[PATCH 3/3] f2fs: load largest extent all the time

From: Jaegeuk Kim
Date: Mon Dec 28 2015 - 18:32:06 EST


Otherwise, we can get mismatched largest extent information.

One example is:
1. mount f2fs w/ extent_cache
2. make a small extent
3. umount
4. mount f2fs w/o extent_cache
5. update the largest extent
6. umount
7. mount f2fs w/ extent_cache
8. get the old extent made by #2

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/extent_cache.c | 18 +++++++++++++-----
fs/f2fs/f2fs.h | 2 +-
fs/f2fs/inode.c | 3 ++-
3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
index e7b6548..23e7c82 100644
--- a/fs/f2fs/extent_cache.c
+++ b/fs/f2fs/extent_cache.c
@@ -166,20 +166,27 @@ static void __drop_largest_extent(struct inode *inode,
largest->len = 0;
}

-void f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
+/* return true, if inode page is changed */
+bool f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
struct extent_tree *et;
struct extent_node *en;
struct extent_info ei;

- if (!f2fs_may_extent_tree(inode))
- return;
+ if (!f2fs_may_extent_tree(inode)) {
+ /* drop largest extent */
+ if (i_ext && i_ext->len) {
+ i_ext->len = 0;
+ return true;
+ }
+ return false;
+ }

et = __grab_extent_tree(inode);

- if (!i_ext || le32_to_cpu(i_ext->len) < F2FS_MIN_EXTENT_LEN)
- return;
+ if (!i_ext || !i_ext->len)
+ return false;

set_extent_info(&ei, le32_to_cpu(i_ext->fofs),
le32_to_cpu(i_ext->blk), le32_to_cpu(i_ext->len));
@@ -196,6 +203,7 @@ void f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
}
out:
write_unlock(&et->lock);
+ return false;
}

static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e04b2be..a339508 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2083,7 +2083,7 @@ void f2fs_leave_shrinker(struct f2fs_sb_info *);
* extent_cache.c
*/
unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *, int);
-void f2fs_init_extent_tree(struct inode *, struct f2fs_extent *);
+bool f2fs_init_extent_tree(struct inode *, struct f2fs_extent *);
unsigned int f2fs_destroy_extent_node(struct inode *);
void f2fs_destroy_extent_tree(struct inode *);
bool f2fs_lookup_extent_cache(struct inode *, pgoff_t, struct extent_info *);
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index ec3fb32..e955008 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -138,7 +138,8 @@ static int do_read_inode(struct inode *inode)
fi->i_pino = le32_to_cpu(ri->i_pino);
fi->i_dir_level = ri->i_dir_level;

- f2fs_init_extent_tree(inode, &ri->i_ext);
+ if (f2fs_init_extent_tree(inode, &ri->i_ext))
+ set_page_dirty(node_page);

get_inline_info(fi, ri);

--
2.5.4 (Apple Git-61)

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