From 74ef00185eb864252156022ff129b01549504175 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Thu, 4 Jun 2020 15:18:06 +0800 Subject: [PATCH] btrfs: introduce "rescue=" mount option This patch introduces a new "rescue=" mount option group for all mount options for data recovery. Different rescue sub options are seperated by ':'. E.g "ro,rescue=nologreplay:usebackuproot". The original plan was to use ';', but ';' needs to be escaped/quoted, or it will be interpreted by bash, similar to '|'. And obviously, user can specify rescue options one by one like: "ro,rescue=nologreplay,rescue=usebackuproot". The following mount options are converted to "rescue=", old mount options are deprecated but still available for compatibility purpose: - usebackuproot Now it's "rescue=usebackuproot" - nologreplay Now it's "rescue=nologreplay" Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/super.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 73 insertions(+), 8 deletions(-) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index c3826ae..76ab6d5 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -326,7 +326,6 @@ enum { Opt_defrag, Opt_nodefrag, Opt_discard, Opt_nodiscard, Opt_discard_mode, - Opt_nologreplay, Opt_norecovery, Opt_ratio, Opt_rescan_uuid_tree, @@ -340,9 +339,13 @@ enum { Opt_subvolid, Opt_thread_pool, Opt_treelog, Opt_notreelog, - Opt_usebackuproot, Opt_user_subvol_rm_allowed, + /* Rescue options */ + Opt_rescue, + Opt_usebackuproot, + Opt_nologreplay, + /* Deprecated options */ Opt_alloc_start, Opt_recovery, @@ -390,7 +393,6 @@ static const match_table_t tokens = { {Opt_discard, "discard"}, {Opt_discard_mode, "discard=%s"}, {Opt_nodiscard, "nodiscard"}, - {Opt_nologreplay, "nologreplay"}, {Opt_norecovery, "norecovery"}, {Opt_ratio, "metadata_ratio=%u"}, {Opt_rescan_uuid_tree, "rescan_uuid_tree"}, @@ -408,9 +410,15 @@ static const match_table_t tokens = { {Opt_thread_pool, "thread_pool=%u"}, {Opt_treelog, "treelog"}, {Opt_notreelog, "notreelog"}, - {Opt_usebackuproot, "usebackuproot"}, {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"}, + /* Rescue options */ + {Opt_rescue, "rescue=%s"}, + /* Deprecated, with alias rescue=nologreplay */ + {Opt_nologreplay, "nologreplay"}, + /* Deprecated, with alias rescue=usebackuproot */ + {Opt_usebackuproot, "usebackuproot"}, + /* Deprecated options */ {Opt_alloc_start, "alloc_start=%s"}, {Opt_recovery, "recovery"}, @@ -433,6 +441,55 @@ static const match_table_t tokens = { {Opt_err, NULL}, }; +static const match_table_t rescue_tokens = { + {Opt_usebackuproot, "usebackuproot"}, + {Opt_nologreplay, "nologreplay"}, + {Opt_err, NULL}, +}; + +static int parse_rescue_options(struct btrfs_fs_info *info, const char *options) +{ + char *opts; + char *orig; + char *p; + substring_t args[MAX_OPT_ARGS]; + int ret = 0; + + opts = kstrdup(options, GFP_KERNEL); + if (!opts) + return -ENOMEM; + orig = opts; + + while ((p = strsep(&opts, ":")) != NULL) { + int token; + + if (!*p) + continue; + token = match_token(p, rescue_tokens, args); + switch (token){ + case Opt_usebackuproot: + btrfs_info(info, + "trying to use backup root at mount time"); + btrfs_set_opt(info->mount_opt, USEBACKUPROOT); + break; + case Opt_nologreplay: + btrfs_set_and_info(info, NOLOGREPLAY, + "disabling log replay at mount time"); + break; + case Opt_err: + btrfs_info(info, "unrecognized rescue option '%s'", p); + ret = -EINVAL; + goto out; + default: + break; + } + + } +out: + kfree(orig); + return ret; +} + /* * Regular mount options parser. Everything that is needed only when * reading in a new superblock is parsed here. @@ -689,6 +746,8 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options, break; case Opt_norecovery: case Opt_nologreplay: + btrfs_warn(info, + "'nologreplay' is deprecated, use 'rescue=nologreplay' instead"); btrfs_set_and_info(info, NOLOGREPLAY, "disabling log replay at mount time"); break; @@ -791,10 +850,11 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options, "disabling auto defrag"); break; case Opt_recovery: - btrfs_warn(info, - "'recovery' is deprecated, use 'usebackuproot' instead"); - fallthrough; case Opt_usebackuproot: + btrfs_warn(info, + "'%s' is deprecated, use 'rescue=usebackuproot' instead", + token == Opt_recovery ? "recovery" : + "usebackuproot"); btrfs_info(info, "trying to use backup root at mount time"); btrfs_set_opt(info->mount_opt, USEBACKUPROOT); @@ -859,6 +919,11 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options, } info->commit_interval = intarg; break; + case Opt_rescue: + ret = parse_rescue_options(info, args[0].from); + if (ret < 0) + goto out; + break; #ifdef CONFIG_BTRFS_DEBUG case Opt_fragment_all: btrfs_info(info, "fragmenting all space"); @@ -1344,7 +1409,7 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) if (btrfs_test_opt(info, NOTREELOG)) seq_puts(seq, ",notreelog"); if (btrfs_test_opt(info, NOLOGREPLAY)) - seq_puts(seq, ",nologreplay"); + seq_puts(seq, ",rescue=nologreplay"); if (btrfs_test_opt(info, FLUSHONCOMMIT)) seq_puts(seq, ",flushoncommit"); if (btrfs_test_opt(info, DISCARD_SYNC)) -- 2.7.4