HPFS: Introduce a global mutex and lock it on every callback from VFS. (7dd29d8d) · Commits · 戴 / test

fs/hpfs/buffer.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -32,6 +32,8 @@ void hpfs_map_sector(struct super_block s, unsigned secno, struct buffer_head
		{
		struct buffer_head *bh;

		hpfs_lock_assert(s);

		cond_resched();

		*bhp = bh = sb_bread(s, secno);
		@@ -50,6 +52,8 @@ void hpfs_get_sector(struct super_block s, unsigned secno, struct buffer_head
		struct buffer_head *bh;
		/return hpfs_map_sector(s, secno, bhp, 0);/

		hpfs_lock_assert(s);

		cond_resched();

		if ((*bhp = bh = sb_getblk(s, secno)) != NULL) {
		@@ -70,6 +74,8 @@ void hpfs_map_4sectors(struct super_block s, unsigned secno, struct quad_buffe
		struct buffer_head *bh;
		char *data;

		hpfs_lock_assert(s);

		cond_resched();

		if (secno & 3) {
		@@ -125,6 +131,8 @@ void hpfs_get_4sectors(struct super_block s, unsigned secno,
		{
		cond_resched();

		hpfs_lock_assert(s);

		if (secno & 3) {
		printk("HPFS: hpfs_get_4sectors: unaligned read\n");
		return NULL;

fs/hpfs/file.c

+19 −8

Original line number	Diff line number	Diff line
		@@ -48,38 +48,46 @@ static secno hpfs_bmap(struct inode *inode, unsigned file_secno)
		static void hpfs_truncate(struct inode *i)
		{
		if (IS_IMMUTABLE(i)) return /-EPERM/;
		hpfs_lock(i->i_sb);
		hpfs_lock_assert(i->i_sb);

		hpfs_i(i)->i_n_secs = 0;
		i->i_blocks = 1 + ((i->i_size + 511) >> 9);
		hpfs_i(i)->mmu_private = i->i_size;
		hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
		hpfs_write_inode(i);
		hpfs_i(i)->i_n_secs = 0;
		hpfs_unlock(i->i_sb);
		}

		static int hpfs_get_block(struct inode inode, sector_t iblock, struct buffer_head bh_result, int create)
		{
		int r;
		secno s;
		hpfs_lock(inode->i_sb);
		s = hpfs_bmap(inode, iblock);
		if (s) {
		map_bh(bh_result, inode->i_sb, s);
		return 0;
		goto ret_0;
		}
		if (!create) return 0;
		if (!create) goto ret_0;
		if (iblock<<9 != hpfs_i(inode)->mmu_private) {
		BUG();
		return -EIO;
		r = -EIO;
		goto ret_r;
		}
		if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) {
		hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1);
		return -ENOSPC;
		r = -ENOSPC;
		goto ret_r;
		}
		inode->i_blocks++;
		hpfs_i(inode)->mmu_private += 512;
		set_buffer_new(bh_result);
		map_bh(bh_result, inode->i_sb, s);
		return 0;
		ret_0:
		r = 0;
		ret_r:
		hpfs_unlock(inode->i_sb);
		return r;
		}

		static int hpfs_writepage(struct page page, struct writeback_control wbc)
		@@ -130,8 +138,11 @@ static ssize_t hpfs_file_write(struct file file, const char __user buf,
		ssize_t retval;

		retval = do_sync_write(file, buf, count, ppos);
		if (retval > 0)
		if (retval > 0) {
		hpfs_lock(file->f_path.dentry->d_sb);
		hpfs_i(file->f_path.dentry->d_inode)->i_dirty = 1;
		hpfs_unlock(file->f_path.dentry->d_sb);
		}
		return retval;
		}

fs/hpfs/hpfs_fn.h

+15 −9

Original line number	Diff line number	Diff line
		@@ -63,6 +63,7 @@ struct hpfs_inode_info {
		};

		struct hpfs_sb_info {
		struct mutex hpfs_mutex; /* global hpfs lock */
		ino_t sb_root; /* inode number of root dir */
		unsigned sb_fs_size; /* file system size, sectors */
		unsigned sb_bitmaps; /* sector number of bitmap list */
		@@ -346,21 +347,26 @@ static inline time32_t gmt_to_local(struct super_block *s, time_t t)
		/*
		* Locking:
		*
		* hpfs_lock() is a leftover from the big kernel lock.
		* Right now, these functions are empty and only left
		* for documentation purposes. The file system no longer
		* works on SMP systems, so the lock is not needed
		* any more.
		* hpfs_lock() locks the whole filesystem. It must be taken
		* on any method called by the VFS.
		*
		* If someone is interested in making it work again, this
		* would be the place to start by adding a per-superblock
		* mutex and fixing all the bugs and performance issues
		* caused by that.
		* We don't do any per-file locking anymore, it is hard to
		* review and HPFS is not performance-sensitive anyway.
		*/
		static inline void hpfs_lock(struct super_block *s)
		{
		struct hpfs_sb_info *sbi = hpfs_sb(s);
		mutex_lock(&sbi->hpfs_mutex);
		}

		static inline void hpfs_unlock(struct super_block *s)
		{
		struct hpfs_sb_info *sbi = hpfs_sb(s);
		mutex_unlock(&sbi->hpfs_mutex);
		}

		static inline void hpfs_lock_assert(struct super_block *s)
		{
		struct hpfs_sb_info *sbi = hpfs_sb(s);
		WARN_ON(!mutex_is_locked(&sbi->hpfs_mutex));
		}

fs/hpfs/super.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -102,9 +102,12 @@ static void hpfs_put_super(struct super_block *s)
		{
		struct hpfs_sb_info *sbi = hpfs_sb(s);

		hpfs_lock(s);
		unmark_dirty(s);
		hpfs_unlock(s);

		kfree(sbi->sb_cp_table);
		kfree(sbi->sb_bmp_dir);
		unmark_dirty(s);
		s->s_fs_info = NULL;
		kfree(sbi);
		}
		@@ -490,6 +493,9 @@ static int hpfs_fill_super(struct super_block s, void options, int silent)
		sbi->sb_bmp_dir = NULL;
		sbi->sb_cp_table = NULL;

		mutex_init(&sbi->hpfs_mutex);
		hpfs_lock(s);

		mutex_init(&sbi->hpfs_creation_de);

		uid = current_uid();
		@@ -669,6 +675,7 @@ static int hpfs_fill_super(struct super_block s, void options, int silent)
		root->i_blocks = 5;
		hpfs_brelse4(&qbh);
		}
		hpfs_unlock(s);
		return 0;

		bail4: brelse(bh2);
		@@ -676,6 +683,7 @@ bail3: brelse(bh1);
		bail2: brelse(bh0);
		bail1:
		bail0:
		hpfs_unlock(s);
		kfree(sbi->sb_bmp_dir);
		kfree(sbi->sb_cp_table);
		s->s_fs_info = NULL;

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