[RESEND PATCH 1/3] btrfs: wrap rdonly check into btrfs_fs_is_rdonly

[Anand Jain <anand.jain@oracle.com>]

As of now, the BTRFS_FS_OPEN flag is true if the filesystem open is complete
and as well as it is used for the affirmation if the filesystem read-write
able.

In preparatory to take out the rw affirm part in the above flag, first
consolidate the check for filesystem rdonly into the function
btrfs_fs_is_rdonly(). It makes migration to the new definition of the
flag BTRFS_FS_OPEN cleaner.

Here I introduce a new function btrfs_fs_is_rdonly(), it consolidates the
current two ways we check for the filesystem in rdonly.

At all places we use the check
   sb_rdonly(fs_info->sb)
however in the funtion btrfs_need_cleaner_sleep() we use the
   test_bit(BTRFS_FS_STATE_RO....).

As per the comment of btrfs_need_cleaner_sleep(), it needs to use
BTRFS_FS_STATE_RO state for the atomicity purpose.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
Change log reworded.
The same patch was marked as RFC before. To know if there is any better way to 
clean up. Now I think there isn't. Removed 

 fs/btrfs/block-group.c  |  2 +-
 fs/btrfs/ctree.h        | 13 +++++++++++--
 fs/btrfs/dev-replace.c  |  2 +-
 fs/btrfs/disk-io.c      | 11 ++++++-----
 fs/btrfs/extent_io.c    |  4 ++--
 fs/btrfs/inode.c        |  2 +-
 fs/btrfs/ioctl.c        |  2 +-
 fs/btrfs/super.c        | 12 ++++++------
 fs/btrfs/sysfs.c        |  4 ++--
 fs/btrfs/tree-checker.c |  2 +-
 fs/btrfs/volumes.c      |  4 ++--
 11 files changed, 34 insertions(+), 24 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index ede389f2602d..8f73dc120290 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -2597,7 +2597,7 @@ int btrfs_inc_block_group_ro(struct btrfs_block_group *cache,
 	 * In that case we should not start a new transaction on read-only fs.
 	 * Thus here we skip all chunk allocations.
 	 */
-	if (sb_rdonly(fs_info->sb)) {
+	if (btrfs_fs_is_rdonly(fs_info)) {
 		mutex_lock(&fs_info->ro_block_group_mutex);
 		ret = inc_block_group_ro(cache, 0);
 		mutex_unlock(&fs_info->ro_block_group_mutex);
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 777d0b1a0b1e..171dd25def8b 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3119,6 +3119,16 @@ static inline int btrfs_fs_closing(struct btrfs_fs_info *fs_info)
 	return 0;
 }
 
+static inline bool btrfs_fs_is_rdonly(const struct btrfs_fs_info *fs_info)
+{
+	bool rdonly = sb_rdonly(fs_info->sb);
+	bool fs_rdonly = test_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state);
+
+	BUG_ON(rdonly != fs_rdonly);
+
+	return rdonly;
+}
+
 /*
  * If we remount the fs to be R/O or umount the fs, the cleaner needn't do
  * anything except sleeping. This function is used to check the status of
@@ -3129,8 +3139,7 @@ static inline int btrfs_fs_closing(struct btrfs_fs_info *fs_info)
  */
 static inline int btrfs_need_cleaner_sleep(struct btrfs_fs_info *fs_info)
 {
-	return test_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state) ||
-		btrfs_fs_closing(fs_info);
+	return btrfs_fs_is_rdonly(fs_info) || btrfs_fs_closing(fs_info);
 }
 
 static inline void btrfs_set_sb_rdonly(struct super_block *sb)
diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index ee92854b3a49..0790e0e49a78 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -1082,7 +1082,7 @@ int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
 	int result;
 	int ret;
 
-	if (sb_rdonly(fs_info->sb))
+	if (btrfs_fs_is_rdonly(fs_info))
 		return -EROFS;
 
 	mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 5a39e63c7aa4..624070f144d0 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2570,7 +2570,7 @@ static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
 		return ret;
 	}
 
-	if (sb_rdonly(fs_info->sb)) {
+	if (btrfs_fs_is_rdonly(fs_info)) {
 		ret = btrfs_commit_super(fs_info);
 		if (ret)
 			return ret;
@@ -3648,7 +3648,7 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 
 	features = btrfs_super_compat_ro_flags(disk_super) &
 		~BTRFS_FEATURE_COMPAT_RO_SUPP;
-	if (!sb_rdonly(sb) && features) {
+	if (!btrfs_fs_is_rdonly(fs_info) && features) {
 		btrfs_err(fs_info,
 	"cannot mount read-write because of unsupported optional features (0x%llx)",
 		       features);
@@ -3823,7 +3823,8 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 
 	btrfs_free_zone_cache(fs_info);
 
-	if (!sb_rdonly(sb) && fs_info->fs_devices->missing_devices &&
+	if (!btrfs_fs_is_rdonly(fs_info) &&
+	    fs_info->fs_devices->missing_devices &&
 	    !btrfs_check_rw_degradable(fs_info, NULL)) {
 		btrfs_warn(fs_info,
 		"writable mount is not allowed due to too many missing devices");
@@ -3890,7 +3891,7 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 		goto fail_qgroup;
 	}
 
-	if (sb_rdonly(sb))
+	if (btrfs_fs_is_rdonly(fs_info))
 		goto clear_oneshot;
 
 	ret = btrfs_start_pre_rw_mount(fs_info);
@@ -4687,7 +4688,7 @@ void __cold close_ctree(struct btrfs_fs_info *fs_info)
 	/* Cancel or finish ongoing discard work */
 	btrfs_discard_cleanup(fs_info);
 
-	if (!sb_rdonly(fs_info->sb)) {
+	if (!btrfs_fs_is_rdonly(fs_info)) {
 		/*
 		 * The cleaner kthread is stopped, so do one final pass over
 		 * unused block groups.
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 4847e0471dbf..70283ebcc3c4 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2402,7 +2402,7 @@ int btrfs_repair_eb_io_failure(const struct extent_buffer *eb, int mirror_num)
 	int i, num_pages = num_extent_pages(eb);
 	int ret = 0;
 
-	if (sb_rdonly(fs_info->sb))
+	if (btrfs_fs_is_rdonly(fs_info))
 		return -EROFS;
 
 	for (i = 0; i < num_pages; i++) {
@@ -2445,7 +2445,7 @@ int clean_io_failure(struct btrfs_fs_info *fs_info,
 
 	BUG_ON(!failrec->this_mirror);
 
-	if (sb_rdonly(fs_info->sb))
+	if (btrfs_fs_is_rdonly(fs_info))
 		goto out;
 
 	spin_lock(&io_tree->lock);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index bb1677f6f201..809aa9d31bb3 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5785,7 +5785,7 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
 
 	if (!IS_ERR(inode) && root != sub_root) {
 		down_read(&fs_info->cleanup_work_sem);
-		if (!sb_rdonly(inode->i_sb))
+		if (!btrfs_fs_is_rdonly(fs_info))
 			ret = btrfs_orphan_cleanup(sub_root);
 		up_read(&fs_info->cleanup_work_sem);
 		if (ret) {
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 840a7d95ab86..8acf54d1962a 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4152,7 +4152,7 @@ static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
 
 	switch (p->cmd) {
 	case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
-		if (sb_rdonly(fs_info->sb)) {
+		if (btrfs_fs_is_rdonly(fs_info)) {
 			ret = -EROFS;
 			goto out;
 		}
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 4d43895504b7..9ace5ac8a688 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -183,7 +183,7 @@ void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function
 	 * Special case: if the error is EROFS, and we're already
 	 * under SB_RDONLY, then it is safe here.
 	 */
-	if (errno == -EROFS && sb_rdonly(sb))
+	if (errno == -EROFS && btrfs_fs_is_rdonly(fs_info))
   		return;
 
 #ifdef CONFIG_PRINTK
@@ -216,7 +216,7 @@ void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function
 	if (!(sb->s_flags & SB_BORN))
 		return;
 
-	if (sb_rdonly(sb))
+	if (btrfs_fs_is_rdonly(fs_info))
 		return;
 
 	btrfs_discard_stop(fs_info);
@@ -1940,9 +1940,9 @@ static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
 	 * close or the filesystem is read only.
 	 */
 	if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
-	    (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || sb_rdonly(fs_info->sb))) {
+	    (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
+	     btrfs_fs_is_rdonly(fs_info)))
 		btrfs_cleanup_defrag_inodes(fs_info);
-	}
 
 	/* If we toggled discard async */
 	if (!btrfs_raw_test_opt(old_opts, DISCARD_ASYNC) &&
@@ -2000,7 +2000,7 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
 
 	if ((bool)btrfs_test_opt(fs_info, FREE_SPACE_TREE) !=
 	    (bool)btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
-	    (!sb_rdonly(sb) || (*flags & SB_RDONLY))) {
+	    (!btrfs_fs_is_rdonly(fs_info) || (*flags & SB_RDONLY))) {
 		btrfs_warn(fs_info,
 		"remount supports changing free space tree only from ro to rw");
 		/* Make sure free space cache options match the state on disk */
@@ -2014,7 +2014,7 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
 		}
 	}
 
-	if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
+	if ((bool)(*flags & SB_RDONLY) == btrfs_fs_is_rdonly(fs_info))
 		goto out;
 
 	if (*flags & SB_RDONLY) {
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index ebe76d7a4a64..857600537c3b 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -200,7 +200,7 @@ static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 	if (!fs_info)
 		return -EPERM;
 
-	if (sb_rdonly(fs_info->sb))
+	if (btrfs_fs_is_rdonly(fs_info))
 		return -EROFS;
 
 	ret = kstrtoul(skip_spaces(buf), 0, &val);
@@ -942,7 +942,7 @@ static ssize_t btrfs_label_store(struct kobject *kobj,
 	if (!fs_info)
 		return -EPERM;
 
-	if (sb_rdonly(fs_info->sb))
+	if (btrfs_fs_is_rdonly(fs_info))
 		return -EROFS;
 
 	/*
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
index 9e0e0ae2288c..24aa0e00bf5a 100644
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -1104,7 +1104,7 @@ static int check_inode_item(struct extent_buffer *leaf,
 			       "unknown incompat flags detected: 0x%x", flags);
 		return -EUCLEAN;
 	}
-	if (unlikely(!sb_rdonly(fs_info->sb) &&
+	if (unlikely(!btrfs_fs_is_rdonly(fs_info) &&
 		     (ro_flags & ~BTRFS_INODE_RO_FLAG_MASK))) {
 		inode_item_err(leaf, slot,
 			"unknown ro-compat flags detected on writeable mount: 0x%x",
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 982a2417d5bb..35b6b87464f7 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2630,7 +2630,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
 	bool seeding_dev = false;
 	bool locked = false;
 
-	if (sb_rdonly(sb) && !fs_devices->seeding)
+	if (btrfs_fs_is_rdonly(fs_info) && !fs_devices->seeding)
 		return -EROFS;
 
 	bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
@@ -4616,7 +4616,7 @@ int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
 	 * mount time if the mount is read-write. Otherwise it's still paused
 	 * and we must not allow cancelling as it deletes the item.
 	 */
-	if (sb_rdonly(fs_info->sb)) {
+	if (btrfs_fs_is_rdonly(fs_info)) {
 		mutex_unlock(&fs_info->balance_mutex);
 		return -EROFS;
 	}
-- 
2.33.1