From 0234576d041b9b2cc7043691ea61d2c2ca597aaa Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Fri, 20 Nov 2009 03:28:01 +0900 Subject: [PATCH] nilfs2: add norecovery mount option This adds "norecovery" mount option which disables temporal write access to read-only mounts or snapshots during mount/recovery. Without this option, write access will be even performed for those types of mounts; the temporal write access is needed to mount root file system read-only after an unclean shutdown. This option will be helpful when user wants to prevent any write access to the device. Signed-off-by: Ryusuke Konishi Cc: Eric Sandeen --- Documentation/filesystems/nilfs2.txt | 4 ++++ fs/nilfs2/super.c | 16 +++++++++++++++- fs/nilfs2/the_nilfs.c | 20 ++++++++++++++++++-- include/linux/nilfs2_fs.h | 2 ++ 4 files changed, 39 insertions(+), 3 deletions(-) diff --git a/Documentation/filesystems/nilfs2.txt b/Documentation/filesystems/nilfs2.txt index cbd877978c80..4949fcaa6b6a 100644 --- a/Documentation/filesystems/nilfs2.txt +++ b/Documentation/filesystems/nilfs2.txt @@ -70,6 +70,10 @@ order=strict Apply strict in-order semantics that preserves sequence blocks. That means, it is guaranteed that no overtaking of events occurs in the recovered file system after a crash. +norecovery Disable recovery of the filesystem on mount. + This disables every write access on the device for + read-only mounts or snapshots. This option will fail + for r/w mounts on an unclean volume. NILFS2 usage ============ diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c index 990ead43a833..5403b3ef3a42 100644 --- a/fs/nilfs2/super.c +++ b/fs/nilfs2/super.c @@ -479,6 +479,8 @@ static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs) seq_printf(seq, ",errors=panic"); if (nilfs_test_opt(sbi, STRICT_ORDER)) seq_printf(seq, ",order=strict"); + if (nilfs_test_opt(sbi, NORECOVERY)) + seq_printf(seq, ",norecovery"); return 0; } @@ -547,7 +549,7 @@ static const struct export_operations nilfs_export_ops = { enum { Opt_err_cont, Opt_err_panic, Opt_err_ro, - Opt_nobarrier, Opt_snapshot, Opt_order, + Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery, Opt_err, }; @@ -558,6 +560,7 @@ static match_table_t tokens = { {Opt_nobarrier, "nobarrier"}, {Opt_snapshot, "cp=%u"}, {Opt_order, "order=%s"}, + {Opt_norecovery, "norecovery"}, {Opt_err, NULL} }; @@ -608,6 +611,9 @@ static int parse_options(char *options, struct super_block *sb) sbi->s_snapshot_cno = option; nilfs_set_opt(sbi, SNAPSHOT); break; + case Opt_norecovery: + nilfs_set_opt(sbi, NORECOVERY); + break; default: printk(KERN_ERR "NILFS: Unrecognized mount option \"%s\"\n", p); @@ -863,6 +869,14 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data) goto restore_opts; } + if (!nilfs_valid_fs(nilfs)) { + printk(KERN_WARNING "NILFS (device %s): couldn't " + "remount because the filesystem is in an " + "incomplete recovery state.\n", sb->s_id); + err = -EINVAL; + goto restore_opts; + } + if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) goto out; if (*flags & MS_RDONLY) { diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c index 890a8d3886cf..6241e1722efc 100644 --- a/fs/nilfs2/the_nilfs.c +++ b/fs/nilfs2/the_nilfs.c @@ -264,8 +264,14 @@ int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi) int valid_fs = nilfs_valid_fs(nilfs); int err; - if (nilfs_loaded(nilfs)) - return 0; + if (nilfs_loaded(nilfs)) { + if (valid_fs || + ((s_flags & MS_RDONLY) && nilfs_test_opt(sbi, NORECOVERY))) + return 0; + printk(KERN_ERR "NILFS: the filesystem is in an incomplete " + "recovery state.\n"); + return -EINVAL; + } if (!valid_fs) { printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n"); @@ -295,6 +301,11 @@ int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi) goto skip_recovery; if (s_flags & MS_RDONLY) { + if (nilfs_test_opt(sbi, NORECOVERY)) { + printk(KERN_INFO "NILFS: norecovery option specified. " + "skipping roll-forward recovery\n"); + goto skip_recovery; + } if (really_read_only) { printk(KERN_ERR "NILFS: write access " "unavailable, cannot proceed.\n"); @@ -302,6 +313,11 @@ int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi) goto failed_unload; } sbi->s_super->s_flags &= ~MS_RDONLY; + } else if (nilfs_test_opt(sbi, NORECOVERY)) { + printk(KERN_ERR "NILFS: recovery cancelled because norecovery " + "option was specified for a read/write mount\n"); + err = -EINVAL; + goto failed_unload; } err = nilfs_recover_logical_segments(nilfs, sbi, &ri); diff --git a/include/linux/nilfs2_fs.h b/include/linux/nilfs2_fs.h index 72289d2bb341..3fe02cf8b65a 100644 --- a/include/linux/nilfs2_fs.h +++ b/include/linux/nilfs2_fs.h @@ -151,6 +151,8 @@ struct nilfs_super_root { #define NILFS_MOUNT_BARRIER 0x1000 /* Use block barriers */ #define NILFS_MOUNT_STRICT_ORDER 0x2000 /* Apply strict in-order semantics also for data */ +#define NILFS_MOUNT_NORECOVERY 0x4000 /* Disable write access during + mount-time recovery */ /** -- 2.39.5