Commit 151a31b2 authored by Li Zefan's avatar Li Zefan Committed by David Sterba
Browse files

Btrfs: use i_size_read() in btrfs_defrag_file() 



Don't use inode->i_size directly, since we're not holding i_mutex.

This also fixes another bug, that i_size can change after it's checked
against 0 and then (i_size - 1) can be negative.

Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
parent cbcc8326

fs/btrfs/ioctl.c

+4 −3
Original line number Diff line number Diff line
@@ -978,6 +978,7 @@ int btrfs_defrag_file(struct inode *inode, struct file *file, 
	struct btrfs_super_block *disk_super;

	struct file_ra_state *ra = NULL;

	unsigned long last_index;

	u64 isize = i_size_read(inode);

	u64 features;

	u64 last_len = 0;

	u64 skip = 0;
@@ -1003,7 +1004,7 @@ int btrfs_defrag_file(struct inode *inode, struct file *file, 
			compress_type = range->compress_type;

	}



	if (inode->i_size == 0)

	if (isize == 0)

		return 0;



	/*
@@ -1028,10 +1029,10 @@ int btrfs_defrag_file(struct inode *inode, struct file *file, 


	/* find the last page to defrag */

	if (range->start + range->len > range->start) {

		last_index = min_t(u64, inode->i_size - 1,

		last_index = min_t(u64, isize - 1,

			 range->start + range->len - 1) >> PAGE_CACHE_SHIFT;

	} else {

		last_index = (inode->i_size - 1) >> PAGE_CACHE_SHIFT;

		last_index = (isize - 1) >> PAGE_CACHE_SHIFT;

	}



	if (newer_than) {

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