From patchwork Mon Aug 15 19:50:43 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Mahoney X-Patchwork-Id: 1068892 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.4) with ESMTP id p7FJrJrU005972 for ; Mon, 15 Aug 2011 19:53:19 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752625Ab1HOTxJ (ORCPT ); Mon, 15 Aug 2011 15:53:09 -0400 Received: from cantor2.suse.de ([195.135.220.15]:48605 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752157Ab1HOTxH (ORCPT ); Mon, 15 Aug 2011 15:53:07 -0400 Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.221.2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx2.suse.de (Postfix) with ESMTP id 251858B2F9 for ; Mon, 15 Aug 2011 21:53:06 +0200 (CEST) Message-Id: <20110815195232.022137466@suse.com> User-Agent: quilt/0.48-18.3 Date: Mon, 15 Aug 2011 15:50:43 -0400 From: Jeff Mahoney To: Btrfs Development List Subject: [patch v2 1/9] btrfs: Add btrfs_panic() References: <20110815195042.559654068@suse.com> Content-Disposition: inline; filename=btrfs-add-btrfs_panic Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Mon, 15 Aug 2011 19:53:19 +0000 (UTC) As part of the effort to eliminate BUG_ON as an error handling technique, we need to determine which errors are actual logic errors, which are on-disk corruption, and which are normal runtime errors e.g. -ENOMEM. Annotating these error cases is helpful to understand and report them. This patch adds a btrfs_panic() routine that will either panic or BUG depending on the new -ofatal_errors={panic,bug} mount option. Since there are still so many BUG_ONs, it defaults to BUG for now but I expect that to change once the error handling effort has made significant progress. Signed-off-by: Jeff Mahoney --- fs/btrfs/ctree.h | 11 +++++++++++ fs/btrfs/super.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 57 insertions(+), 1 deletion(-) -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1363,6 +1363,7 @@ struct btrfs_ioctl_defrag_range_args { #define BTRFS_MOUNT_ENOSPC_DEBUG (1 << 15) #define BTRFS_MOUNT_AUTO_DEFRAG (1 << 16) #define BTRFS_MOUNT_INODE_MAP_CACHE (1 << 17) +#define BTRFS_MOUNT_PANIC_ON_FATAL_ERROR (1 << 18) #define btrfs_clear_opt(o, opt) ((o) &= ~BTRFS_MOUNT_##opt) #define btrfs_set_opt(o, opt) ((o) |= BTRFS_MOUNT_##opt) @@ -2650,6 +2651,16 @@ do { \ __btrfs_std_error((fs_info), __func__, __LINE__, (errno));\ } while (0) +void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function, + unsigned int line, int errno, const char *fmt, ...); + +#define btrfs_panic(fs_info, errno, fmt, args...) \ +do { \ + struct btrfs_fs_info *_i = (fs_info); \ + __btrfs_panic(_i, __func__, __LINE__, errno, fmt, ##args); \ + BUG_ON(!(_i->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR)); \ +} while (0) + /* acl.c */ #ifdef CONFIG_BTRFS_FS_POSIX_ACL struct posix_acl *btrfs_get_acl(struct inode *inode, int type); --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -74,6 +74,9 @@ static const char *btrfs_decode_error(st case -EROFS: errstr = "Readonly filesystem"; break; + case -EEXIST: + errstr = "Object already exists"; + break; default: if (nbuf) { if (snprintf(nbuf, 16, "error %d", -errno) >= 0) @@ -143,6 +146,33 @@ void __btrfs_std_error(struct btrfs_fs_i btrfs_handle_error(fs_info); } +/* + * __btrfs_panic decodes unexpected, fatal errors from the caller, + * issues an alert, and either panics or BUGs, depending on mount options. + */ +void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function, + unsigned int line, int errno, const char *fmt, ...) +{ + struct super_block *sb = fs_info->sb; + char nbuf[16]; + const char *errstr; + struct va_format vaf = { .fmt = fmt }; + va_list args; + + va_start(args, fmt); + vaf.va = &args; + + errstr = btrfs_decode_error(fs_info, errno, nbuf); + if (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR) + panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n", + sb->s_id, function, line, &vaf, errstr); + + printk(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n", + sb->s_id, function, line, &vaf, errstr); + va_end(args); + /* Caller calls BUG() */ +} + static void btrfs_put_super(struct super_block *sb) { struct btrfs_root *root = btrfs_sb(sb); @@ -162,7 +192,7 @@ enum { Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard, Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed, Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, - Opt_inode_cache, Opt_err, + Opt_inode_cache, Opt_fatal_errors, Opt_err, }; static match_table_t tokens = { @@ -195,6 +225,7 @@ static match_table_t tokens = { {Opt_subvolrootid, "subvolrootid=%d"}, {Opt_defrag, "autodefrag"}, {Opt_inode_cache, "inode_cache"}, + {Opt_fatal_errors, "fatal_errors=%s"}, {Opt_err, NULL}, }; @@ -381,6 +412,18 @@ int btrfs_parse_options(struct btrfs_roo printk(KERN_INFO "btrfs: enabling auto defrag"); btrfs_set_opt(info->mount_opt, AUTO_DEFRAG); break; + case Opt_fatal_errors: + if (strcmp(args[0].from, "panic") == 0) + btrfs_set_opt(info->mount_opt, + PANIC_ON_FATAL_ERROR); + else if (strcmp(args[0].from, "bug") == 0) + btrfs_clear_opt(info->mount_opt, + PANIC_ON_FATAL_ERROR); + else { + ret = -EINVAL; + goto out; + } + break; case Opt_err: printk(KERN_INFO "btrfs: unrecognized mount option " "'%s'\n", p); @@ -729,6 +772,8 @@ static int btrfs_show_options(struct seq seq_puts(seq, ",autodefrag"); if (btrfs_test_opt(root, INODE_MAP_CACHE)) seq_puts(seq, ",inode_cache"); + if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR)) + seq_puts(seq, ",fatal_errors=panic"); return 0; }