From b4caecd48005fbed3949dde6c1cb233142fd69e9 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 14 Jan 2015 10:42:32 +0100 Subject: fs: introduce f_op->mmap_capabilities for nommu mmap support Since "BDI: Provide backing device capability information [try #3]" the backing_dev_info structure also provides flags for the kind of mmap operation available in a nommu environment, which is entirely unrelated to it's original purpose. Introduce a new nommu-only file operation to provide this information to the nommu mmap code instead. Splitting this from the backing_dev_info structure allows to remove lots of backing_dev_info instance that aren't otherwise needed, and entirely gets rid of the concept of providing a backing_dev_info for a character device. It also removes the need for the mtd_inodefs filesystem. Signed-off-by: Christoph Hellwig Reviewed-by: Tejun Heo Acked-by: Brian Norris Signed-off-by: Jens Axboe --- drivers/mtd/mtdchar.c | 72 +++++++-------------------------------------------- 1 file changed, 10 insertions(+), 62 deletions(-) (limited to 'drivers/mtd/mtdchar.c') diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c index 53563955931b..55fa27ecf4e1 100644 --- a/drivers/mtd/mtdchar.c +++ b/drivers/mtd/mtdchar.c @@ -49,7 +49,6 @@ static DEFINE_MUTEX(mtd_mutex); */ struct mtd_file_info { struct mtd_info *mtd; - struct inode *ino; enum mtd_file_modes mode; }; @@ -59,10 +58,6 @@ static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig) return fixed_size_llseek(file, offset, orig, mfi->mtd->size); } -static int count; -static struct vfsmount *mnt; -static struct file_system_type mtd_inodefs_type; - static int mtdchar_open(struct inode *inode, struct file *file) { int minor = iminor(inode); @@ -70,7 +65,6 @@ static int mtdchar_open(struct inode *inode, struct file *file) int ret = 0; struct mtd_info *mtd; struct mtd_file_info *mfi; - struct inode *mtd_ino; pr_debug("MTD_open\n"); @@ -78,10 +72,6 @@ static int mtdchar_open(struct inode *inode, struct file *file) if ((file->f_mode & FMODE_WRITE) && (minor & 1)) return -EACCES; - ret = simple_pin_fs(&mtd_inodefs_type, &mnt, &count); - if (ret) - return ret; - mutex_lock(&mtd_mutex); mtd = get_mtd_device(NULL, devnum); @@ -95,43 +85,26 @@ static int mtdchar_open(struct inode *inode, struct file *file) goto out1; } - mtd_ino = iget_locked(mnt->mnt_sb, devnum); - if (!mtd_ino) { - ret = -ENOMEM; - goto out1; - } - if (mtd_ino->i_state & I_NEW) { - mtd_ino->i_private = mtd; - mtd_ino->i_mode = S_IFCHR; - mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info; - unlock_new_inode(mtd_ino); - } - file->f_mapping = mtd_ino->i_mapping; - /* You can't open it RW if it's not a writeable device */ if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) { ret = -EACCES; - goto out2; + goto out1; } mfi = kzalloc(sizeof(*mfi), GFP_KERNEL); if (!mfi) { ret = -ENOMEM; - goto out2; + goto out1; } - mfi->ino = mtd_ino; mfi->mtd = mtd; file->private_data = mfi; mutex_unlock(&mtd_mutex); return 0; -out2: - iput(mtd_ino); out1: put_mtd_device(mtd); out: mutex_unlock(&mtd_mutex); - simple_release_fs(&mnt, &count); return ret; } /* mtdchar_open */ @@ -148,12 +121,9 @@ static int mtdchar_close(struct inode *inode, struct file *file) if ((file->f_mode & FMODE_WRITE)) mtd_sync(mtd); - iput(mfi->ino); - put_mtd_device(mtd); file->private_data = NULL; kfree(mfi); - simple_release_fs(&mnt, &count); return 0; } /* mtdchar_close */ @@ -1117,6 +1087,13 @@ static unsigned long mtdchar_get_unmapped_area(struct file *file, ret = mtd_get_unmapped_area(mtd, len, offset, flags); return ret == -EOPNOTSUPP ? -ENODEV : ret; } + +static unsigned mtdchar_mmap_capabilities(struct file *file) +{ + struct mtd_file_info *mfi = file->private_data; + + return mtd_mmap_capabilities(mfi->mtd); +} #endif /* @@ -1160,27 +1137,10 @@ static const struct file_operations mtd_fops = { .mmap = mtdchar_mmap, #ifndef CONFIG_MMU .get_unmapped_area = mtdchar_get_unmapped_area, + .mmap_capabilities = mtdchar_mmap_capabilities, #endif }; -static const struct super_operations mtd_ops = { - .drop_inode = generic_delete_inode, - .statfs = simple_statfs, -}; - -static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type, - int flags, const char *dev_name, void *data) -{ - return mount_pseudo(fs_type, "mtd_inode:", &mtd_ops, NULL, MTD_INODE_FS_MAGIC); -} - -static struct file_system_type mtd_inodefs_type = { - .name = "mtd_inodefs", - .mount = mtd_inodefs_mount, - .kill_sb = kill_anon_super, -}; -MODULE_ALIAS_FS("mtd_inodefs"); - int __init init_mtdchar(void) { int ret; @@ -1193,23 +1153,11 @@ int __init init_mtdchar(void) return ret; } - ret = register_filesystem(&mtd_inodefs_type); - if (ret) { - pr_err("Can't register mtd_inodefs filesystem, error %d\n", - ret); - goto err_unregister_chdev; - } - - return ret; - -err_unregister_chdev: - __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd"); return ret; } void __exit cleanup_mtdchar(void) { - unregister_filesystem(&mtd_inodefs_type); __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd"); } -- cgit v1.2.3