On Fri, Sep 02, 2011 at 03:56:39PM +0800, Li Zefan wrote:
> 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 <lizf@xxxxxxxxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxx>
> ---
> fs/btrfs/ioctl.c | 7 ++++---
> 1 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 31fe6d4..6f2b257 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -972,6 +972,7 @@ 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;
> @@ -997,7 +998,7 @@ 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;
>
> /*
> @@ -1022,10 +1023,10 @@ 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) {
> --
> 1.7.3.1
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
