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Commit a1a50f60 authored by Filipe Manana's avatar Filipe Manana Committed by Chris Mason
Browse files

Btrfs: read inode size after acquiring the mutex when punching a hole 



In a previous change, commit 12870f1c,
I accidentally moved the roundup of inode->i_size to outside of the
critical section delimited by the inode mutex, which is not atomic and
not correct since the size can be changed by other task before we acquire
the mutex. Therefore fix it.

Signed-off-by: default avatarFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: default avatarChris Mason <clm@fb.com>
parent 7fb18a06

fs/btrfs/file.c

+2 −1
Original line number Diff line number Diff line
@@ -2187,13 +2187,14 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len) 
	bool same_page = ((offset >> PAGE_CACHE_SHIFT) ==

			  ((offset + len - 1) >> PAGE_CACHE_SHIFT));

	bool no_holes = btrfs_fs_incompat(root->fs_info, NO_HOLES);

	u64 ino_size = round_up(inode->i_size, PAGE_CACHE_SIZE);

	u64 ino_size;



	ret = btrfs_wait_ordered_range(inode, offset, len);

	if (ret)

		return ret;



	mutex_lock(&inode->i_mutex);

	ino_size = round_up(inode->i_size, PAGE_CACHE_SIZE);

	/*

	 * We needn't truncate any page which is beyond the end of the file

	 * because we are sure there is no data there.