diff options
author | Jan Kara <jack@suse.cz> | 2017-10-09 17:34:58 +0300 |
---|---|---|
committer | Jan Kara <jack@suse.cz> | 2017-10-11 12:43:24 +0300 |
commit | 088519572ca8bd6ab354d74bf7c88f413ed0e0be (patch) | |
tree | cbdc7505be12df22e71dd68bf87db1013e07a0f2 /fs | |
parent | de8cd83e91bc3ee212b3e6ec6e4283af9e4ab269 (diff) | |
download | linux-088519572ca8bd6ab354d74bf7c88f413ed0e0be.tar.xz |
ext2: Parse mount options into a dedicated structure
Instead of parsing mount options directly into the superblock (and
restoring options in case of error), parse the options into a dedicated
structure and only copy everything when we know we can safely switch
options. This will allow us to simplify locking and do option parsing
without holding sb->s_lock.
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/ext2/super.c | 157 |
1 files changed, 76 insertions, 81 deletions
diff --git a/fs/ext2/super.c b/fs/ext2/super.c index 1458706bd2ec..05eae20d133f 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -479,10 +479,10 @@ static const match_table_t tokens = { {Opt_err, NULL} }; -static int parse_options(char *options, struct super_block *sb) +static int parse_options(char *options, struct super_block *sb, + struct ext2_mount_options *opts) { char *p; - struct ext2_sb_info *sbi = EXT2_SB(sb); substring_t args[MAX_OPT_ARGS]; int option; kuid_t uid; @@ -499,16 +499,16 @@ static int parse_options(char *options, struct super_block *sb) token = match_token(p, tokens, args); switch (token) { case Opt_bsd_df: - clear_opt (sbi->s_mount_opt, MINIX_DF); + clear_opt (opts->s_mount_opt, MINIX_DF); break; case Opt_minix_df: - set_opt (sbi->s_mount_opt, MINIX_DF); + set_opt (opts->s_mount_opt, MINIX_DF); break; case Opt_grpid: - set_opt (sbi->s_mount_opt, GRPID); + set_opt (opts->s_mount_opt, GRPID); break; case Opt_nogrpid: - clear_opt (sbi->s_mount_opt, GRPID); + clear_opt (opts->s_mount_opt, GRPID); break; case Opt_resuid: if (match_int(&args[0], &option)) @@ -519,7 +519,7 @@ static int parse_options(char *options, struct super_block *sb) return 0; } - sbi->s_resuid = uid; + opts->s_resuid = uid; break; case Opt_resgid: if (match_int(&args[0], &option)) @@ -529,51 +529,51 @@ static int parse_options(char *options, struct super_block *sb) ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option); return 0; } - sbi->s_resgid = gid; + opts->s_resgid = gid; break; case Opt_sb: /* handled by get_sb_block() instead of here */ /* *sb_block = match_int(&args[0]); */ break; case Opt_err_panic: - clear_opt (sbi->s_mount_opt, ERRORS_CONT); - clear_opt (sbi->s_mount_opt, ERRORS_RO); - set_opt (sbi->s_mount_opt, ERRORS_PANIC); + clear_opt (opts->s_mount_opt, ERRORS_CONT); + clear_opt (opts->s_mount_opt, ERRORS_RO); + set_opt (opts->s_mount_opt, ERRORS_PANIC); break; case Opt_err_ro: - clear_opt (sbi->s_mount_opt, ERRORS_CONT); - clear_opt (sbi->s_mount_opt, ERRORS_PANIC); - set_opt (sbi->s_mount_opt, ERRORS_RO); + clear_opt (opts->s_mount_opt, ERRORS_CONT); + clear_opt (opts->s_mount_opt, ERRORS_PANIC); + set_opt (opts->s_mount_opt, ERRORS_RO); break; case Opt_err_cont: - clear_opt (sbi->s_mount_opt, ERRORS_RO); - clear_opt (sbi->s_mount_opt, ERRORS_PANIC); - set_opt (sbi->s_mount_opt, ERRORS_CONT); + clear_opt (opts->s_mount_opt, ERRORS_RO); + clear_opt (opts->s_mount_opt, ERRORS_PANIC); + set_opt (opts->s_mount_opt, ERRORS_CONT); break; case Opt_nouid32: - set_opt (sbi->s_mount_opt, NO_UID32); + set_opt (opts->s_mount_opt, NO_UID32); break; case Opt_nocheck: - clear_opt (sbi->s_mount_opt, CHECK); + clear_opt (opts->s_mount_opt, CHECK); break; case Opt_debug: - set_opt (sbi->s_mount_opt, DEBUG); + set_opt (opts->s_mount_opt, DEBUG); break; case Opt_oldalloc: - set_opt (sbi->s_mount_opt, OLDALLOC); + set_opt (opts->s_mount_opt, OLDALLOC); break; case Opt_orlov: - clear_opt (sbi->s_mount_opt, OLDALLOC); + clear_opt (opts->s_mount_opt, OLDALLOC); break; case Opt_nobh: - set_opt (sbi->s_mount_opt, NOBH); + set_opt (opts->s_mount_opt, NOBH); break; #ifdef CONFIG_EXT2_FS_XATTR case Opt_user_xattr: - set_opt (sbi->s_mount_opt, XATTR_USER); + set_opt (opts->s_mount_opt, XATTR_USER); break; case Opt_nouser_xattr: - clear_opt (sbi->s_mount_opt, XATTR_USER); + clear_opt (opts->s_mount_opt, XATTR_USER); break; #else case Opt_user_xattr: @@ -584,10 +584,10 @@ static int parse_options(char *options, struct super_block *sb) #endif #ifdef CONFIG_EXT2_FS_POSIX_ACL case Opt_acl: - set_opt(sbi->s_mount_opt, POSIX_ACL); + set_opt(opts->s_mount_opt, POSIX_ACL); break; case Opt_noacl: - clear_opt(sbi->s_mount_opt, POSIX_ACL); + clear_opt(opts->s_mount_opt, POSIX_ACL); break; #else case Opt_acl: @@ -598,13 +598,13 @@ static int parse_options(char *options, struct super_block *sb) #endif case Opt_xip: ext2_msg(sb, KERN_INFO, "use dax instead of xip"); - set_opt(sbi->s_mount_opt, XIP); + set_opt(opts->s_mount_opt, XIP); /* Fall through */ case Opt_dax: #ifdef CONFIG_FS_DAX ext2_msg(sb, KERN_WARNING, "DAX enabled. Warning: EXPERIMENTAL, use at your own risk"); - set_opt(sbi->s_mount_opt, DAX); + set_opt(opts->s_mount_opt, DAX); #else ext2_msg(sb, KERN_INFO, "dax option not supported"); #endif @@ -613,11 +613,11 @@ static int parse_options(char *options, struct super_block *sb) #if defined(CONFIG_QUOTA) case Opt_quota: case Opt_usrquota: - set_opt(sbi->s_mount_opt, USRQUOTA); + set_opt(opts->s_mount_opt, USRQUOTA); break; case Opt_grpquota: - set_opt(sbi->s_mount_opt, GRPQUOTA); + set_opt(opts->s_mount_opt, GRPQUOTA); break; #else case Opt_quota: @@ -629,11 +629,11 @@ static int parse_options(char *options, struct super_block *sb) #endif case Opt_reservation: - set_opt(sbi->s_mount_opt, RESERVATION); + set_opt(opts->s_mount_opt, RESERVATION); ext2_msg(sb, KERN_INFO, "reservations ON"); break; case Opt_noreservation: - clear_opt(sbi->s_mount_opt, RESERVATION); + clear_opt(opts->s_mount_opt, RESERVATION); ext2_msg(sb, KERN_INFO, "reservations OFF"); break; case Opt_ignore: @@ -830,6 +830,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent) int i, j; __le32 features; int err; + struct ext2_mount_options opts; err = -ENOMEM; sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); @@ -890,35 +891,39 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent) /* Set defaults before we parse the mount options */ def_mount_opts = le32_to_cpu(es->s_default_mount_opts); if (def_mount_opts & EXT2_DEFM_DEBUG) - set_opt(sbi->s_mount_opt, DEBUG); + set_opt(opts.s_mount_opt, DEBUG); if (def_mount_opts & EXT2_DEFM_BSDGROUPS) - set_opt(sbi->s_mount_opt, GRPID); + set_opt(opts.s_mount_opt, GRPID); if (def_mount_opts & EXT2_DEFM_UID16) - set_opt(sbi->s_mount_opt, NO_UID32); + set_opt(opts.s_mount_opt, NO_UID32); #ifdef CONFIG_EXT2_FS_XATTR if (def_mount_opts & EXT2_DEFM_XATTR_USER) - set_opt(sbi->s_mount_opt, XATTR_USER); + set_opt(opts.s_mount_opt, XATTR_USER); #endif #ifdef CONFIG_EXT2_FS_POSIX_ACL if (def_mount_opts & EXT2_DEFM_ACL) - set_opt(sbi->s_mount_opt, POSIX_ACL); + set_opt(opts.s_mount_opt, POSIX_ACL); #endif if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC) - set_opt(sbi->s_mount_opt, ERRORS_PANIC); + set_opt(opts.s_mount_opt, ERRORS_PANIC); else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE) - set_opt(sbi->s_mount_opt, ERRORS_CONT); + set_opt(opts.s_mount_opt, ERRORS_CONT); else - set_opt(sbi->s_mount_opt, ERRORS_RO); + set_opt(opts.s_mount_opt, ERRORS_RO); - sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid)); - sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid)); + opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid)); + opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid)); - set_opt(sbi->s_mount_opt, RESERVATION); + set_opt(opts.s_mount_opt, RESERVATION); - if (!parse_options((char *) data, sb)) + if (!parse_options((char *) data, sb, &opts)) goto failed_mount; + sbi->s_mount_opt = opts.s_mount_opt; + sbi->s_resuid = opts.s_resuid; + sbi->s_resgid = opts.s_resgid; + sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); @@ -1312,46 +1317,36 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data) { struct ext2_sb_info * sbi = EXT2_SB(sb); struct ext2_super_block * es; - struct ext2_mount_options old_opts; - unsigned long old_sb_flags; + struct ext2_mount_options new_opts; int err; sync_filesystem(sb); spin_lock(&sbi->s_lock); - /* Store the old options */ - old_sb_flags = sb->s_flags; - old_opts.s_mount_opt = sbi->s_mount_opt; - old_opts.s_resuid = sbi->s_resuid; - old_opts.s_resgid = sbi->s_resgid; + new_opts.s_mount_opt = sbi->s_mount_opt; + new_opts.s_resuid = sbi->s_resuid; + new_opts.s_resgid = sbi->s_resgid; /* * Allow the "check" option to be passed as a remount option. */ - if (!parse_options(data, sb)) { - err = -EINVAL; - goto restore_opts; + if (!parse_options(data, sb, &new_opts)) { + spin_unlock(&sbi->s_lock); + return -EINVAL; } - sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | - ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); - es = sbi->s_es; - if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT2_MOUNT_DAX) { + if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) { ext2_msg(sb, KERN_WARNING, "warning: refusing change of " "dax flag with busy inodes while remounting"); - sbi->s_mount_opt ^= EXT2_MOUNT_DAX; - } - if ((bool)(*flags & MS_RDONLY) == sb_rdonly(sb)) { - spin_unlock(&sbi->s_lock); - return 0; + new_opts.s_mount_opt ^= EXT2_MOUNT_DAX; } + if ((bool)(*flags & MS_RDONLY) == sb_rdonly(sb)) + goto out_set; if (*flags & MS_RDONLY) { if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || - !(sbi->s_mount_state & EXT2_VALID_FS)) { - spin_unlock(&sbi->s_lock); - return 0; - } + !(sbi->s_mount_state & EXT2_VALID_FS)) + goto out_set; /* * OK, we are remounting a valid rw partition rdonly, so set @@ -1362,22 +1357,20 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data) spin_unlock(&sbi->s_lock); err = dquot_suspend(sb, -1); - if (err < 0) { - spin_lock(&sbi->s_lock); - goto restore_opts; - } + if (err < 0) + return err; ext2_sync_super(sb, es, 1); } else { __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP); if (ret) { + spin_unlock(&sbi->s_lock); ext2_msg(sb, KERN_WARNING, "warning: couldn't remount RDWR because of " "unsupported optional features (%x).", le32_to_cpu(ret)); - err = -EROFS; - goto restore_opts; + return -EROFS; } /* * Mounting a RDONLY partition read-write, so reread and @@ -1394,14 +1387,16 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data) dquot_resume(sb, -1); } - return 0; -restore_opts: - sbi->s_mount_opt = old_opts.s_mount_opt; - sbi->s_resuid = old_opts.s_resuid; - sbi->s_resgid = old_opts.s_resgid; - sb->s_flags = old_sb_flags; + spin_lock(&sbi->s_lock); +out_set: + sbi->s_mount_opt = new_opts.s_mount_opt; + sbi->s_resuid = new_opts.s_resuid; + sbi->s_resgid = new_opts.s_resgid; + sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | + ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); spin_unlock(&sbi->s_lock); - return err; + + return 0; } static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) |