ext4: stop issuing discards if not supported by device

Turn off issuance of discard requests if the device does
not support it - similar to the action we take for barriers.
This will save a little computation time if a non-discardable
device is mounted with -o discard, and also makes it obvious
that it's not doing what was asked at mount time ...

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Eric Sandeen 2010-05-16 03:00:00 -04:00 committed by Theodore Ts'o
parent 6b0310fbf0
commit a30eec2a86

View File

@ -2534,6 +2534,7 @@ static void release_blocks_on_commit(journal_t *journal, transaction_t *txn)
entry->count, entry->group, entry);
if (test_opt(sb, DISCARD)) {
int ret;
ext4_fsblk_t discard_block;
discard_block = entry->start_blk +
@ -2541,7 +2542,12 @@ static void release_blocks_on_commit(journal_t *journal, transaction_t *txn)
trace_ext4_discard_blocks(sb,
(unsigned long long)discard_block,
entry->count);
sb_issue_discard(sb, discard_block, entry->count);
ret = sb_issue_discard(sb, discard_block, entry->count);
if (ret == EOPNOTSUPP) {
ext4_warning(sb,
"discard not supported, disabling");
clear_opt(EXT4_SB(sb)->s_mount_opt, DISCARD);
}
}
err = ext4_mb_load_buddy(sb, entry->group, &e4b);