[PATCH] f2fs: check truncation of mapping after lock_page

From: Jaegeuk Kim
Date: Mon Apr 29 2013 - 06:22:14 EST


We call lock_page when we need to update a page after readpage.
Between grab and lock page, the page can be truncated by other thread.
So, we should check the page after lock_page whether it was truncated or not.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@xxxxxxxxxxx>
---
fs/f2fs/checkpoint.c | 4 ++++
fs/f2fs/data.c | 18 +++++++++++++++---
fs/f2fs/file.c | 4 ++++
fs/f2fs/node.c | 20 ++++++++++++++++----
4 files changed, 39 insertions(+), 7 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 590ea50..b1de01d 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -65,6 +65,10 @@ repeat:
goto repeat;

lock_page(page);
+ if (page->mapping != mapping) {
+ f2fs_put_page(page, 1);
+ goto repeat;
+ }
out:
mark_page_accessed(page);
return page;
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index eba7e84..2db9380 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -240,7 +240,7 @@ struct page *get_lock_data_page(struct inode *inode, pgoff_t index)

if (dn.data_blkaddr == NULL_ADDR)
return ERR_PTR(-ENOENT);
-
+repeat:
page = grab_cache_page(mapping, index);
if (!page)
return ERR_PTR(-ENOMEM);
@@ -260,6 +260,10 @@ struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
f2fs_put_page(page, 1);
return ERR_PTR(-EIO);
}
+ if (page->mapping != mapping) {
+ f2fs_put_page(page, 1);
+ goto repeat;
+ }
return page;
}

@@ -291,7 +295,7 @@ struct page *get_new_data_page(struct inode *inode, pgoff_t index,
}
}
f2fs_put_dnode(&dn);
-
+repeat:
page = grab_cache_page(mapping, index);
if (!page)
return ERR_PTR(-ENOMEM);
@@ -311,6 +315,10 @@ struct page *get_new_data_page(struct inode *inode, pgoff_t index,
f2fs_put_page(page, 1);
return ERR_PTR(-EIO);
}
+ if (page->mapping != mapping) {
+ f2fs_put_page(page, 1);
+ goto repeat;
+ }
}

if (new_i_size &&
@@ -611,7 +619,7 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping,
*fsdata = NULL;

f2fs_balance_fs(sbi);
-
+repeat:
page = grab_cache_page_write_begin(mapping, index, flags);
if (!page)
return -ENOMEM;
@@ -656,6 +664,10 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping,
f2fs_put_page(page, 1);
return -EIO;
}
+ if (page->mapping != mapping) {
+ f2fs_put_page(page, 1);
+ goto repeat;
+ }
}
out:
SetPageUptodate(page);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 9dfcdab..3e2c2cb 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -217,6 +217,10 @@ static void truncate_partial_data_page(struct inode *inode, u64 from)
return;

lock_page(page);
+ if (page->mapping != inode->i_mapping) {
+ f2fs_put_page(page, 1);
+ return;
+ }
wait_on_page_writeback(page);
zero_user(page, offset, PAGE_CACHE_SIZE - offset);
set_page_dirty(page);
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index aede910..6ff0172 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -674,6 +674,7 @@ fail:
int truncate_inode_blocks(struct inode *inode, pgoff_t from)
{
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+ struct address_space *node_mapping = sbi->node_inode->i_mapping;
int err = 0, cont = 1;
int level, offset[4], noffset[4];
unsigned int nofs = 0;
@@ -684,7 +685,7 @@ int truncate_inode_blocks(struct inode *inode, pgoff_t from)
trace_f2fs_truncate_inode_blocks_enter(inode, from);

level = get_node_path(from, offset, noffset);
-
+restart:
page = get_node_page(sbi, inode->i_ino);
if (IS_ERR(page)) {
trace_f2fs_truncate_inode_blocks_exit(inode, PTR_ERR(page));
@@ -748,6 +749,10 @@ skip_partial:
if (offset[1] == 0 &&
rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK]) {
lock_page(page);
+ if (page->mapping != node_mapping) {
+ f2fs_put_page(page, 1);
+ goto restart;
+ }
wait_on_page_writeback(page);
rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK] = 0;
set_page_dirty(page);
@@ -916,7 +921,7 @@ struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
struct address_space *mapping = sbi->node_inode->i_mapping;
struct page *page;
int err;
-
+repeat:
page = grab_cache_page(mapping, nid);
if (!page)
return ERR_PTR(-ENOMEM);
@@ -932,6 +937,10 @@ struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
f2fs_put_page(page, 1);
return ERR_PTR(-EIO);
}
+ if (page->mapping != mapping) {
+ f2fs_put_page(page, 1);
+ goto repeat;
+ }
got_it:
BUG_ON(nid != nid_of_node(page));
mark_page_accessed(page);
@@ -955,7 +964,7 @@ struct page *get_node_page_ra(struct page *parent, int start)
nid = get_nid(parent, start, false);
if (!nid)
return ERR_PTR(-ENOENT);
-
+repeat:
page = grab_cache_page(mapping, nid);
if (!page)
return ERR_PTR(-ENOMEM);
@@ -981,7 +990,10 @@ struct page *get_node_page_ra(struct page *parent, int start)
blk_finish_plug(&plug);

lock_page(page);
-
+ if (page->mapping != mapping) {
+ f2fs_put_page(page, 1);
+ goto repeat;
+ }
page_hit:
if (!PageUptodate(page)) {
f2fs_put_page(page, 1);
--
1.8.1.3.566.gaa39828

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