do-not-allow-journal_opts-for-fs-wo-journal

   1 ext4: do not allow journal_opts for fs w/o journal
   2
   3 From: Dmitry Monakhov <dmonakhov@openvz.org>
   4
   5 It is appeared that we can pass journal related mount options and such options
   6 be shown in /proc/mounts
   7
   8 Example:
   9 #mkfs.ext4 -F /dev/vdb
  10 #tune2fs -O ^has_journal /dev/vdb
  11 #mount /dev/vdb /mnt/  -ocommit=20,journal_async_commit
  12 #cat /proc/mounts  | grep /mnt
  13  /dev/vdb /mnt ext4 rw,relatime,journal_checksum,journal_async_commit,commit=20,data=ordered 0 0
  14
  15 But options:"journal_checksum,journal_async_commit,commit=20,data=ordered" has
  16 nothing with reality because there is no journal at all.
  17
  18 This patch disallow following options for journalless configurations:
  19  - journal_checksum
  20  - journal_async_commit
  21  - commit=%ld
  22  - data={writeback,ordered,journal}
  23
  24 Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
  25 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  26 Reviewed-by: Andreas Dilger <adilger@dilger.ca>
  27 ---
  28  fs/ext4/ext4.h  |    3 +++
  29  fs/ext4/super.c |   31 +++++++++++++++++++++++++++++--
  30  2 files changed, 32 insertions(+), 2 deletions(-)
  31
  32 diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
  33 index 3f248c9..871cdc6 100644
  34 --- a/fs/ext4/ext4.h
  35 +++ b/fs/ext4/ext4.h
  36 @@ -1019,6 +1019,9 @@ struct ext4_inode_info {
  37  #define EXT4_MOUNT2_HURD_COMPAT                0x00000004 /* Support HURD-castrated
  38                                                       file systems */
  39
  40 +#define EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM  0x00000008 /* User explicitly
  41 +                                               specified journal checksum */
  42 +
  43  #define clear_opt(sb, opt)             EXT4_SB(sb)->s_mount_opt &= \
  44                                                 ~EXT4_MOUNT_##opt
  45  #define set_opt(sb, opt)               EXT4_SB(sb)->s_mount_opt |= \
  46 diff --git a/fs/ext4/super.c b/fs/ext4/super.c
  47 index e91f6d4..a29b32b 100644
  48 --- a/fs/ext4/super.c
  49 +++ b/fs/ext4/super.c
  50 @@ -1371,10 +1371,10 @@ static const struct mount_opts {
  51         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
  52          MOPT_EXT4_ONLY | MOPT_CLEAR},
  53         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
  54 -        MOPT_EXT4_ONLY | MOPT_SET},
  55 +        MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
  56         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
  57                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
  58 -        MOPT_EXT4_ONLY | MOPT_SET},
  59 +        MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
  60         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
  61         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
  62         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
  63 @@ -1506,6 +1506,8 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
  64         if (m->flags & MOPT_EXPLICIT) {
  65                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
  66                         set_opt2(sb, EXPLICIT_DELALLOC);
  67 +               } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
  68 +                       set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
  69                 } else
  70                         return -1;
  71         }
  72 @@ -3675,6 +3677,31 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
  73                        "suppressed and not mounted read-only");
  74                 goto failed_mount_wq;
  75         } else {
  76 +               /* Nojournal mode, all journal mount options are illegal */
  77 +               if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
  78 +                       ext4_msg(sb, KERN_ERR, "can't mount with "
  79 +                                "journal_checksum, fs mounted w/o journal");
  80 +                       goto failed_mount_wq;
  81 +               }
  82 +               if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
  83 +                       ext4_msg(sb, KERN_ERR, "can't mount with "
  84 +                                "journal_async_commit, fs mounted w/o journal");
  85 +                       goto failed_mount_wq;
  86 +               }
  87 +               if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
  88 +                       ext4_msg(sb, KERN_ERR, "can't mount with "
  89 +                                "commit=%lu, fs mounted w/o journal",
  90 +                                sbi->s_commit_interval / HZ);
  91 +                       goto failed_mount_wq;
  92 +               }
  93 +               if (EXT4_MOUNT_DATA_FLAGS &
  94 +                   (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
  95 +                       ext4_msg(sb, KERN_ERR, "can't mount with "
  96 +                                "data=, fs mounted w/o journal");
  97 +                       goto failed_mount_wq;
  98 +               }
  99 +               sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
 100 +               clear_opt(sb, JOURNAL_CHECKSUM);
 101                 clear_opt(sb, DATA_FLAGS);
 102                 sbi->s_journal = NULL;
 103                 needs_recovery = 0;
 104 --
 105 1.7.1
 106
 107