[PATCH v2 12/34] hfs: use the generic emergency read-only state

[Christian Brauner <brauner@kernel.org>]

Set SB_STATE_EMERGENCY_RO instead of a private bit and drop the checks
the VFS does now. What's left is hfs_get_block(), hfs_file_truncate(),
write_begin, O_DIRECT writes, the hfs.type and hfs.creator xattrs,
hfs_write_inode() which still writes the b-tree headers, and the MDB
commit, close and dirtying paths.

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
---
 fs/hfs/attr.c   |  2 +-
 fs/hfs/dir.c    | 12 ------------
 fs/hfs/extent.c |  4 ++--
 fs/hfs/hfs_fs.h | 11 -----------
 fs/hfs/inode.c  | 20 ++++----------------
 fs/hfs/mdb.c    |  8 ++++----
 fs/hfs/super.c  |  5 +----
 7 files changed, 12 insertions(+), 50 deletions(-)

diff --git a/fs/hfs/attr.c b/fs/hfs/attr.c
index bd9a1289d8c5..337b22f28208 100644
--- a/fs/hfs/attr.c
+++ b/fs/hfs/attr.c
@@ -129,7 +129,7 @@ static int hfs_xattr_set(const struct xattr_handler *handler,
 	if (!value)
 		return -EOPNOTSUPP;
 
-	if (unlikely(hfs_emergency_ro(inode->i_sb)))
+	if (unlikely(sb_emergency_ro(inode->i_sb)))
 		return -EROFS;
 
 	return __hfs_setxattr(inode, handler->flags, value, size, flags);
diff --git a/fs/hfs/dir.c b/fs/hfs/dir.c
index f0d8ddb07503..f6b97da19788 100644
--- a/fs/hfs/dir.c
+++ b/fs/hfs/dir.c
@@ -189,9 +189,6 @@ static int hfs_create(const struct mnt_idmap *idmap, struct inode *dir,
 	struct inode *inode;
 	int res;
 
-	if (unlikely(hfs_emergency_ro(dir->i_sb)))
-		return -EROFS;
-
 	inode = hfs_new_inode(dir, &dentry->d_name, mode);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);
@@ -222,9 +219,6 @@ static struct dentry *hfs_mkdir(const struct mnt_idmap *idmap, struct inode *dir
 	struct inode *inode;
 	int res;
 
-	if (unlikely(hfs_emergency_ro(dir->i_sb)))
-		return ERR_PTR(-EROFS);
-
 	inode = hfs_new_inode(dir, &dentry->d_name, mode);
 	if (IS_ERR(inode))
 		return ERR_CAST(inode);
@@ -258,9 +252,6 @@ static int hfs_remove(struct inode *dir, struct dentry *dentry)
 	struct inode *inode = d_inode(dentry);
 	int res;
 
-	if (unlikely(hfs_emergency_ro(sb)))
-		return -EROFS;
-
 	if (S_ISDIR(inode->i_mode) && inode->i_size != 2)
 		return -ENOTEMPTY;
 
@@ -299,9 +290,6 @@ static int hfs_rename(const struct mnt_idmap *idmap, struct inode *old_dir,
 	if (flags & ~RENAME_NOREPLACE)
 		return -EINVAL;
 
-	if (unlikely(hfs_emergency_ro(old_dir->i_sb)))
-		return -EROFS;
-
 	/* Unlink destination if it already exists */
 	if (d_really_is_positive(new_dentry)) {
 		res = hfs_remove(new_dir, new_dentry);
diff --git a/fs/hfs/extent.c b/fs/hfs/extent.c
index dacf7ce1ffe4..fd874a93a92f 100644
--- a/fs/hfs/extent.c
+++ b/fs/hfs/extent.c
@@ -357,7 +357,7 @@ int hfs_get_block(struct inode *inode, sector_t block,
 			return -EIO;
 		if (ablock >= HFS_I(inode)->alloc_blocks) {
 			/* No new allocations after an error. */
-			if (unlikely(hfs_emergency_ro(sb)))
+			if (unlikely(sb_emergency_ro(sb)))
 				return -EROFS;
 			res = hfs_extend_file(inode);
 			if (res)
@@ -494,7 +494,7 @@ void hfs_file_truncate(struct inode *inode)
 	hfs_dbg("ino %llu, phys_size %llu -> i_size %llu\n",
 		inode->i_ino, (long long)HFS_I(inode)->phys_size,
 		inode->i_size);
-	if (unlikely(hfs_emergency_ro(sb)))
+	if (unlikely(sb_emergency_ro(sb)))
 		return;
 	if (inode->i_size > HFS_I(inode)->phys_size) {
 		struct address_space *mapping = inode->i_mapping;
diff --git a/fs/hfs/hfs_fs.h b/fs/hfs/hfs_fs.h
index 325214573d91..fdfa5d303d5e 100644
--- a/fs/hfs/hfs_fs.h
+++ b/fs/hfs/hfs_fs.h
@@ -143,7 +143,6 @@ struct hfs_sb_info {
 #define HFS_FLG_BITMAP_DIRTY	0
 #define HFS_FLG_MDB_DIRTY	1
 #define HFS_FLG_ALT_MDB_DIRTY	2
-#define HFS_FLG_EMERGENCY_RO	3	/* read-only after an MDB write error */
 
 /* bitmap.c */
 extern u32 hfs_vbm_search_free(struct super_block *sb, u32 goal, u32 *num_bits);
@@ -294,16 +293,6 @@ static inline const char *hfs_mdb_name(struct super_block *sb)
 	return sb->s_id;
 }
 
-/*
- * Writing back the MDB failed and the filesystem stopped all modifications
- * until unmount. SB_RDONLY isn't used for that because it must not change
- * without s_umount.
- */
-static inline bool hfs_emergency_ro(struct super_block *sb)
-{
-	return test_bit(HFS_FLG_EMERGENCY_RO, &HFS_SB(sb)->flags);
-}
-
 static inline void hfs_bitmap_dirty(struct super_block *sb)
 {
 	set_bit(HFS_FLG_BITMAP_DIRTY, &HFS_SB(sb)->flags);
diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
index 6ea3b8ffb284..71f7ddf60fb2 100644
--- a/fs/hfs/inode.c
+++ b/fs/hfs/inode.c
@@ -54,7 +54,7 @@ int hfs_write_begin(const struct kiocb *iocb, struct address_space *mapping,
 	loff_t total_capacity;
 	int ret;
 
-	if (unlikely(hfs_emergency_ro(inode->i_sb)))
+	if (unlikely(sb_emergency_ro(inode->i_sb)))
 		return -EROFS;
 
 	total_capacity = (loff_t)sbi->fs_ablocks * sbi->alloc_blksz;
@@ -143,7 +143,7 @@ static ssize_t hfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 	ssize_t ret;
 
 	if (iov_iter_rw(iter) == WRITE &&
-	    unlikely(hfs_emergency_ro(inode->i_sb)))
+	    unlikely(sb_emergency_ro(inode->i_sb)))
 		return -EROFS;
 
 	ret = blockdev_direct_IO(iocb, inode, iter, hfs_get_block);
@@ -479,11 +479,8 @@ int hfs_write_inode(struct inode *inode, struct writeback_control *wbc)
 	int res;
 
 	hfs_dbg("ino %llu\n", inode->i_ino);
-	if (unlikely(hfs_emergency_ro(inode->i_sb))) {
-		/*
-		 * Writeback still writes the b-tree nodes. Keep the headers in
-		 * sync with them so the trees on disk stay intact.
-		 */
+	if (unlikely(sb_emergency_ro(inode->i_sb))) {
+		/* Keep the headers in sync with the nodes writeback still writes. */
 		if (inode->i_ino == HFS_EXT_CNID)
 			hfs_btree_write(HFS_SB(inode->i_sb)->ext_tree);
 		else if (inode->i_ino == HFS_CAT_CNID)
@@ -640,8 +637,6 @@ void hfs_evict_inode(struct inode *inode)
 
 static int hfs_file_open(struct inode *inode, struct file *file)
 {
-	if ((file->f_mode & FMODE_WRITE) && hfs_emergency_ro(inode->i_sb))
-		return -EROFS;
 	if (HFS_IS_RSRC(inode))
 		inode = HFS_I(inode)->rsrc_inode;
 	atomic_inc(&HFS_I(inode)->opencnt);
@@ -673,9 +668,6 @@ int hfs_inode_setattr(const struct mnt_idmap *idmap, struct dentry *dentry,
 	struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
 	int error;
 
-	if (unlikely(hfs_emergency_ro(inode->i_sb)))
-		return -EROFS;
-
 	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		return error;
@@ -727,10 +719,6 @@ static int hfs_file_fsync(struct file *filp, loff_t start, loff_t end,
 	struct super_block * sb;
 	int ret, err;
 
-	/* Inodes aren't written back after an error. */
-	if (unlikely(hfs_emergency_ro(inode->i_sb)))
-		return -EROFS;
-
 	ret = file_write_and_wait_range(filp, start, end);
 	if (ret)
 		return ret;
diff --git a/fs/hfs/mdb.c b/fs/hfs/mdb.c
index 1a56cf5ea56e..b821b06121ad 100644
--- a/fs/hfs/mdb.c
+++ b/fs/hfs/mdb.c
@@ -338,7 +338,7 @@ int hfs_mdb_commit(struct super_block *sb)
 	struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
 	int ret = 0;
 
-	if (sb_rdonly(sb) || hfs_emergency_ro(sb))
+	if (sb_rdonly(sb) || sb_emergency_ro(sb))
 		return 0;
 
 	/*
@@ -347,7 +347,7 @@ int hfs_mdb_commit(struct super_block *sb)
 	 */
 	if (!buffer_uptodate(HFS_SB(sb)->mdb_bh)) {
 		pr_err("primary MDB is corrupt, mounting read-only\n");
-		set_bit(HFS_FLG_EMERGENCY_RO, &HFS_SB(sb)->flags);
+		sb_set_emergency_ro(sb);
 		return -EIO;
 	}
 
@@ -381,7 +381,7 @@ int hfs_mdb_commit(struct super_block *sb)
 	    HFS_SB(sb)->alt_mdb) {
 		if (!buffer_uptodate(HFS_SB(sb)->alt_mdb_bh)) {
 			pr_err("alternate MDB is corrupt, mounting read-only\n");
-			set_bit(HFS_FLG_EMERGENCY_RO, &HFS_SB(sb)->flags);
+			sb_set_emergency_ro(sb);
 			ret = -EIO;
 			goto out;
 		}
@@ -432,7 +432,7 @@ int hfs_mdb_commit(struct super_block *sb)
 void hfs_mdb_close(struct super_block *sb)
 {
 	/* update volume attributes */
-	if (sb_rdonly(sb) || hfs_emergency_ro(sb))
+	if (sb_rdonly(sb) || sb_emergency_ro(sb))
 		return;
 
 	if (!buffer_uptodate(HFS_SB(sb)->mdb_bh))
diff --git a/fs/hfs/super.c b/fs/hfs/super.c
index bcc19c3a4f6b..c815d22ab900 100644
--- a/fs/hfs/super.c
+++ b/fs/hfs/super.c
@@ -82,7 +82,7 @@ void hfs_mark_mdb_dirty(struct super_block *sb)
 	struct hfs_sb_info *sbi = HFS_SB(sb);
 	unsigned long delay;
 
-	if (sb_rdonly(sb) || hfs_emergency_ro(sb))
+	if (sb_rdonly(sb) || sb_emergency_ro(sb))
 		return;
 
 	spin_lock(&sbi->work_lock);
@@ -131,9 +131,6 @@ static int hfs_reconfigure(struct fs_context *fc)
 		return 0;
 
 	if (!(fc->sb_flags & SB_RDONLY)) {
-		/* After an MDB write error it stays read-only until unmount. */
-		if (hfs_emergency_ro(sb))
-			return -EROFS;
 		if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
 			pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.  leaving read-only.\n");
 			sb->s_flags |= SB_RDONLY;

-- 
2.53.0