diff options
Diffstat (limited to 'drivers/gator/gator_fs.c')
-rw-r--r-- | drivers/gator/gator_fs.c | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/drivers/gator/gator_fs.c b/drivers/gator/gator_fs.c new file mode 100644 index 00000000000..39adfbecd06 --- /dev/null +++ b/drivers/gator/gator_fs.c @@ -0,0 +1,292 @@ +/** + * @file gatorfs.c + * + * @remark Copyright 2002 OProfile authors + * @remark Read the file COPYING + * + * @author John Levon + * + * A simple filesystem for configuration and + * access of oprofile. + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/pagemap.h> +#include <asm/uaccess.h> + +#define gatorfs_MAGIC 0x24051020 +#define TMPBUFSIZE 50 +DEFINE_SPINLOCK(gatorfs_lock); + +static struct inode *gatorfs_get_inode(struct super_block *sb, int mode) +{ + struct inode *inode = new_inode(sb); + + if (inode) { +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 37) + inode->i_ino = get_next_ino(); +#endif + inode->i_mode = mode; + inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; + } + return inode; +} + +static const struct super_operations s_ops = { + .statfs = simple_statfs, + .drop_inode = generic_delete_inode, +}; + +ssize_t gatorfs_str_to_user(char const *str, char __user *buf, size_t count, loff_t *offset) +{ + return simple_read_from_buffer(buf, count, offset, str, strlen(str)); +} + +ssize_t gatorfs_ulong_to_user(unsigned long val, char __user *buf, size_t count, loff_t *offset) +{ + char tmpbuf[TMPBUFSIZE]; + size_t maxlen = snprintf(tmpbuf, TMPBUFSIZE, "%lu\n", val); + if (maxlen > TMPBUFSIZE) + maxlen = TMPBUFSIZE; + return simple_read_from_buffer(buf, count, offset, tmpbuf, maxlen); +} + +int gatorfs_ulong_from_user(unsigned long *val, char const __user *buf, size_t count) +{ + char tmpbuf[TMPBUFSIZE]; + unsigned long flags; + + if (!count) + return 0; + + if (count > TMPBUFSIZE - 1) + return -EINVAL; + + memset(tmpbuf, 0x0, TMPBUFSIZE); + + if (copy_from_user(tmpbuf, buf, count)) + return -EFAULT; + + spin_lock_irqsave(&gatorfs_lock, flags); + *val = simple_strtoul(tmpbuf, NULL, 0); + spin_unlock_irqrestore(&gatorfs_lock, flags); + return 0; +} + +static ssize_t ulong_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset) +{ + unsigned long *val = file->private_data; + return gatorfs_ulong_to_user(*val, buf, count, offset); +} + +static ssize_t ulong_write_file(struct file *file, char const __user *buf, size_t count, loff_t *offset) +{ + unsigned long *value = file->private_data; + int retval; + + if (*offset) + return -EINVAL; + + retval = gatorfs_ulong_from_user(value, buf, count); + + if (retval) + return retval; + return count; +} + +static int default_open(struct inode *inode, struct file *filp) +{ + if (inode->i_private) + filp->private_data = inode->i_private; + return 0; +} + +static const struct file_operations ulong_fops = { + .read = ulong_read_file, + .write = ulong_write_file, + .open = default_open, +}; + +static const struct file_operations ulong_ro_fops = { + .read = ulong_read_file, + .open = default_open, +}; + +static struct dentry *__gatorfs_create_file(struct super_block *sb, + struct dentry *root, char const *name, const struct file_operations *fops, + int perm) +{ + struct dentry *dentry; + struct inode *inode; + + dentry = d_alloc_name(root, name); + if (!dentry) + return NULL; + inode = gatorfs_get_inode(sb, S_IFREG | perm); + if (!inode) { + dput(dentry); + return NULL; + } + inode->i_fop = fops; + d_add(dentry, inode); + return dentry; +} + +int gatorfs_create_ulong(struct super_block *sb, struct dentry *root, + char const *name, unsigned long *val) +{ + struct dentry *d = __gatorfs_create_file(sb, root, name, + &ulong_fops, 0644); + if (!d) + return -EFAULT; + + d->d_inode->i_private = val; + return 0; +} + +int gatorfs_create_ro_ulong(struct super_block *sb, struct dentry *root, + char const *name, unsigned long *val) +{ + struct dentry *d = __gatorfs_create_file(sb, root, name, + &ulong_ro_fops, 0444); + if (!d) + return -EFAULT; + + d->d_inode->i_private = val; + return 0; +} + +static ssize_t atomic_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset) +{ + atomic_t *val = file->private_data; + return gatorfs_ulong_to_user(atomic_read(val), buf, count, offset); +} + +static const struct file_operations atomic_ro_fops = { + .read = atomic_read_file, + .open = default_open, +}; + +int gatorfs_create_ro_atomic(struct super_block *sb, struct dentry *root, + char const *name, atomic_t *val) +{ + struct dentry *d = __gatorfs_create_file(sb, root, name, + &atomic_ro_fops, 0444); + if (!d) + return -EFAULT; + + d->d_inode->i_private = val; + return 0; +} + +int gatorfs_create_file(struct super_block *sb, struct dentry *root, + char const *name, const struct file_operations *fops) +{ + if (!__gatorfs_create_file(sb, root, name, fops, 0644)) + return -EFAULT; + return 0; +} + +int gatorfs_create_file_perm(struct super_block *sb, struct dentry *root, + char const *name, const struct file_operations *fops, int perm) +{ + if (!__gatorfs_create_file(sb, root, name, fops, perm)) + return -EFAULT; + return 0; +} + +struct dentry *gatorfs_mkdir(struct super_block *sb, + struct dentry *root, char const *name) +{ + struct dentry *dentry; + struct inode *inode; + + dentry = d_alloc_name(root, name); + if (!dentry) + return NULL; + inode = gatorfs_get_inode(sb, S_IFDIR | 0755); + if (!inode) { + dput(dentry); + return NULL; + } + inode->i_op = &simple_dir_inode_operations; + inode->i_fop = &simple_dir_operations; + d_add(dentry, inode); + return dentry; +} + +static int gatorfs_fill_super(struct super_block *sb, void *data, int silent) +{ + struct inode *root_inode; + struct dentry *root_dentry; + + sb->s_blocksize = PAGE_CACHE_SIZE; + sb->s_blocksize_bits = PAGE_CACHE_SHIFT; + sb->s_magic = gatorfs_MAGIC; + sb->s_op = &s_ops; + sb->s_time_gran = 1; + + root_inode = gatorfs_get_inode(sb, S_IFDIR | 0755); + if (!root_inode) + return -ENOMEM; + root_inode->i_op = &simple_dir_inode_operations; + root_inode->i_fop = &simple_dir_operations; + +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 4, 0) + root_dentry = d_alloc_root(root_inode); +#else + root_dentry = d_make_root(root_inode); +#endif + + if (!root_dentry) { +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 4, 0) + iput(root_inode); +#endif + return -ENOMEM; + } + + sb->s_root = root_dentry; + + gator_op_create_files(sb, root_dentry); + + // FIXME: verify kill_litter_super removes our dentries + return 0; +} + +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 39) +static int gatorfs_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data, struct vfsmount *mnt) +{ + return get_sb_single(fs_type, flags, data, gatorfs_fill_super, mnt); +} +#else +static struct dentry *gatorfs_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data) +{ + return mount_nodev(fs_type, flags, data, gatorfs_fill_super); +} +#endif + +static struct file_system_type gatorfs_type = { + .owner = THIS_MODULE, + .name = "gatorfs", +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 39) + .get_sb = gatorfs_get_sb, +#else + .mount = gatorfs_mount, +#endif + + .kill_sb = kill_litter_super, +}; + +int __init gatorfs_register(void) +{ + return register_filesystem(&gatorfs_type); +} + +void gatorfs_unregister(void) +{ + unregister_filesystem(&gatorfs_type); +} |