs
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>
diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
index d6677d6..8b66109 100644
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -15,41 +15,26 @@
bool f2fs_may_inline(struct inode *inode)
{
- block_t nr_blocks;
- loff_t i_size;
-
if (!test_opt(F2FS_I_SB(inode), INLINE_DATA))
return false;
if (f2fs_is_atomic_file(inode))
return false;
- nr_blocks = F2FS_I(inode)->i_xattr_nid ? 3 : 2;
- if (inode->i_blocks > nr_blocks)
- return false;
-
- i_size = i_size_read(inode);
- if (i_size > MAX_INLINE_DATA)
+ if (!S_ISREG(inode->i_mode))
return false;
return true;
}
-int f2fs_read_inline_data(struct inode *inode, struct page *page)
+void read_inline_data(struct page *page, struct page *ipage)
{
- struct page *ipage;
void *src_addr, *dst_addr;
- if (page->index) {
- zero_user_segment(page, 0, PAGE_CACHE_SIZE);
- goto out;
- }
+ if (PageUptodate(page))
+ return;
- ipage = get_node_page(F2FS_I_SB(inode), inode->i_ino);
- if (IS_ERR(ipage)) {
- unlock_page(page);
- return PTR_ERR(ipage);
- }
+ f2fs_bug_on(F2FS_P_SB(page), page->index);
zero_user_segment(page, MAX_INLINE_DATA, PAGE_CACHE_SIZE);
@@ -59,104 +44,120 @@
memcpy(dst_addr, src_addr, MAX_INLINE_DATA);
flush_dcache_page(page);
kunmap_atomic(dst_addr);
- f2fs_put_page(ipage, 1);
-out:
SetPageUptodate(page);
- unlock_page(page);
+}
+int f2fs_read_inline_data(struct inode *inode, struct page *page)
+{
+ struct page *ipage;
+
+ ipage = get_node_page(F2FS_I_SB(inode), inode->i_ino);
+ if (IS_ERR(ipage)) {
+ unlock_page(page);
+ return PTR_ERR(ipage);
+ }
+
+ if (!f2fs_has_inline_data(inode)) {
+ f2fs_put_page(ipage, 1);
+ return -EAGAIN;
+ }
+
+ if (page->index)
+ zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+ else
+ read_inline_data(page, ipage);
+
+ SetPageUptodate(page);
+ f2fs_put_page(ipage, 1);
+ unlock_page(page);
return 0;
}
-static int __f2fs_convert_inline_data(struct inode *inode, struct page *page)
+int f2fs_convert_inline_page(struct dnode_of_data *dn, struct page *page)
{
- int err = 0;
- struct page *ipage;
- struct dnode_of_data dn;
void *src_addr, *dst_addr;
block_t new_blk_addr;
- struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
struct f2fs_io_info fio = {
.type = DATA,
.rw = WRITE_SYNC | REQ_PRIO,
};
+ int err;
- f2fs_lock_op(sbi);
- ipage = get_node_page(sbi, inode->i_ino);
- if (IS_ERR(ipage)) {
- err = PTR_ERR(ipage);
- goto out;
- }
+ f2fs_bug_on(F2FS_I_SB(dn->inode), page->index);
- /* someone else converted inline_data already */
- if (!f2fs_has_inline_data(inode))
- goto out;
+ if (!f2fs_exist_data(dn->inode))
+ goto clear_out;
- /*
- * i_addr[0] is not used for inline data,
- * so reserving new block will not destroy inline data
- */
- set_new_dnode(&dn, inode, ipage, NULL, 0);
- err = f2fs_reserve_block(&dn, 0);
+ err = f2fs_reserve_block(dn, 0);
if (err)
- goto out;
+ return err;
f2fs_wait_on_page_writeback(page, DATA);
+
+ if (PageUptodate(page))
+ goto no_update;
+
zero_user_segment(page, MAX_INLINE_DATA, PAGE_CACHE_SIZE);
/* Copy the whole inline data block */
- src_addr = inline_data_addr(ipage);
+ src_addr = inline_data_addr(dn->inode_page);
dst_addr = kmap_atomic(page);
memcpy(dst_addr, src_addr, MAX_INLINE_DATA);
kunmap_atomic(dst_addr);
SetPageUptodate(page);
-
+no_update:
/* write data page to try to make data consistent */
set_page_writeback(page);
- write_data_page(page, &dn, &new_blk_addr, &fio);
- update_extent_cache(new_blk_addr, &dn);
+
+ write_data_page(page, dn, &new_blk_addr, &fio);
+ update_extent_cache(new_blk_addr, dn);
f2fs_wait_on_page_writeback(page, DATA);
/* clear inline data and flag after data writeback */
- zero_user_segment(ipage, INLINE_DATA_OFFSET,
- INLINE_DATA_OFFSET + MAX_INLINE_DATA);
- clear_inode_flag(F2FS_I(inode), FI_INLINE_DATA);
- stat_dec_inline_inode(inode);
-
- sync_inode_page(&dn);
- f2fs_put_dnode(&dn);
-out:
- f2fs_unlock_op(sbi);
- return err;
+ truncate_inline_data(dn->inode_page, 0);
+clear_out:
+ f2fs_clear_inline_inode(dn->inode);
+ stat_dec_inline_inode(dn->inode);
+ sync_inode_page(dn);
+ f2fs_put_dnode(dn);
+ return 0;
}
-int f2fs_convert_inline_data(struct inode *inode, pgoff_t to_size,
- struct page *page)
+int f2fs_convert_inline_inode(struct inode *inode)
{
- struct page *new_page = page;
- int err;
+ struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ struct dnode_of_data dn;
+ struct page *ipage, *page;
+ int err = 0;
- if (!f2fs_has_inline_data(inode))
- return 0;
- else if (to_size <= MAX_INLINE_DATA)
- return 0;
+ page = grab_cache_page(inode->i_mapping, 0);
+ if (!page)
+ return -ENOMEM;
- if (!page || page->index != 0) {
- new_page = grab_cache_page(inode->i_mapping, 0);
- if (!new_page)
- return -ENOMEM;
+ f2fs_lock_op(sbi);
+
+ ipage = get_node_page(sbi, inode->i_ino);
+ if (IS_ERR(ipage)) {
+ f2fs_unlock_op(sbi);
+ return PTR_ERR(ipage);
}
- err = __f2fs_convert_inline_data(inode, new_page);
- if (!page || page->index != 0)
- f2fs_put_page(new_page, 1);
+ set_new_dnode(&dn, inode, ipage, ipage, 0);
+
+ if (f2fs_has_inline_data(inode))
+ err = f2fs_convert_inline_page(&dn, page);
+
+ f2fs_put_dnode(&dn);
+
+ f2fs_unlock_op(sbi);
+
+ f2fs_put_page(page, 1);
return err;
}
-int f2fs_write_inline_data(struct inode *inode,
- struct page *page, unsigned size)
+int f2fs_write_inline_data(struct inode *inode, struct page *page)
{
void *src_addr, *dst_addr;
- struct page *ipage;
struct dnode_of_data dn;
int err;
@@ -164,48 +165,39 @@
err = get_dnode_of_data(&dn, 0, LOOKUP_NODE);
if (err)
return err;
- ipage = dn.inode_page;
- /* Release any data block if it is allocated */
if (!f2fs_has_inline_data(inode)) {
- int count = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
- truncate_data_blocks_range(&dn, count);
- set_inode_flag(F2FS_I(inode), FI_INLINE_DATA);
- stat_inc_inline_inode(inode);
+ f2fs_put_dnode(&dn);
+ return -EAGAIN;
}
- f2fs_wait_on_page_writeback(ipage, NODE);
- zero_user_segment(ipage, INLINE_DATA_OFFSET,
- INLINE_DATA_OFFSET + MAX_INLINE_DATA);
+ f2fs_bug_on(F2FS_I_SB(inode), page->index);
+
+ f2fs_wait_on_page_writeback(dn.inode_page, NODE);
src_addr = kmap_atomic(page);
- dst_addr = inline_data_addr(ipage);
- memcpy(dst_addr, src_addr, size);
+ dst_addr = inline_data_addr(dn.inode_page);
+ memcpy(dst_addr, src_addr, MAX_INLINE_DATA);
kunmap_atomic(src_addr);
set_inode_flag(F2FS_I(inode), FI_APPEND_WRITE);
+ set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
+
sync_inode_page(&dn);
f2fs_put_dnode(&dn);
-
return 0;
}
-void truncate_inline_data(struct inode *inode, u64 from)
+void truncate_inline_data(struct page *ipage, u64 from)
{
- struct page *ipage;
+ void *addr;
if (from >= MAX_INLINE_DATA)
return;
- ipage = get_node_page(F2FS_I_SB(inode), inode->i_ino);
- if (IS_ERR(ipage))
- return;
-
f2fs_wait_on_page_writeback(ipage, NODE);
- zero_user_segment(ipage, INLINE_DATA_OFFSET + from,
- INLINE_DATA_OFFSET + MAX_INLINE_DATA);
- set_page_dirty(ipage);
- f2fs_put_page(ipage, 1);
+ addr = inline_data_addr(ipage);
+ memset(addr + from, 0, MAX_INLINE_DATA - from);
}
bool recover_inline_data(struct inode *inode, struct page *npage)
@@ -237,6 +229,10 @@
src_addr = inline_data_addr(npage);
dst_addr = inline_data_addr(ipage);
memcpy(dst_addr, src_addr, MAX_INLINE_DATA);
+
+ set_inode_flag(F2FS_I(inode), FI_INLINE_DATA);
+ set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
+
update_inode(inode, ipage);
f2fs_put_page(ipage, 1);
return true;
@@ -245,15 +241,12 @@
if (f2fs_has_inline_data(inode)) {
ipage = get_node_page(sbi, inode->i_ino);
f2fs_bug_on(sbi, IS_ERR(ipage));
- f2fs_wait_on_page_writeback(ipage, NODE);
- zero_user_segment(ipage, INLINE_DATA_OFFSET,
- INLINE_DATA_OFFSET + MAX_INLINE_DATA);
- clear_inode_flag(F2FS_I(inode), FI_INLINE_DATA);
+ truncate_inline_data(ipage, 0);
+ f2fs_clear_inline_inode(inode);
update_inode(inode, ipage);
f2fs_put_page(ipage, 1);
} else if (ri && (ri->i_inline & F2FS_INLINE_DATA)) {
truncate_blocks(inode, 0, false);
- set_inode_flag(F2FS_I(inode), FI_INLINE_DATA);
goto process_inline;
}
return false;
@@ -366,8 +359,8 @@
set_page_dirty(page);
/* clear inline dir and flag after data writeback */
- zero_user_segment(ipage, INLINE_DATA_OFFSET,
- INLINE_DATA_OFFSET + MAX_INLINE_DATA);
+ truncate_inline_data(ipage, 0);
+
stat_dec_inline_dir(dir);
clear_inode_flag(F2FS_I(dir), FI_INLINE_DENTRY);