1 /* 2 * linux/fs/nfs/file.c 3 * 4 * Copyright (C) 1992 Rick Sladkey 5 */ 6 #include <linux/fs.h> 7 #include <linux/file.h> 8 #include <linux/falloc.h> 9 #include <linux/nfs_fs.h> 10 #include <uapi/linux/btrfs.h> /* BTRFS_IOC_CLONE/BTRFS_IOC_CLONE_RANGE */ 11 #include "delegation.h" 12 #include "internal.h" 13 #include "iostat.h" 14 #include "fscache.h" 15 #include "pnfs.h" 16 17 #include "nfstrace.h" 18 19 #ifdef CONFIG_NFS_V4_2 20 #include "nfs42.h" 21 #endif 22 23 #define NFSDBG_FACILITY NFSDBG_FILE 24 25 static int 26 nfs4_file_open(struct inode *inode, struct file *filp) 27 { 28 struct nfs_open_context *ctx; 29 struct dentry *dentry = filp->f_path.dentry; 30 struct dentry *parent = NULL; 31 struct inode *dir; 32 unsigned openflags = filp->f_flags; 33 struct iattr attr; 34 int err; 35 36 /* 37 * If no cached dentry exists or if it's negative, NFSv4 handled the 38 * opens in ->lookup() or ->create(). 39 * 40 * We only get this far for a cached positive dentry. We skipped 41 * revalidation, so handle it here by dropping the dentry and returning 42 * -EOPENSTALE. The VFS will retry the lookup/create/open. 43 */ 44 45 dprintk("NFS: open file(%pd2)\n", dentry); 46 47 err = nfs_check_flags(openflags); 48 if (err) 49 return err; 50 51 if ((openflags & O_ACCMODE) == 3) 52 openflags--; 53 54 /* We can't create new files here */ 55 openflags &= ~(O_CREAT|O_EXCL); 56 57 parent = dget_parent(dentry); 58 dir = d_inode(parent); 59 60 ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode); 61 err = PTR_ERR(ctx); 62 if (IS_ERR(ctx)) 63 goto out; 64 65 attr.ia_valid = ATTR_OPEN; 66 if (openflags & O_TRUNC) { 67 attr.ia_valid |= ATTR_SIZE; 68 attr.ia_size = 0; 69 nfs_sync_inode(inode); 70 } 71 72 inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, NULL); 73 if (IS_ERR(inode)) { 74 err = PTR_ERR(inode); 75 switch (err) { 76 case -EPERM: 77 case -EACCES: 78 case -EDQUOT: 79 case -ENOSPC: 80 case -EROFS: 81 goto out_put_ctx; 82 default: 83 goto out_drop; 84 } 85 } 86 if (inode != d_inode(dentry)) 87 goto out_drop; 88 89 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 90 nfs_file_set_open_context(filp, ctx); 91 nfs_fscache_open_file(inode, filp); 92 err = 0; 93 94 out_put_ctx: 95 put_nfs_open_context(ctx); 96 out: 97 dput(parent); 98 return err; 99 100 out_drop: 101 d_drop(dentry); 102 err = -EOPENSTALE; 103 goto out_put_ctx; 104 } 105 106 /* 107 * Flush all dirty pages, and check for write errors. 108 */ 109 static int 110 nfs4_file_flush(struct file *file, fl_owner_t id) 111 { 112 struct inode *inode = file_inode(file); 113 114 dprintk("NFS: flush(%pD2)\n", file); 115 116 nfs_inc_stats(inode, NFSIOS_VFSFLUSH); 117 if ((file->f_mode & FMODE_WRITE) == 0) 118 return 0; 119 120 /* 121 * If we're holding a write delegation, then check if we're required 122 * to flush the i/o on close. If not, then just start the i/o now. 123 */ 124 if (!nfs4_delegation_flush_on_close(inode)) 125 return filemap_fdatawrite(file->f_mapping); 126 127 /* Flush writes to the server and return any errors */ 128 return vfs_fsync(file, 0); 129 } 130 131 static int 132 nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync) 133 { 134 int ret; 135 struct inode *inode = file_inode(file); 136 137 trace_nfs_fsync_enter(inode); 138 139 nfs_inode_dio_wait(inode); 140 do { 141 ret = filemap_write_and_wait_range(inode->i_mapping, start, end); 142 if (ret != 0) 143 break; 144 inode_lock(inode); 145 ret = nfs_file_fsync_commit(file, start, end, datasync); 146 if (!ret) 147 ret = pnfs_sync_inode(inode, !!datasync); 148 inode_unlock(inode); 149 /* 150 * If nfs_file_fsync_commit detected a server reboot, then 151 * resend all dirty pages that might have been covered by 152 * the NFS_CONTEXT_RESEND_WRITES flag 153 */ 154 start = 0; 155 end = LLONG_MAX; 156 } while (ret == -EAGAIN); 157 158 trace_nfs_fsync_exit(inode, ret); 159 return ret; 160 } 161 162 #ifdef CONFIG_NFS_V4_2 163 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence) 164 { 165 loff_t ret; 166 167 switch (whence) { 168 case SEEK_HOLE: 169 case SEEK_DATA: 170 ret = nfs42_proc_llseek(filep, offset, whence); 171 if (ret != -ENOTSUPP) 172 return ret; 173 default: 174 return nfs_file_llseek(filep, offset, whence); 175 } 176 } 177 178 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len) 179 { 180 struct inode *inode = file_inode(filep); 181 long ret; 182 183 if (!S_ISREG(inode->i_mode)) 184 return -EOPNOTSUPP; 185 186 if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE))) 187 return -EOPNOTSUPP; 188 189 ret = inode_newsize_ok(inode, offset + len); 190 if (ret < 0) 191 return ret; 192 193 if (mode & FALLOC_FL_PUNCH_HOLE) 194 return nfs42_proc_deallocate(filep, offset, len); 195 return nfs42_proc_allocate(filep, offset, len); 196 } 197 198 static int nfs42_clone_file_range(struct file *src_file, loff_t src_off, 199 struct file *dst_file, loff_t dst_off, u64 count) 200 { 201 struct inode *dst_inode = file_inode(dst_file); 202 struct nfs_server *server = NFS_SERVER(dst_inode); 203 struct inode *src_inode = file_inode(src_file); 204 unsigned int bs = server->clone_blksize; 205 bool same_inode = false; 206 int ret; 207 208 /* check alignment w.r.t. clone_blksize */ 209 ret = -EINVAL; 210 if (bs) { 211 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs)) 212 goto out; 213 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count)) 214 goto out; 215 } 216 217 if (src_inode == dst_inode) 218 same_inode = true; 219 220 /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */ 221 if (same_inode) { 222 inode_lock(src_inode); 223 } else if (dst_inode < src_inode) { 224 inode_lock_nested(dst_inode, I_MUTEX_PARENT); 225 inode_lock_nested(src_inode, I_MUTEX_CHILD); 226 } else { 227 inode_lock_nested(src_inode, I_MUTEX_PARENT); 228 inode_lock_nested(dst_inode, I_MUTEX_CHILD); 229 } 230 231 /* flush all pending writes on both src and dst so that server 232 * has the latest data */ 233 ret = nfs_sync_inode(src_inode); 234 if (ret) 235 goto out_unlock; 236 ret = nfs_sync_inode(dst_inode); 237 if (ret) 238 goto out_unlock; 239 240 ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count); 241 242 /* truncate inode page cache of the dst range so that future reads can fetch 243 * new data from server */ 244 if (!ret) 245 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1); 246 247 out_unlock: 248 if (same_inode) { 249 inode_unlock(src_inode); 250 } else if (dst_inode < src_inode) { 251 inode_unlock(src_inode); 252 inode_unlock(dst_inode); 253 } else { 254 inode_unlock(dst_inode); 255 inode_unlock(src_inode); 256 } 257 out: 258 return ret; 259 } 260 #endif /* CONFIG_NFS_V4_2 */ 261 262 const struct file_operations nfs4_file_operations = { 263 .read_iter = nfs_file_read, 264 .write_iter = nfs_file_write, 265 .mmap = nfs_file_mmap, 266 .open = nfs4_file_open, 267 .flush = nfs4_file_flush, 268 .release = nfs_file_release, 269 .fsync = nfs4_file_fsync, 270 .lock = nfs_lock, 271 .flock = nfs_flock, 272 .splice_read = nfs_file_splice_read, 273 .splice_write = iter_file_splice_write, 274 .check_flags = nfs_check_flags, 275 .setlease = simple_nosetlease, 276 #ifdef CONFIG_NFS_V4_2 277 .llseek = nfs4_file_llseek, 278 .fallocate = nfs42_fallocate, 279 .clone_file_range = nfs42_clone_file_range, 280 #else 281 .llseek = nfs_file_llseek, 282 #endif 283 }; 284