Messages in this thread Patch in this message | | | Date | Sun, 18 Sep 2011 15:29:41 +0800 | From | Jeff Liu <> | Subject | Re: [PATCH 1/7] BTRFS: Fix lseek return value for error |
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Hi Andreas and Andi,
Thanks for your comments.
On 09/18/2011 09:46 AM, Andi Kleen wrote:
>>> with an additional improvement if the offset is larger or equal to the >>> file size, return -ENXIO in directly: >>> >>> if (offset >= inode->i_size) { >>> mutex_unlock(&inode->i_mutex); >>> return -ENXIO; >>> } >> >> Except that is wrong, because it would then be impossible to write sparse files.
Per my tryout, except that, if the offset >= source file size, call lseek(fd, offset, SEEK_DATA/SEEK_HOLE) against Btrfs will always return the total file size rather than -ENXIO. however, our desired result it -ENXIO in this case, Am I right?
> > And also i_size must be always read with i_size_read()
Thanks for pointing this out! Would you please kindly review the revised as below?
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
--- fs/btrfs/file.c | 9 +++++++-- 1 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index e7872e4..40c1ef3 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1813,6 +1813,11 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int origin) goto out; case SEEK_DATA: case SEEK_HOLE: + if (offset >= i_size_read(inode)) { + mutex_unlock(&inode->i_mutex); + return -ENXIO; + } + ret = find_desired_extent(inode, &offset, origin); if (ret) { mutex_unlock(&inode->i_mutex); @@ -1821,11 +1826,11 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int origin) }
if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) { - ret = -EINVAL; + offset = -EINVAL; goto out; } if (offset > inode->i_sb->s_maxbytes) { - ret = -EINVAL; + offset = -EINVAL; goto out; }
-- 1.7.4.1
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