diff options
| -rw-r--r-- | drivers/mtd/mtdchar.c | 95 |
1 files changed, 87 insertions, 8 deletions
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c index c355491d132..8bb5e4a6632 100644 --- a/drivers/mtd/mtdchar.c +++ b/drivers/mtd/mtdchar.c @@ -15,12 +15,15 @@ #include <linux/smp_lock.h> #include <linux/backing-dev.h> #include <linux/compat.h> +#include <linux/mount.h> #include <linux/mtd/mtd.h> #include <linux/mtd/compatmac.h> #include <asm/uaccess.h> +#define MTD_INODE_FS_MAGIC 0x11307854 +static struct vfsmount *mtd_inode_mnt __read_mostly; /* * Data structure to hold the pointer to the mtd device as well @@ -28,6 +31,7 @@ */ struct mtd_file_info { struct mtd_info *mtd; + struct inode *ino; enum mtd_file_modes mode; }; @@ -64,6 +68,7 @@ static int mtd_open(struct inode *inode, struct file *file) int ret = 0; struct mtd_info *mtd; struct mtd_file_info *mfi; + struct inode *mtd_ino; DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n"); @@ -85,11 +90,23 @@ static int mtd_open(struct inode *inode, struct file *file) goto out; } - if (mtd->backing_dev_info) - file->f_mapping->backing_dev_info = mtd->backing_dev_info; + mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum); + if (!mtd_ino) { + put_mtd_device(mtd); + ret = -ENOMEM; + goto out; + } + 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)) { + iput(mtd_ino); put_mtd_device(mtd); ret = -EACCES; goto out; @@ -97,10 +114,12 @@ static int mtd_open(struct inode *inode, struct file *file) mfi = kzalloc(sizeof(*mfi), GFP_KERNEL); if (!mfi) { + iput(mtd_ino); put_mtd_device(mtd); ret = -ENOMEM; goto out; } + mfi->ino = mtd_ino; mfi->mtd = mtd; file->private_data = mfi; @@ -122,6 +141,8 @@ static int mtd_close(struct inode *inode, struct file *file) if ((file->f_mode & FMODE_WRITE) && mtd->sync) mtd->sync(mtd); + iput(mfi->ino); + put_mtd_device(mtd); file->private_data = NULL; kfree(mfi); @@ -951,22 +972,80 @@ static const struct file_operations mtd_fops = { #endif }; +static int mtd_inodefs_get_sb(struct file_system_type *fs_type, int flags, + const char *dev_name, void *data, + struct vfsmount *mnt) +{ + return get_sb_pseudo(fs_type, "mtd_inode:", NULL, MTD_INODE_FS_MAGIC, + mnt); +} + +static struct file_system_type mtd_inodefs_type = { + .name = "mtd_inodefs", + .get_sb = mtd_inodefs_get_sb, + .kill_sb = kill_anon_super, +}; + +static void mtdchar_notify_add(struct mtd_info *mtd) +{ +} + +static void mtdchar_notify_remove(struct mtd_info *mtd) +{ + struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index); + + if (mtd_ino) { + /* Destroy the inode if it exists */ + mtd_ino->i_nlink = 0; + iput(mtd_ino); + } +} + +static struct mtd_notifier mtdchar_notifier = { + .add = mtdchar_notify_add, + .remove = mtdchar_notify_remove, +}; + static int __init init_mtdchar(void) { - int status; + int ret; - status = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, + ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd", &mtd_fops); - if (status < 0) { - printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n", - MTD_CHAR_MAJOR); + if (ret < 0) { + pr_notice("Can't allocate major number %d for " + "Memory Technology Devices.\n", MTD_CHAR_MAJOR); + return ret; } - return status; + ret = register_filesystem(&mtd_inodefs_type); + if (ret) { + pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret); + goto err_unregister_chdev; + } + + mtd_inode_mnt = kern_mount(&mtd_inodefs_type); + if (IS_ERR(mtd_inode_mnt)) { + ret = PTR_ERR(mtd_inode_mnt); + pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret); + goto err_unregister_filesystem; + } + register_mtd_user(&mtdchar_notifier); + + return ret; + +err_unregister_filesystem: + unregister_filesystem(&mtd_inodefs_type); +err_unregister_chdev: + __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd"); + return ret; } static void __exit cleanup_mtdchar(void) { + unregister_mtd_user(&mtdchar_notifier); + mntput(mtd_inode_mnt); + unregister_filesystem(&mtd_inodefs_type); __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd"); } |