/* * linux/fs/9p/vfs_file.c * * This file contians vfs file ops for 9P2000. * * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 * as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to: * Free Software Foundation * 51 Franklin Street, Fifth Floor * Boston, MA 02111-1301 USA * */ #include <linux/module.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/sched.h> #include <linux/file.h> #include <linux/stat.h> #include <linux/string.h> #include <linux/inet.h> #include <linux/list.h> #include <asm/uaccess.h> #include <linux/idr.h> #include <net/9p/9p.h> #include <net/9p/client.h> #include "v9fs.h" #include "v9fs_vfs.h" #include "fid.h" static const struct file_operations v9fs_cached_file_operations; /** * v9fs_file_open - open a file (or directory) * @inode: inode to be opened * @file: file being opened * */ int v9fs_file_open(struct inode *inode, struct file *file) { int err; struct v9fs_session_info *v9ses; struct p9_fid *fid; int omode; P9_DPRINTK(P9_DEBUG_VFS, "inode: %p file: %p \n", inode, file); v9ses = v9fs_inode2v9ses(inode); omode = v9fs_uflags2omode(file->f_flags, v9fs_extended(v9ses)); fid = file->private_data; if (!fid) { fid = v9fs_fid_clone(file->f_path.dentry); if (IS_ERR(fid)) return PTR_ERR(fid); err = p9_client_open(fid, omode); if (err < 0) { p9_client_clunk(fid); return err; } if (omode & P9_OTRUNC) { inode->i_size = 0; inode->i_blocks = 0; } if ((file->f_flags & O_APPEND) && (!v9fs_extended(v9ses))) generic_file_llseek(file, 0, SEEK_END); } file->private_data = fid; if ((fid->qid.version) && (v9ses->cache)) { P9_DPRINTK(P9_DEBUG_VFS, "cached"); /* enable cached file options */ if(file->f_op == &v9fs_file_operations) file->f_op = &v9fs_cached_file_operations; } return 0; } /** * v9fs_file_lock - lock a file (or directory) * @filp: file to be locked * @cmd: lock command * @fl: file lock structure * * Bugs: this looks like a local only lock, we should extend into 9P * by using open exclusive */ static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl) { int res = 0; struct inode *inode = filp->f_path.dentry->d_inode; P9_DPRINTK(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl); /* No mandatory locks */ if (__mandatory_lock(inode)) return -ENOLCK; if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) { filemap_write_and_wait(inode->i_mapping); invalidate_mapping_pages(&inode->i_data, 0, -1); } return res; } /** * v9fs_file_readn - read from a file * @filp: file pointer to read * @data: data buffer to read data into * @udata: user data buffer to read data into * @count: size of buffer * @offset: offset at which to read data * */ ssize_t v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count, u64 offset) { int n, total; struct p9_fid *fid = filp->private_data; P9_DPRINTK(P9_DEBUG_VFS, "fid %d offset %llu count %d\n", fid->fid, (long long unsigned) offset, count); n = 0; total = 0; do { n = p9_client_read(fid, data, udata, offset, count); if (n <= 0) break; if (data) data += n; if (udata) udata += n; offset += n; count -= n; total += n; } while (count > 0 && n == (fid->clnt->msize - P9_IOHDRSZ)); if (n < 0) total = n; return total; } /** * v9fs_file_read - read from a file * @filp: file pointer to read * @udata: user data buffer to read data into * @count: size of buffer * @offset: offset at which to read data * */ static ssize_t v9fs_file_read(struct file *filp, char __user *udata, size_t count, loff_t * offset) { int ret; struct p9_fid *fid; P9_DPRINTK(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset); fid = filp->private_data; if (count > (fid->clnt->msize - P9_IOHDRSZ)) ret = v9fs_file_readn(filp, NULL, udata, count, *offset); else ret = p9_client_read(fid, NULL, udata, *offset, count); if (ret > 0) *offset += ret; return ret; } /** * v9fs_file_write - write to a file * @filp: file pointer to write * @data: data buffer to write data from * @count: size of buffer * @offset: offset at which to write data * */ static ssize_t v9fs_file_write(struct file *filp, const char __user * data, size_t count, loff_t * offset) { int n, rsize, total = 0; struct p9_fid *fid; struct p9_client *clnt; struct inode *inode = filp->f_path.dentry->d_inode; int origin = *offset; P9_DPRINTK(P9_DEBUG_VFS, "data %p count %d offset %x\n", data, (int)count, (int)*offset); fid = filp->private_data; clnt = fid->clnt; rsize = fid->iounit; if (!rsize || rsize > clnt->msize-P9_IOHDRSZ) rsize = clnt->msize - P9_IOHDRSZ; do { if (count < rsize) rsize = count; n = p9_client_write(fid, NULL, data+total, *offset+total, rsize); if (n <= 0) break; count -= n; total += n; } while (count > 0); if (total > 0) { invalidate_inode_pages2_range(inode->i_mapping, origin, origin+total); *offset += total; } if (*offset > inode->i_size) { inode->i_size = *offset; inode->i_blocks = (inode->i_size + 512 - 1) >> 9; } if (n < 0) return n; return total; } static const struct file_operations v9fs_cached_file_operations = { .llseek = generic_file_llseek, .read = do_sync_read, .aio_read = generic_file_aio_read, .write = v9fs_file_write, .open = v9fs_file_open, .release = v9fs_dir_release, .lock = v9fs_file_lock, .mmap = generic_file_readonly_mmap, }; const struct file_operations v9fs_file_operations = { .llseek = generic_file_llseek, .read = v9fs_file_read, .write = v9fs_file_write, .open = v9fs_file_open, .release = v9fs_dir_release, .lock = v9fs_file_lock, .mmap = generic_file_readonly_mmap, };