/* * 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/spinlock.h> #include <linux/string.h> #include <linux/slab.h> #include <linux/uaccess.h> #include <linux/coda.h> #include <linux/coda_psdev.h> #include "coda_linux.h" #include "coda_int.h" static ssize_t coda_file_read_iter(struct kiocb *iocb, struct iov_iter *to) { struct file *coda_file = iocb->ki_filp; struct coda_file_info *cfi = CODA_FTOC(coda_file); BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); return vfs_iter_read(cfi->cfi_container, to, &iocb->ki_pos); } 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_iter(struct kiocb *iocb, struct iov_iter *to) { struct file *coda_file = iocb->ki_filp; struct inode *coda_inode = file_inode(coda_file); struct coda_file_info *cfi = CODA_FTOC(coda_file); struct file *host_file; ssize_t ret; BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); host_file = cfi->cfi_container; file_start_write(host_file); inode_lock(coda_inode); ret = vfs_iter_write(cfi->cfi_container, to, &iocb->ki_pos); coda_inode->i_size = file_inode(host_file)->i_size; coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9; coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC; inode_unlock(coda_inode); file_end_write(host_file); 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->mmap) return -ENODEV; coda_inode = file_inode(coda_file); host_inode = file_inode(host_file); cii = ITOC(coda_inode); spin_lock(&cii->c_lock); 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) { spin_unlock(&cii->c_lock); return -EBUSY; } /* keep track of how often the coda_inode/host_file has been mmapped */ cii->c_mapcount++; cfi->cfi_mapcount++; spin_unlock(&cii->c_lock); 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; error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags, &host_file); if (!host_file) error = -EIO; if (error) { kfree(cfi); 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; 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; 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 = file_inode(cfi->cfi_container); cii = ITOC(coda_inode); /* did we mmap this file? */ spin_lock(&cii->c_lock); 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; } spin_unlock(&cii->c_lock); fput(cfi->cfi_container); kfree(coda_file->private_data); coda_file->private_data = NULL; /* 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, loff_t start, loff_t end, int datasync) { struct file *host_file; struct inode *coda_inode = file_inode(coda_file); struct coda_file_info *cfi; int err; if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) || S_ISLNK(coda_inode->i_mode))) return -EINVAL; err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end); if (err) return err; inode_lock(coda_inode); cfi = CODA_FTOC(coda_file); BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); host_file = cfi->cfi_container; err = vfs_fsync(host_file, datasync); if (!err && !datasync) err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode)); inode_unlock(coda_inode); return err; } const struct file_operations coda_file_operations = { .llseek = generic_file_llseek, .read_iter = coda_file_read_iter, .write_iter = coda_file_write_iter, .mmap = coda_file_mmap, .open = coda_open, .release = coda_release, .fsync = coda_fsync, .splice_read = coda_file_splice_read, };