From 151a31b25e5c941bdd9fdefed650effca223c716 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 2 Sep 2011 15:56:39 +0800 Subject: [PATCH] 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: Li Zefan --- fs/btrfs/ioctl.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index b39f7bf92704..323d77f09258 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -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) { -- 2.39.5