ext4: check dioread_nolock on remount

Currently we allow enabling dioread_nolock mount option on remount for
filesystems where blocksize < PAGE_CACHE_SIZE.  This isn't really
supported so fix the bug by moving the check for blocksize !=
PAGE_CACHE_SIZE into parse_options(). Change the original PAGE_SIZE to
PAGE_CACHE_SIZE along the way because that's what we are really
interested in.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Cc: stable@vger.kernel.org

1 files changed, 11 insertions, 11 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 3cdb0a2fc648..e09f7d1646ba 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1645,9 +1645,7 @@ static int parse_options(char *options, struct super_block *sb,
                          unsigned int *journal_ioprio,
                          int is_remount)
 {
-#ifdef CONFIG_QUOTA
         struct ext4_sb_info *sbi = EXT4_SB(sb);
-#endif
         char *p;
         substring_t args[MAX_OPT_ARGS];
         int token;
@@ -1696,6 +1694,16 @@ static int parse_options(char *options, struct super_block *sb,
                 }
         }
 #endif
+        if (test_opt(sb, DIOREAD_NOLOCK)) {
+                int blocksize =
+                        BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
+
+                if (blocksize < PAGE_CACHE_SIZE) {
+                        ext4_msg(sb, KERN_ERR, "can't mount with "
+                                 "dioread_nolock if block size != PAGE_SIZE");
+                        return 0;
+                }
+        }
         return 1;
 }
 
@@ -3436,15 +3444,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
                         clear_opt(sb, DELALLOC);
         }
 
-        blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
-        if (test_opt(sb, DIOREAD_NOLOCK)) {
-                if (blocksize < PAGE_SIZE) {
-                        ext4_msg(sb, KERN_ERR, "can't mount with "
-                                 "dioread_nolock if block size != PAGE_SIZE");
-                        goto failed_mount;
-                }
-        }
-
         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
 
@@ -3486,6 +3485,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
                 goto failed_mount;
 
+        blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
             blocksize > EXT4_MAX_BLOCK_SIZE) {
                 ext4_msg(sb, KERN_ERR,