On 09/28/16 17:39, Darrick J. Wong wrote:
+ if (end > isize) {
+ if (mode & FALLOC_FL_KEEP_SIZE) {
+ len = isize - start;
+ end = start + len - 1;
+ } else
+ return -EINVAL;
+ }
If FALLOC_FL_KEEP_SIZE has been set and end == isize the above code
won't reduce end to isize - 1. Shouldn't "end > isize" be changed into
"end >= isize" ?
+ switch (mode) {
+ case FALLOC_FL_ZERO_RANGE:
+ case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE:
+ error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
+ GFP_KERNEL, false);
+ if (error)
+ return error;
+ break;
+ case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE:
+ /* Only punch if the device can do zeroing discard. */
+ if (!blk_queue_discard(q) || !q->limits.discard_zeroes_data)
+ return -EOPNOTSUPP;
+ error = blkdev_issue_discard(bdev, start >> 9, len >> 9,
+ GFP_KERNEL, 0);
+ if (error)
+ return error;
+ break;
+ case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE |
FALLOC_FL_NO_HIDE_STALE:
+ error = blkdev_issue_discard(bdev, start >> 9, len >> 9,
+ GFP_KERNEL, 0);
+ if (error)
+ return error;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
Have you considered to move "if (error) return error" out of the switch
statement?
+ /*
+ * Invalidate again; if someone wandered in and dirtied a page,
+ * the caller will be given -EBUSY;
+ */
+ return invalidate_inode_pages2_range(mapping,
+ start >> PAGE_SHIFT,
+ end >> PAGE_SHIFT);
A comment might be appropriate here that since end is inclusive and
since the third argument of invalidate_inode_pages2_range() is inclusive
that rounding down will yield the correct result.
Bart.
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