1 files changed, 10 insertions, 16 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 91c98a6d1408..35cfc738f6b7 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -3356,13 +3356,14 @@ static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct extent_map *em = NULL;
 	struct extent_state *cached_state = NULL;
+	loff_t i_size = inode->i_size;
 	u64 lockstart;
 	u64 lockend;
 	u64 start;
 	u64 len;
 	int ret = 0;
 
-	if (inode->i_size == 0)
+	if (i_size == 0 || *offset >= i_size)
 		return -ENXIO;
 
 	/*
@@ -3372,8 +3373,7 @@ static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
 	start = max_t(loff_t, 0, *offset);
 
 	lockstart = round_down(start, fs_info->sectorsize);
-	lockend = round_up(i_size_read(inode),
-			   fs_info->sectorsize);
+	lockend = round_up(i_size, fs_info->sectorsize);
 	if (lockend <= lockstart)
 		lockend = lockstart + fs_info->sectorsize;
 	lockend--;
@@ -3382,7 +3382,7 @@ static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
 	lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
 			 &cached_state);
 
-	while (start < inode->i_size) {
+	while (start < i_size) {
 		em = btrfs_get_extent_fiemap(BTRFS_I(inode), start, len);
 		if (IS_ERR(em)) {
 			ret = PTR_ERR(em);
@@ -3406,10 +3406,10 @@ static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
 	}
 	free_extent_map(em);
 	if (!ret) {
-		if (whence == SEEK_DATA && start >= inode->i_size)
+		if (whence == SEEK_DATA && start >= i_size)
 			ret = -ENXIO;
 		else
-			*offset = min_t(loff_t, start, inode->i_size);
+			*offset = min_t(loff_t, start, i_size);
 	}
 	unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
 			     &cached_state);
@@ -3421,7 +3421,6 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
 	struct inode *inode = file->f_mapping->host;
 	int ret;
 
-	inode_lock(inode);
 	switch (whence) {
 	case SEEK_END:
 	case SEEK_CUR:
@@ -3429,21 +3428,16 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
 		goto out;
 	case SEEK_DATA:
 	case SEEK_HOLE:
-		if (offset >= i_size_read(inode)) {
-			inode_unlock(inode);
-			return -ENXIO;
-		}
-
+		inode_lock_shared(inode);
 		ret = find_desired_extent(inode, &offset, whence);
-		if (ret) {
-			inode_unlock(inode);
+		inode_unlock_shared(inode);
+
+		if (ret)
 			return ret;
-		}
 	}
 
 	offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
 out:
-	inode_unlock(inode);
 	return offset;
 }