ext4: correct mount option parsing to detect when quota options can be changed From: Jan Kara We should not allow user to change quota mount options when quota is just suspended. It would make mount options and internal quota state inconsistent. Also we should not allow user to change quota format when quota is turned on. On the other hand we can just silently ignore when some option is set to the value it already has (mount does this on remount). Cc: Signed-off-by: Jan Kara Signed-off-by: Andrew Morton Signed-off-by: Mingming Cao Signed-off-by: "Theodore Ts'o" --- fs/ext4/super.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) Index: linux-2.6.26-rc1/fs/ext4/super.c =================================================================== --- linux-2.6.26-rc1.orig/fs/ext4/super.c 2008-05-05 17:10:11.000000000 -0700 +++ linux-2.6.26-rc1/fs/ext4/super.c 2008-05-05 17:10:11.000000000 -0700 @@ -979,7 +979,7 @@ static int parse_options (char *options, int data_opt = 0; int option; #ifdef CONFIG_QUOTA - int qtype; + int qtype, qfmt; char *qname; #endif @@ -1162,7 +1162,9 @@ static int parse_options (char *options, case Opt_grpjquota: qtype = GRPQUOTA; set_qf_name: - if (sb_any_quota_enabled(sb)) { + if ((sb_any_quota_enabled(sb) || + sb_any_quota_suspended(sb)) && + !sbi->s_qf_names[qtype]) { printk(KERN_ERR "EXT4-fs: Cannot change journalled " "quota options when quota turned on.\n"); @@ -1200,7 +1202,9 @@ set_qf_name: case Opt_offgrpjquota: qtype = GRPQUOTA; clear_qf_name: - if (sb_any_quota_enabled(sb)) { + if ((sb_any_quota_enabled(sb) || + sb_any_quota_suspended(sb)) && + sbi->s_qf_names[qtype]) { printk(KERN_ERR "EXT4-fs: Cannot change " "journalled quota options when " "quota turned on.\n"); @@ -1213,10 +1217,20 @@ clear_qf_name: sbi->s_qf_names[qtype] = NULL; break; case Opt_jqfmt_vfsold: - sbi->s_jquota_fmt = QFMT_VFS_OLD; - break; + qfmt = QFMT_VFS_OLD; + goto set_qf_format; case Opt_jqfmt_vfsv0: - sbi->s_jquota_fmt = QFMT_VFS_V0; + qfmt = QFMT_VFS_V0; +set_qf_format: + if ((sb_any_quota_enabled(sb) || + sb_any_quota_suspended(sb)) && + sbi->s_jquota_fmt != qfmt) { + printk(KERN_ERR "EXT4-fs: Cannot change " + "journaled quota options when " + "quota turned on.\n"); + return 0; + } + sbi->s_jquota_fmt = qfmt; break; case Opt_quota: case Opt_usrquota: