ext4: fix the mount option "init_itable=n" to work as expected for n=0

For some reason, when we set the mount option "init_itable=0" it
behaves as we would set init_itable=20 which is not right at all.
Basically when we set it to zero we are saying to lazyinit thread not
to wait between zeroing the inode table (except of cond_resched()) so
this commit fixes that and removes the unnecessary condition.  The 'n'
should be also properly used on remount.

When the n is not set at all, it means that the default miltiplier
EXT4_DEF_LI_WAIT_MULT is set instead.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reported-by: Eric Sandeen <sandeen@redhat.com>

1 files changed, 16 insertions, 7 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index d7756bd2dc12..fd51a4a266b6 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1112,7 +1112,7 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 
         if (!test_opt(sb, INIT_INODE_TABLE))
                 seq_puts(seq, ",noinit_inode_table");
-        else if (sbi->s_li_wait_mult)
+        else if (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)
                 seq_printf(seq, ",init_inode_table=%u",
                            (unsigned) sbi->s_li_wait_mult);
 
@@ -2704,11 +2704,8 @@ static int ext4_run_li_request(struct ext4_li_request *elr)
                 ret = ext4_init_inode_table(sb, group,
                                             elr->lr_timeout ? 0 : 1);
                 if (elr->lr_timeout == 0) {
-                        timeout = jiffies - timeout;
-                        if (elr->lr_sbi->s_li_wait_mult)
-                                timeout *= elr->lr_sbi->s_li_wait_mult;
-                        else
-                                timeout *= 20;
+                        timeout = (jiffies - timeout) *
+                                  elr->lr_sbi->s_li_wait_mult;
                         elr->lr_timeout = timeout;
                 }
                 elr->lr_next_sched = jiffies + elr->lr_timeout;
@@ -2945,8 +2942,14 @@ static int ext4_register_li_request(struct super_block *sb,
         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
         int ret = 0;
 
-        if (sbi->s_li_request != NULL)
+        if (sbi->s_li_request != NULL) {
+                /*
+                 * Reset timeout so it can be computed again, because
+                 * s_li_wait_mult might have changed.
+                 */
+                sbi->s_li_request->lr_timeout = 0;
                 return 0;
+        }
 
         if (first_not_zeroed == ngroups ||
             (sb->s_flags & MS_RDONLY) ||
@@ -3144,6 +3147,12 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
                 set_opt(sb, DELALLOC);
 
+        /*
+         * set default s_li_wait_mult for lazyinit, for the case there is
+         * no mount option specified.
+         */
+        sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
+
         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
                            &journal_devnum, &journal_ioprio, NULL, 0)) {
                 ext4_msg(sb, KERN_WARNING,