Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * File operations for Coda. |
| 3 | * Original version: (C) 1996 Peter Braam |
| 4 | * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University |
| 5 | * |
| 6 | * Carnegie Mellon encourages users of this code to contribute improvements |
| 7 | * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>. |
| 8 | */ |
| 9 | |
| 10 | #include <linux/types.h> |
| 11 | #include <linux/kernel.h> |
| 12 | #include <linux/time.h> |
| 13 | #include <linux/file.h> |
| 14 | #include <linux/fs.h> |
| 15 | #include <linux/stat.h> |
Randy Dunlap | 7596b27 | 2008-11-19 11:30:27 -0800 | [diff] [blame] | 16 | #include <linux/cred.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/errno.h> |
Yoshihisa Abe | b5ce1d8 | 2010-10-25 02:03:44 -0400 | [diff] [blame] | 18 | #include <linux/spinlock.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | #include <linux/string.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 20 | #include <linux/slab.h> |
Fabian Frederick | 834b46c | 2014-08-08 14:20:33 -0700 | [diff] [blame] | 21 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | |
| 23 | #include <linux/coda.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | #include <linux/coda_psdev.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | |
Al Viro | 31a203d | 2011-01-12 16:36:09 -0500 | [diff] [blame] | 26 | #include "coda_linux.h" |
Adrian Bunk | c98d8cf | 2006-03-24 03:15:53 -0800 | [diff] [blame] | 27 | #include "coda_int.h" |
| 28 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | static ssize_t |
Al Viro | c12c49e | 2015-04-03 10:58:11 -0400 | [diff] [blame] | 30 | coda_file_read_iter(struct kiocb *iocb, struct iov_iter *to) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | { |
Al Viro | c12c49e | 2015-04-03 10:58:11 -0400 | [diff] [blame] | 32 | struct file *coda_file = iocb->ki_filp; |
| 33 | struct coda_file_info *cfi = CODA_FTOC(coda_file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | |
Al Viro | c12c49e | 2015-04-03 10:58:11 -0400 | [diff] [blame] | 37 | return vfs_iter_read(cfi->cfi_container, to, &iocb->ki_pos); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | } |
| 39 | |
| 40 | static ssize_t |
Al Viro | c12c49e | 2015-04-03 10:58:11 -0400 | [diff] [blame] | 41 | coda_file_write_iter(struct kiocb *iocb, struct iov_iter *to) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | { |
Al Viro | c12c49e | 2015-04-03 10:58:11 -0400 | [diff] [blame] | 43 | struct file *coda_file = iocb->ki_filp; |
| 44 | struct inode *coda_inode = file_inode(coda_file); |
| 45 | struct coda_file_info *cfi = CODA_FTOC(coda_file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | struct file *host_file; |
| 47 | ssize_t ret; |
| 48 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); |
Al Viro | c12c49e | 2015-04-03 10:58:11 -0400 | [diff] [blame] | 50 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | host_file = cfi->cfi_container; |
Al Viro | 03d95eb | 2013-03-20 13:04:20 -0400 | [diff] [blame] | 52 | file_start_write(host_file); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 53 | inode_lock(coda_inode); |
Al Viro | c12c49e | 2015-04-03 10:58:11 -0400 | [diff] [blame] | 54 | ret = vfs_iter_write(cfi->cfi_container, to, &iocb->ki_pos); |
| 55 | coda_inode->i_size = file_inode(host_file)->i_size; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9; |
Deepa Dinamani | 02027d4 | 2016-09-14 07:48:05 -0700 | [diff] [blame] | 57 | coda_inode->i_mtime = coda_inode->i_ctime = current_time(coda_inode); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 58 | inode_unlock(coda_inode); |
Al Viro | 03d95eb | 2013-03-20 13:04:20 -0400 | [diff] [blame] | 59 | file_end_write(host_file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | return ret; |
| 61 | } |
| 62 | |
Jan Harkes | c93b747 | 2019-07-16 16:28:04 -0700 | [diff] [blame] | 63 | struct coda_vm_ops { |
| 64 | atomic_t refcnt; |
| 65 | struct file *coda_file; |
| 66 | const struct vm_operations_struct *host_vm_ops; |
| 67 | struct vm_operations_struct vm_ops; |
| 68 | }; |
| 69 | |
| 70 | static void |
| 71 | coda_vm_open(struct vm_area_struct *vma) |
| 72 | { |
| 73 | struct coda_vm_ops *cvm_ops = |
| 74 | container_of(vma->vm_ops, struct coda_vm_ops, vm_ops); |
| 75 | |
| 76 | atomic_inc(&cvm_ops->refcnt); |
| 77 | |
| 78 | if (cvm_ops->host_vm_ops && cvm_ops->host_vm_ops->open) |
| 79 | cvm_ops->host_vm_ops->open(vma); |
| 80 | } |
| 81 | |
| 82 | static void |
| 83 | coda_vm_close(struct vm_area_struct *vma) |
| 84 | { |
| 85 | struct coda_vm_ops *cvm_ops = |
| 86 | container_of(vma->vm_ops, struct coda_vm_ops, vm_ops); |
| 87 | |
| 88 | if (cvm_ops->host_vm_ops && cvm_ops->host_vm_ops->close) |
| 89 | cvm_ops->host_vm_ops->close(vma); |
| 90 | |
| 91 | if (atomic_dec_and_test(&cvm_ops->refcnt)) { |
| 92 | vma->vm_ops = cvm_ops->host_vm_ops; |
| 93 | fput(cvm_ops->coda_file); |
| 94 | kfree(cvm_ops); |
| 95 | } |
| 96 | } |
| 97 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | static int |
| 99 | coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma) |
| 100 | { |
| 101 | struct coda_file_info *cfi; |
| 102 | struct coda_inode_info *cii; |
| 103 | struct file *host_file; |
| 104 | struct inode *coda_inode, *host_inode; |
Jan Harkes | c93b747 | 2019-07-16 16:28:04 -0700 | [diff] [blame] | 105 | struct coda_vm_ops *cvm_ops; |
| 106 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | |
| 108 | cfi = CODA_FTOC(coda_file); |
| 109 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); |
| 110 | host_file = cfi->cfi_container; |
| 111 | |
Al Viro | 72c2d53 | 2013-09-22 16:27:52 -0400 | [diff] [blame] | 112 | if (!host_file->f_op->mmap) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | return -ENODEV; |
| 114 | |
Jan Harkes | c93b747 | 2019-07-16 16:28:04 -0700 | [diff] [blame] | 115 | if (WARN_ON(coda_file != vma->vm_file)) |
| 116 | return -EIO; |
| 117 | |
| 118 | cvm_ops = kmalloc(sizeof(struct coda_vm_ops), GFP_KERNEL); |
| 119 | if (!cvm_ops) |
| 120 | return -ENOMEM; |
| 121 | |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 122 | coda_inode = file_inode(coda_file); |
| 123 | host_inode = file_inode(host_file); |
Yoshihisa Abe | b5ce1d8 | 2010-10-25 02:03:44 -0400 | [diff] [blame] | 124 | |
| 125 | cii = ITOC(coda_inode); |
| 126 | spin_lock(&cii->c_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | coda_file->f_mapping = host_file->f_mapping; |
| 128 | if (coda_inode->i_mapping == &coda_inode->i_data) |
| 129 | coda_inode->i_mapping = host_inode->i_mapping; |
| 130 | |
| 131 | /* only allow additional mmaps as long as userspace isn't changing |
| 132 | * the container file on us! */ |
Yoshihisa Abe | b5ce1d8 | 2010-10-25 02:03:44 -0400 | [diff] [blame] | 133 | else if (coda_inode->i_mapping != host_inode->i_mapping) { |
| 134 | spin_unlock(&cii->c_lock); |
Jan Harkes | c93b747 | 2019-07-16 16:28:04 -0700 | [diff] [blame] | 135 | kfree(cvm_ops); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | return -EBUSY; |
Yoshihisa Abe | b5ce1d8 | 2010-10-25 02:03:44 -0400 | [diff] [blame] | 137 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | |
| 139 | /* keep track of how often the coda_inode/host_file has been mmapped */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | cii->c_mapcount++; |
| 141 | cfi->cfi_mapcount++; |
Yoshihisa Abe | b5ce1d8 | 2010-10-25 02:03:44 -0400 | [diff] [blame] | 142 | spin_unlock(&cii->c_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | |
Jan Harkes | c93b747 | 2019-07-16 16:28:04 -0700 | [diff] [blame] | 144 | vma->vm_file = get_file(host_file); |
| 145 | ret = host_file->f_op->mmap(host_file, vma); |
| 146 | |
| 147 | if (ret) { |
| 148 | /* if call_mmap fails, our caller will put coda_file so we |
| 149 | * should drop the reference to the host_file that we got. |
| 150 | */ |
| 151 | fput(host_file); |
| 152 | kfree(cvm_ops); |
| 153 | } else { |
| 154 | /* here we add redirects for the open/close vm_operations */ |
| 155 | cvm_ops->host_vm_ops = vma->vm_ops; |
| 156 | if (vma->vm_ops) |
| 157 | cvm_ops->vm_ops = *vma->vm_ops; |
| 158 | |
| 159 | cvm_ops->vm_ops.open = coda_vm_open; |
| 160 | cvm_ops->vm_ops.close = coda_vm_close; |
| 161 | cvm_ops->coda_file = coda_file; |
| 162 | atomic_set(&cvm_ops->refcnt, 1); |
| 163 | |
| 164 | vma->vm_ops = &cvm_ops->vm_ops; |
| 165 | } |
| 166 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | } |
| 168 | |
| 169 | int coda_open(struct inode *coda_inode, struct file *coda_file) |
| 170 | { |
| 171 | struct file *host_file = NULL; |
| 172 | int error; |
| 173 | unsigned short flags = coda_file->f_flags & (~O_EXCL); |
| 174 | unsigned short coda_flags = coda_flags_to_cflags(flags); |
| 175 | struct coda_file_info *cfi; |
| 176 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL); |
Josh Triplett | 6ecbc4e | 2006-07-30 03:03:56 -0700 | [diff] [blame] | 178 | if (!cfi) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags, |
Jan Harkes | 38c2e43 | 2007-07-19 01:48:41 -0700 | [diff] [blame] | 182 | &host_file); |
| 183 | if (!host_file) |
| 184 | error = -EIO; |
| 185 | |
| 186 | if (error) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | kfree(cfi); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | return error; |
| 189 | } |
| 190 | |
| 191 | host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC); |
| 192 | |
| 193 | cfi->cfi_magic = CODA_MAGIC; |
| 194 | cfi->cfi_mapcount = 0; |
| 195 | cfi->cfi_container = host_file; |
| 196 | |
| 197 | BUG_ON(coda_file->private_data != NULL); |
| 198 | coda_file->private_data = cfi; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | return 0; |
| 200 | } |
| 201 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | int coda_release(struct inode *coda_inode, struct file *coda_file) |
| 203 | { |
| 204 | unsigned short flags = (coda_file->f_flags) & (~O_EXCL); |
| 205 | unsigned short coda_flags = coda_flags_to_cflags(flags); |
| 206 | struct coda_file_info *cfi; |
| 207 | struct coda_inode_info *cii; |
| 208 | struct inode *host_inode; |
Yoshihisa Abe | f7cc02b8 | 2010-10-25 02:03:45 -0400 | [diff] [blame] | 209 | int err; |
Jan Harkes | 3cf01f2 | 2007-07-19 01:48:51 -0700 | [diff] [blame] | 210 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 211 | cfi = CODA_FTOC(coda_file); |
| 212 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); |
| 213 | |
Jan Harkes | d3fec42 | 2007-07-21 04:37:26 -0700 | [diff] [blame] | 214 | err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode), |
David Howells | d76b0d9 | 2008-11-14 10:39:25 +1100 | [diff] [blame] | 215 | coda_flags, coda_file->f_cred->fsuid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 217 | host_inode = file_inode(cfi->cfi_container); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | cii = ITOC(coda_inode); |
| 219 | |
| 220 | /* did we mmap this file? */ |
Yoshihisa Abe | b5ce1d8 | 2010-10-25 02:03:44 -0400 | [diff] [blame] | 221 | spin_lock(&cii->c_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | if (coda_inode->i_mapping == &host_inode->i_data) { |
| 223 | cii->c_mapcount -= cfi->cfi_mapcount; |
| 224 | if (!cii->c_mapcount) |
| 225 | coda_inode->i_mapping = &coda_inode->i_data; |
| 226 | } |
Yoshihisa Abe | b5ce1d8 | 2010-10-25 02:03:44 -0400 | [diff] [blame] | 227 | spin_unlock(&cii->c_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | |
| 229 | fput(cfi->cfi_container); |
| 230 | kfree(coda_file->private_data); |
| 231 | coda_file->private_data = NULL; |
| 232 | |
Jan Harkes | d3fec42 | 2007-07-21 04:37:26 -0700 | [diff] [blame] | 233 | /* VFS fput ignores the return value from file_operations->release, so |
| 234 | * there is no use returning an error here */ |
| 235 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | } |
| 237 | |
Josef Bacik | 02c24a8 | 2011-07-16 20:44:56 -0400 | [diff] [blame] | 238 | int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | { |
| 240 | struct file *host_file; |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 241 | struct inode *coda_inode = file_inode(coda_file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | struct coda_file_info *cfi; |
Yoshihisa Abe | f7cc02b8 | 2010-10-25 02:03:45 -0400 | [diff] [blame] | 243 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 244 | |
| 245 | if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) || |
| 246 | S_ISLNK(coda_inode->i_mode))) |
| 247 | return -EINVAL; |
| 248 | |
Josef Bacik | 02c24a8 | 2011-07-16 20:44:56 -0400 | [diff] [blame] | 249 | err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end); |
| 250 | if (err) |
| 251 | return err; |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 252 | inode_lock(coda_inode); |
Josef Bacik | 02c24a8 | 2011-07-16 20:44:56 -0400 | [diff] [blame] | 253 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 254 | cfi = CODA_FTOC(coda_file); |
| 255 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); |
| 256 | host_file = cfi->cfi_container; |
| 257 | |
Christoph Hellwig | 8018ab0 | 2010-03-22 17:32:25 +0100 | [diff] [blame] | 258 | err = vfs_fsync(host_file, datasync); |
Yoshihisa Abe | f7cc02b8 | 2010-10-25 02:03:45 -0400 | [diff] [blame] | 259 | if (!err && !datasync) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode)); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 261 | inode_unlock(coda_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | |
| 263 | return err; |
| 264 | } |
| 265 | |
Arjan van de Ven | 4b6f5d2 | 2006-03-28 01:56:42 -0800 | [diff] [blame] | 266 | const struct file_operations coda_file_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | .llseek = generic_file_llseek, |
Al Viro | c12c49e | 2015-04-03 10:58:11 -0400 | [diff] [blame] | 268 | .read_iter = coda_file_read_iter, |
| 269 | .write_iter = coda_file_write_iter, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | .mmap = coda_file_mmap, |
| 271 | .open = coda_open, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | .release = coda_release, |
| 273 | .fsync = coda_fsync, |
Al Viro | 82c156f | 2016-09-22 23:35:42 -0400 | [diff] [blame] | 274 | .splice_read = generic_file_splice_read, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | }; |
| 276 | |