ext4: Remove "extents" mount option

This mount option is largely superfluous, and in fact the way it was
implemented was buggy; if a filesystem which did not have the extents
feature flag was mounted -o extents, the filesystem would attempt to
create and use extents-based file even though the extents feature flag
was not eabled.  The simplest thing to do is to nuke the mount option
entirely.  It's not all that useful to force the non-creation of new
extent-based files if the filesystem can support it.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 2 insertions, 46 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index b69d09203865..acb69c00fd42 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -829,8 +829,6 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
                 seq_puts(seq, ",journal_async_commit");
         if (test_opt(sb, NOBH))
                 seq_puts(seq, ",nobh");
-        if (!test_opt(sb, EXTENTS))
-                seq_puts(seq, ",noextents");
         if (test_opt(sb, I_VERSION))
                 seq_puts(seq, ",i_version");
         if (!test_opt(sb, DELALLOC))
@@ -1011,7 +1009,7 @@ enum {
         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
-        Opt_grpquota, Opt_extents, Opt_noextents, Opt_i_version,
+        Opt_grpquota, Opt_i_version,
         Opt_stripe, Opt_delalloc, Opt_nodelalloc,
         Opt_inode_readahead_blks, Opt_journal_ioprio
 };
@@ -1066,8 +1064,6 @@ static const match_table_t tokens = {
         {Opt_quota, "quota"},
         {Opt_usrquota, "usrquota"},
         {Opt_barrier, "barrier=%u"},
-        {Opt_extents, "extents"},
-        {Opt_noextents, "noextents"},
         {Opt_i_version, "i_version"},
         {Opt_stripe, "stripe=%u"},
         {Opt_resize, "resize"},
@@ -1115,7 +1111,6 @@ static int parse_options(char *options, struct super_block *sb,
         int qtype, qfmt;
         char *qname;
 #endif
-        ext4_fsblk_t last_block;
 
         if (!options)
                 return 1;
@@ -1445,33 +1440,6 @@ set_qf_format:
                 case Opt_bh:
                         clear_opt(sbi->s_mount_opt, NOBH);
                         break;
-                case Opt_extents:
-                        if (!EXT4_HAS_INCOMPAT_FEATURE(sb,
-                                        EXT4_FEATURE_INCOMPAT_EXTENTS)) {
-                                ext4_warning(sb, __func__,
-                                        "extents feature not enabled "
-                                        "on this filesystem, use tune2fs");
-                                return 0;
-                        }
-                        set_opt(sbi->s_mount_opt, EXTENTS);
-                        break;
-                case Opt_noextents:
-                        /*
-                         * When e2fsprogs support resizing an already existing
-                         * ext3 file system to greater than 2**32 we need to
-                         * add support to block allocator to handle growing
-                         * already existing block  mapped inode so that blocks
-                         * allocated for them fall within 2**32
-                         */
-                        last_block = ext4_blocks_count(sbi->s_es) - 1;
-                        if (last_block  > 0xffffffffULL) {
-                                printk(KERN_ERR "EXT4-fs: Filesystem too "
-                                                "large to mount with "
-                                                "-o noextents options\n");
-                                return 0;
-                        }
-                        clear_opt(sbi->s_mount_opt, EXTENTS);
-                        break;
                 case Opt_i_version:
                         set_opt(sbi->s_mount_opt, I_VERSION);
                         sb->s_flags |= MS_I_VERSION;
@@ -2136,18 +2104,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
         set_opt(sbi->s_mount_opt, BARRIER);
 
         /*
-         * turn on extents feature by default in ext4 filesystem
-         * only if feature flag already set by mkfs or tune2fs.
-         * Use -o noextents to turn it off
-         */
-        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
-                set_opt(sbi->s_mount_opt, EXTENTS);
-        else
-                ext4_warning(sb, __func__,
-                        "extents feature not enabled on this filesystem, "
-                        "use tune2fs.");
-
-        /*
          * enable delayed allocation by default
          * Use -o nodelalloc to turn it off
          */
@@ -3825,7 +3781,7 @@ static void __exit exit_ext4_fs(void)
 }
 
 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
-MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
+MODULE_DESCRIPTION("Fourth Extended Filesystem");
 MODULE_LICENSE("GPL");
 module_init(init_ext4_fs)
 module_exit(exit_ext4_fs)