From: Eric Sandeen Date: Sun, 16 May 2010 07:00:00 +0000 (-0400) Subject: ext4: stop issuing discards if not supported by device X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=a30eec2a8;p=linux-beck.git 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 Signed-off-by: "Theodore Ts'o" --- diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 8639d5a637b2..4f2d3a9d4e21 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -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);