/* * File operations for Coda. * Original version: (C) 1996 Peter Braam * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University * * Carnegie Mellon encourages users of this code to contribute improvements * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>. */ #include <linux/types.h> #include <linux/kernel.h> #include <linux/time.h> #include <linux/file.h> #include <linux/fs.h> #include <linux/stat.h> #include <linux/cred.h> #include <linux/errno.h> #include <linux/smp_lock.h> #include <linux/string.h> #include <asm/uaccess.h> #include <linux/coda.h> #include <linux/coda_linux.h> #include <linux/coda_fs_i.h> #include <linux/coda_psdev.h> #include "coda_int.h" static ssize_t coda_file_read(struct file *coda_file, char __user *buf, size_t count, loff_t *ppos) { struct coda_file_info *cfi; struct file *host_file; cfi = CODA_FTOC(coda_file); BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); host_file = cfi->cfi_container; if (!host_file->f_op || !host_file->f_op->read) return -EINVAL; return host_file->f_op->read(host_file, buf, count, ppos); } static ssize_t coda_file_splice_read(struct file *coda_file, loff_t *ppos, struct pipe_inode_info *pipe, size_t count, unsigned int flags) { ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int); struct coda_file_info *cfi; struct file *host_file; cfi = CODA_FTOC(coda_file); BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); host_file = cfi->cfi_container; splice_read = host_file->f_op->splice_read; if (!splice_read) splice_read = default_file_splice_read; return splice_read(host_file, ppos, pipe, count, flags); } static ssize_t coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos) { struct inode *host_inode, *coda_inode = coda_file->f_path.dentry->d_inode; struct coda_file_info *cfi; struct file *host_file; ssize_t ret; cfi = CODA_FTOC(coda_file); BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); host_file = cfi->cfi_container; if (!host_file->f_op || !host_file->f_op->write) return -EINVAL; host_inode = host_file->f_path.dentry->d_inode; mutex_lock(&coda_inode->i_mutex); ret = host_file->f_op->write(host_file, buf, count, ppos); coda_inode->i_size = host_inode->i_size; coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9; coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC; mutex_unlock(&coda_inode->i_mutex); return ret; } static int coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma) { struct coda_file_info *cfi; struct coda_inode_info *cii; struct file *host_file; struct inode *coda_inode, *host_inode; cfi = CODA_FTOC(coda_file); BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); host_file = cfi->cfi_container; if (!host_file->f_op || !host_file->f_op->mmap) return -ENODEV; coda_inode = coda_file->f_path.dentry->d_inode; host_inode = host_file->f_path.dentry->d_inode; coda_file->f_mapping = host_file->f_mapping; if (coda_inode->i_mapping == &coda_inode->i_data) coda_inode->i_mapping = host_inode->i_mapping; /* only allow additional mmaps as long as userspace isn't changing * the container file on us! */ else if (coda_inode->i_mapping != host_inode->i_mapping) return -EBUSY; /* keep track of how often the coda_inode/host_file has been mmapped */ cii = ITOC(coda_inode); cii->c_mapcount++; cfi->cfi_mapcount++; return host_file->f_op->mmap(host_file, vma); } int coda_open(struct inode *coda_inode, struct file *coda_file) { struct file *host_file = NULL; int error; unsigned short flags = coda_file->f_flags & (~O_EXCL); unsigned short coda_flags = coda_flags_to_cflags(flags); struct coda_file_info *cfi; cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL); if (!cfi) return -ENOMEM; lock_kernel(); error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags, &host_file); if (!host_file) error = -EIO; if (error) { kfree(cfi); unlock_kernel(); return error; } host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC); cfi->cfi_magic = CODA_MAGIC; cfi->cfi_mapcount = 0; cfi->cfi_container = host_file; BUG_ON(coda_file->private_data != NULL); coda_file->private_data = cfi; unlock_kernel(); return 0; } int coda_release(struct inode *coda_inode, struct file *coda_file) { unsigned short flags = (coda_file->f_flags) & (~O_EXCL); unsigned short coda_flags = coda_flags_to_cflags(flags); struct coda_file_info *cfi; struct coda_inode_info *cii; struct inode *host_inode; int err = 0; lock_kernel(); cfi = CODA_FTOC(coda_file); BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags, coda_file->f_cred->fsuid); host_inode = cfi->cfi_container->f_path.dentry->d_inode; cii = ITOC(coda_inode); /* did we mmap this file? */ if (coda_inode->i_mapping == &host_inode->i_data) { cii->c_mapcount -= cfi->cfi_mapcount; if (!cii->c_mapcount) coda_inode->i_mapping = &coda_inode->i_data; } fput(cfi->cfi_container); kfree(coda_file->private_data); coda_file->private_data = NULL; unlock_kernel(); /* VFS fput ignores the return value from file_operations->release, so * there is no use returning an error here */ return 0; } int coda_fsync(struct file *coda_file, struct dentry *coda_dentry, int datasync) { struct file *host_file; struct inode *coda_inode = coda_dentry->d_inode; struct coda_file_info *cfi; int err = 0; if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) || S_ISLNK(coda_inode->i_mode))) return -EINVAL; cfi = CODA_FTOC(coda_file); BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); host_file = cfi->cfi_container; err = vfs_fsync(host_file, host_file->f_path.dentry, datasync); if ( !err && !datasync ) { lock_kernel(); err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode)); unlock_kernel(); } return err; } const struct file_operations coda_file_operations = { .llseek = generic_file_llseek, .read = coda_file_read, .write = coda_file_write, .mmap = coda_file_mmap, .open = coda_open, .release = coda_release, .fsync = coda_fsync, .splice_read = coda_file_splice_read, };