exofs: Recover in the case of read-passed-end-of-file
In check_io, implement the case of reading passed end of
file, by clearing the pages and recover with no error. In
a raid arrangement this can become a legitimate situation
in case of holes in the file.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
diff --git a/fs/exofs/ios.c b/fs/exofs/ios.c
index 3cc0dd3..439c5d0 100644
--- a/fs/exofs/ios.c
+++ b/fs/exofs/ios.c
@@ -173,6 +173,21 @@
return ret;
}
+static void _clear_bio(struct bio *bio)
+{
+ struct bio_vec *bv;
+ unsigned i;
+
+ __bio_for_each_segment(bv, bio, i, 0) {
+ unsigned this_count = bv->bv_len;
+
+ if (likely(PAGE_SIZE == this_count))
+ clear_highpage(bv->bv_page);
+ else
+ zero_user(bv->bv_page, bv->bv_offset, this_count);
+ }
+}
+
int exofs_check_io(struct exofs_io_state *ios, u64 *resid)
{
enum osd_err_priority acumulated_osd_err = 0;
@@ -181,16 +196,25 @@
for (i = 0; i < ios->numdevs; i++) {
struct osd_sense_info osi;
- int ret = osd_req_decode_sense(ios->per_dev[i].or, &osi);
+ struct osd_request *or = ios->per_dev[i].or;
+ int ret;
+ if (unlikely(!or))
+ continue;
+
+ ret = osd_req_decode_sense(or, &osi);
if (likely(!ret))
continue;
- if (unlikely(ret == -EFAULT)) {
- EXOFS_DBGMSG("%s: EFAULT Need page clear\n", __func__);
- /*FIXME: All the pages in this device range should:
- * clear_highpage(page);
- */
+ if (OSD_ERR_PRI_CLEAR_PAGES == osi.osd_err_pri) {
+ /* start read offset passed endof file */
+ _clear_bio(ios->per_dev[i].bio);
+ EXOFS_DBGMSG("start read offset passed end of file "
+ "offset=0x%llx, length=0x%llx\n",
+ _LLU(ios->offset),
+ _LLU(ios->length));
+
+ continue; /* we recovered */
}
if (osi.osd_err_pri >= acumulated_osd_err) {