ext4: fix races between page faults and hole punching

[firefly-linux-kernel-4.4.55.git] / fs / ext4 / super.c

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index c9ab67da6e5abbe871ce4bc7760c007e07f2b479..852c26806af275a1f3894c0a990c341540f23c06 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -958,6 +958,7 @@ static void init_once(void *foo)
        INIT_LIST_HEAD(&ei->i_orphan);
        init_rwsem(&ei->xattr_sem);
        init_rwsem(&ei->i_data_sem);
+       init_rwsem(&ei->i_mmap_sem);
        inode_init_once(&ei->vfs_inode);
 }
 
@@ -1292,9 +1293,9 @@ static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
                return -1;
        }
        if (ext4_has_feature_quota(sb)) {
-               ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
-                        "when QUOTA feature is enabled");
-               return -1;
+               ext4_msg(sb, KERN_INFO, "Journaled quota options "
+                        "ignored when QUOTA feature is enabled");
+               return 1;
        }
        qname = match_strdup(args);
        if (!qname) {
@@ -1657,10 +1658,10 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
                        return -1;
                }
                if (ext4_has_feature_quota(sb)) {
-                       ext4_msg(sb, KERN_ERR,
-                                "Cannot set journaled quota options "
+                       ext4_msg(sb, KERN_INFO,
+                                "Quota format mount options ignored "
                                 "when QUOTA feature is enabled");
-                       return -1;
+                       return 1;
                }
                sbi->s_jquota_fmt = m->mount_opt;
 #endif
@@ -1721,11 +1722,11 @@ static int parse_options(char *options, struct super_block *sb,
 #ifdef CONFIG_QUOTA
        if (ext4_has_feature_quota(sb) &&
            (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
-               ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
-                        "feature is enabled");
-               return 0;
-       }
-       if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
+               ext4_msg(sb, KERN_INFO, "Quota feature enabled, usrquota and grpquota "
+                        "mount options ignored.");
+               clear_opt(sb, USRQUOTA);
+               clear_opt(sb, GRPQUOTA);
+       } else if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
                if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
                        clear_opt(sb, USRQUOTA);
 
@@ -4936,6 +4937,20 @@ static int ext4_quota_on_mount(struct super_block *sb, int type)
                                        EXT4_SB(sb)->s_jquota_fmt, type);
 }
 
+static void lockdep_set_quota_inode(struct inode *inode, int subclass)
+{
+       struct ext4_inode_info *ei = EXT4_I(inode);
+
+       /* The first argument of lockdep_set_subclass has to be
+        * *exactly* the same as the argument to init_rwsem() --- in
+        * this case, in init_once() --- or lockdep gets unhappy
+        * because the name of the lock is set using the
+        * stringification of the argument to init_rwsem().
+        */
+       (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
+       lockdep_set_subclass(&ei->i_data_sem, subclass);
+}
+
 /*
  * Standard function to be called on quota_on
  */
@@ -4975,8 +4990,12 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id,
                if (err)
                        return err;
        }
-
-       return dquot_quota_on(sb, type, format_id, path);
+       lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
+       err = dquot_quota_on(sb, type, format_id, path);
+       if (err)
+               lockdep_set_quota_inode(path->dentry->d_inode,
+                                            I_DATA_SEM_NORMAL);
+       return err;
 }
 
 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
@@ -5002,8 +5021,11 @@ static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
 
        /* Don't account quota for quota files to avoid recursion */
        qf_inode->i_flags |= S_NOQUOTA;
+       lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
        err = dquot_enable(qf_inode, type, format_id, flags);
        iput(qf_inode);
+       if (err)
+               lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
 
        return err;
 }