1 /* 2 * linux/fs/9p/vfs_file.c 3 * 4 * This file contians vfs file ops for 9P2000. 5 * 6 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> 7 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 11 * as published by the Free Software Foundation. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to: 20 * Free Software Foundation 21 * 51 Franklin Street, Fifth Floor 22 * Boston, MA 02111-1301 USA 23 * 24 */ 25 26 #include <linux/module.h> 27 #include <linux/errno.h> 28 #include <linux/fs.h> 29 #include <linux/sched.h> 30 #include <linux/file.h> 31 #include <linux/stat.h> 32 #include <linux/string.h> 33 #include <linux/inet.h> 34 #include <linux/list.h> 35 #include <asm/uaccess.h> 36 #include <linux/idr.h> 37 #include <net/9p/9p.h> 38 #include <net/9p/client.h> 39 40 #include "v9fs.h" 41 #include "v9fs_vfs.h" 42 #include "fid.h" 43 44 static const struct file_operations v9fs_cached_file_operations; 45 46 /** 47 * v9fs_file_open - open a file (or directory) 48 * @inode: inode to be opened 49 * @file: file being opened 50 * 51 */ 52 53 int v9fs_file_open(struct inode *inode, struct file *file) 54 { 55 int err; 56 struct v9fs_session_info *v9ses; 57 struct p9_fid *fid; 58 int omode; 59 60 P9_DPRINTK(P9_DEBUG_VFS, "inode: %p file: %p \n", inode, file); 61 v9ses = v9fs_inode2v9ses(inode); 62 omode = v9fs_uflags2omode(file->f_flags); 63 fid = file->private_data; 64 if (!fid) { 65 fid = v9fs_fid_clone(file->f_path.dentry); 66 if (IS_ERR(fid)) 67 return PTR_ERR(fid); 68 69 err = p9_client_open(fid, omode); 70 if (err < 0) { 71 p9_client_clunk(fid); 72 return err; 73 } 74 if (omode & P9_OTRUNC) { 75 inode->i_size = 0; 76 inode->i_blocks = 0; 77 } 78 } 79 80 file->private_data = fid; 81 if ((fid->qid.version) && (v9ses->cache)) { 82 P9_DPRINTK(P9_DEBUG_VFS, "cached"); 83 /* enable cached file options */ 84 if(file->f_op == &v9fs_file_operations) 85 file->f_op = &v9fs_cached_file_operations; 86 } 87 88 return 0; 89 } 90 91 /** 92 * v9fs_file_lock - lock a file (or directory) 93 * @inode: inode to be opened 94 * @file: file being opened 95 * 96 * XXX - this looks like a local only lock, we should extend into 9P 97 * by using open exclusive 98 */ 99 100 static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl) 101 { 102 int res = 0; 103 struct inode *inode = filp->f_path.dentry->d_inode; 104 105 P9_DPRINTK(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl); 106 107 /* No mandatory locks */ 108 if (__mandatory_lock(inode)) 109 return -ENOLCK; 110 111 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) { 112 filemap_write_and_wait(inode->i_mapping); 113 invalidate_mapping_pages(&inode->i_data, 0, -1); 114 } 115 116 return res; 117 } 118 119 /** 120 * v9fs_file_read - read from a file 121 * @filep: file pointer to read 122 * @data: data buffer to read data into 123 * @count: size of buffer 124 * @offset: offset at which to read data 125 * 126 */ 127 static ssize_t 128 v9fs_file_read(struct file *filp, char __user * data, size_t count, 129 loff_t * offset) 130 { 131 int ret; 132 struct p9_fid *fid; 133 134 P9_DPRINTK(P9_DEBUG_VFS, "\n"); 135 fid = filp->private_data; 136 ret = p9_client_uread(fid, data, *offset, count); 137 if (ret > 0) 138 *offset += ret; 139 140 return ret; 141 } 142 143 /** 144 * v9fs_file_write - write to a file 145 * @filep: file pointer to write 146 * @data: data buffer to write data from 147 * @count: size of buffer 148 * @offset: offset at which to write data 149 * 150 */ 151 152 static ssize_t 153 v9fs_file_write(struct file *filp, const char __user * data, 154 size_t count, loff_t * offset) 155 { 156 int ret; 157 struct p9_fid *fid; 158 struct inode *inode = filp->f_path.dentry->d_inode; 159 160 P9_DPRINTK(P9_DEBUG_VFS, "data %p count %d offset %x\n", data, 161 (int)count, (int)*offset); 162 163 fid = filp->private_data; 164 ret = p9_client_uwrite(fid, data, *offset, count); 165 if (ret > 0) { 166 invalidate_inode_pages2_range(inode->i_mapping, *offset, 167 *offset+ret); 168 *offset += ret; 169 } 170 171 if (*offset > inode->i_size) { 172 inode->i_size = *offset; 173 inode->i_blocks = (inode->i_size + 512 - 1) >> 9; 174 } 175 176 return ret; 177 } 178 179 static const struct file_operations v9fs_cached_file_operations = { 180 .llseek = generic_file_llseek, 181 .read = do_sync_read, 182 .aio_read = generic_file_aio_read, 183 .write = v9fs_file_write, 184 .open = v9fs_file_open, 185 .release = v9fs_dir_release, 186 .lock = v9fs_file_lock, 187 .mmap = generic_file_readonly_mmap, 188 }; 189 190 const struct file_operations v9fs_file_operations = { 191 .llseek = generic_file_llseek, 192 .read = v9fs_file_read, 193 .write = v9fs_file_write, 194 .open = v9fs_file_open, 195 .release = v9fs_dir_release, 196 .lock = v9fs_file_lock, 197 .mmap = generic_file_readonly_mmap, 198 }; 199