[PATCH V2] f2fs: fix to adjust appropirate defragment pg_end

[Zhiguo Niu]

A length that exceeds the real size of the inode may be
specified from user, although these out-of-range areas
are not mapped, but they still need to be check in
while loop, which is unnecessary.

Signed-off-by: Zhiguo Niu <zhiguo.niu@xxxxxxxxxx>
---
v2: check i_size within inode lock according to Chao's suggestions
---
---
 fs/f2fs/file.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 128e53d..cf63db7 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2608,9 +2608,6 @@ static int f2fs_defragment_range(struct f2fs_sb_info *sbi,
 	bool fragmented = false;
 	int err;
 
-	pg_start = range->start >> PAGE_SHIFT;
-	pg_end = (range->start + range->len) >> PAGE_SHIFT;
-
 	f2fs_balance_fs(sbi, true);
 
 	inode_lock(inode);
@@ -2629,10 +2626,16 @@ static int f2fs_defragment_range(struct f2fs_sb_info *sbi,
 
 	/* writeback all dirty pages in the range */
 	err = filemap_write_and_wait_range(inode->i_mapping, range->start,
-						range->start + range->len - 1);
+						min_t(loff_t, range->start + range->len - 1,
+						i_size_read(inode) - 1));
 	if (err)
 		goto out;
 
+	pg_start = range->start >> PAGE_SHIFT;
+	pg_end = min_t(pgoff_t,
+				(range->start + range->len) >> PAGE_SHIFT,
+				DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE));
+
 	/*
 	 * lookup mapping info in extent cache, skip defragmenting if physical
 	 * block addresses are continuous.
-- 
1.9.1