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, v9fs_extended(v9ses)); 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 if ((file->f_flags & O_APPEND) && (!v9fs_extended(v9ses))) 79 generic_file_llseek(file, 0, SEEK_END); 80 } 81 82 file->private_data = fid; 83 if ((fid->qid.version) && (v9ses->cache)) { 84 P9_DPRINTK(P9_DEBUG_VFS, "cached"); 85 /* enable cached file options */ 86 if(file->f_op == &v9fs_file_operations) 87 file->f_op = &v9fs_cached_file_operations; 88 } 89 90 return 0; 91 } 92 93 /** 94 * v9fs_file_lock - lock a file (or directory) 95 * @filp: file to be locked 96 * @cmd: lock command 97 * @fl: file lock structure 98 * 99 * Bugs: this looks like a local only lock, we should extend into 9P 100 * by using open exclusive 101 */ 102 103 static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl) 104 { 105 int res = 0; 106 struct inode *inode = filp->f_path.dentry->d_inode; 107 108 P9_DPRINTK(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl); 109 110 /* No mandatory locks */ 111 if (__mandatory_lock(inode)) 112 return -ENOLCK; 113 114 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) { 115 filemap_write_and_wait(inode->i_mapping); 116 invalidate_mapping_pages(&inode->i_data, 0, -1); 117 } 118 119 return res; 120 } 121 122 /** 123 * v9fs_file_read - read from a file 124 * @filp: file pointer to read 125 * @data: data buffer to read data into 126 * @count: size of buffer 127 * @offset: offset at which to read data 128 * 129 */ 130 static ssize_t 131 v9fs_file_read(struct file *filp, char __user * data, size_t count, 132 loff_t * offset) 133 { 134 int ret; 135 struct p9_fid *fid; 136 137 P9_DPRINTK(P9_DEBUG_VFS, "\n"); 138 fid = filp->private_data; 139 ret = p9_client_read(fid, NULL, data, *offset, count); 140 if (ret > 0) 141 *offset += ret; 142 143 return ret; 144 } 145 146 /** 147 * v9fs_file_write - write to a file 148 * @filp: file pointer to write 149 * @data: data buffer to write data from 150 * @count: size of buffer 151 * @offset: offset at which to write data 152 * 153 */ 154 155 static ssize_t 156 v9fs_file_write(struct file *filp, const char __user * data, 157 size_t count, loff_t * offset) 158 { 159 int ret; 160 struct p9_fid *fid; 161 struct inode *inode = filp->f_path.dentry->d_inode; 162 163 P9_DPRINTK(P9_DEBUG_VFS, "data %p count %d offset %x\n", data, 164 (int)count, (int)*offset); 165 166 fid = filp->private_data; 167 ret = p9_client_write(fid, NULL, data, *offset, count); 168 if (ret > 0) { 169 invalidate_inode_pages2_range(inode->i_mapping, *offset, 170 *offset+ret); 171 *offset += ret; 172 } 173 174 if (*offset > inode->i_size) { 175 inode->i_size = *offset; 176 inode->i_blocks = (inode->i_size + 512 - 1) >> 9; 177 } 178 179 return ret; 180 } 181 182 static const struct file_operations v9fs_cached_file_operations = { 183 .llseek = generic_file_llseek, 184 .read = do_sync_read, 185 .aio_read = generic_file_aio_read, 186 .write = v9fs_file_write, 187 .open = v9fs_file_open, 188 .release = v9fs_dir_release, 189 .lock = v9fs_file_lock, 190 .mmap = generic_file_readonly_mmap, 191 }; 192 193 const struct file_operations v9fs_file_operations = { 194 .llseek = generic_file_llseek, 195 .read = v9fs_file_read, 196 .write = v9fs_file_write, 197 .open = v9fs_file_open, 198 .release = v9fs_dir_release, 199 .lock = v9fs_file_lock, 200 .mmap = generic_file_readonly_mmap, 201 }; 202