From: =?ISO-8859-15?Q?Luk=E1=A8_Czerner?= Subject: Re: [PATCH] ext4: add error handling when discard cmd is fail in FITRIM Date: Mon, 30 Jul 2012 13:31:39 +0200 (CEST) Message-ID: References: <1343561514-8380-1-git-send-email-linkinjeon@gmail.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: tytso@mit.edu, sandeen@redhat.com, lczerner@redhat.com, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, Amit Sahrawat To: Namjae Jeon Return-path: Received: from mx1.redhat.com ([209.132.183.28]:56292 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753178Ab2G3Lbs (ORCPT ); Mon, 30 Jul 2012 07:31:48 -0400 In-Reply-To: <1343561514-8380-1-git-send-email-linkinjeon@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sun, 29 Jul 2012, Namjae Jeon wrote: > Date: Sun, 29 Jul 2012 07:31:54 -0400 > From: Namjae Jeon > To: tytso@mit.edu, sandeen@redhat.com, lczerner@redhat.com, > linux-ext4@vger.kernel.org > Cc: linux-kernel@vger.kernel.org, Namjae Jeon , > Amit Sahrawat > Subject: [PATCH] ext4: add error handling when discard cmd is fail in FITRIM > > Although free extents is proper not trimmed(mmc driver return error code > while sending trim command), currently FITRIM ioctl return success. > Add exception routine to inform user error code. > > #> ./fitrim_test > end_request: I/O error, dev mmcblk0, sector 27232 > EXT4-fs warning (device mmcblk0): ext4_trim_all_free:4857: > Discard command returned error -5 > #> Well, by this change you're actually reverting commit d9f34504e6952e909a6932c5b2d1857716606380 ext4: ignore errors when issuing discards which effectively reverts a30eec2a8. Now I think that the way it is now is actually better than your proposal for the reasons mentioned in the commit d9f34504e6952e909a6932c5b2d1857716606380. However I think that the discard errors should be logged nevertheless but not at the file system level, but rather on block layer level if it is not done already. Thanks! -Lukas > > Signed-off-by: Namjae Jeon > Signed-off-by: Amit Sahrawat > Reviewed-by: Jan Kara > --- > fs/ext4/mballoc.c | 25 +++++++++++++++++-------- > 1 file changed, 17 insertions(+), 8 deletions(-) > > diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c > index 8eae947..07569b6 100644 > --- a/fs/ext4/mballoc.c > +++ b/fs/ext4/mballoc.c > @@ -4852,10 +4852,11 @@ error_return: > * one will allocate those blocks, mark it as used in buddy bitmap. This must > * be called with under the group lock. > */ > -static void ext4_trim_extent(struct super_block *sb, int start, int count, > +static int ext4_trim_extent(struct super_block *sb, int start, int count, > ext4_group_t group, struct ext4_buddy *e4b) > { > struct ext4_free_extent ex; > + int err; > > trace_ext4_trim_extent(sb, group, start, count); > > @@ -4871,9 +4872,10 @@ static void ext4_trim_extent(struct super_block *sb, int start, int count, > */ > mb_mark_used(e4b, &ex); > ext4_unlock_group(sb, group); > - ext4_issue_discard(sb, group, start, count); > + err = ext4_issue_discard(sb, group, start, count); > ext4_lock_group(sb, group); > mb_free_blocks(NULL, e4b, start, ex.fe_len); > + return err; > } > > /** > @@ -4902,7 +4904,7 @@ ext4_trim_all_free(struct super_block *sb, ext4_group_t group, > void *bitmap; > ext4_grpblk_t next, count = 0, free_count = 0; > struct ext4_buddy e4b; > - int ret; > + int ret = 0; > > trace_ext4_trim_all_free(sb, group, start, max); > > @@ -4929,15 +4931,22 @@ ext4_trim_all_free(struct super_block *sb, ext4_group_t group, > next = mb_find_next_bit(bitmap, max + 1, start); > > if ((next - start) >= minblocks) { > - ext4_trim_extent(sb, start, > - next - start, group, &e4b); > - count += next - start; > + ret = ext4_trim_extent(sb, start, > + next - start, group, &e4b); > + if (ret < 0) { > + if (ret != -EOPNOTSUPP) > + ext4_warning(sb, > + "Discard command returned error %d\n", > + ret); > + break; > + } else > + count += next - start; > } > free_count += next - start; > start = next + 1; > > if (fatal_signal_pending(current)) { > - count = -ERESTARTSYS; > + ret = -ERESTARTSYS; > break; > } > > @@ -4960,7 +4969,7 @@ out: > ext4_debug("trimmed %d blocks in the group %d\n", > count, group); > > - return count; > + return (ret < 0) ? ret : count; > } > > /** >