1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/nfs/file.c 4 * 5 * Copyright (C) 1992 Rick Sladkey 6 */ 7 #include <linux/fs.h> 8 #include <linux/file.h> 9 #include <linux/falloc.h> 10 #include <linux/nfs_fs.h> 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 = file_dentry(filp); 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 return nfs_open(inode, filp); 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(file_dentry(filp), filp->f_mode, filp); 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 filemap_write_and_wait(inode->i_mapping); 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 default: 77 goto out_put_ctx; 78 case -ENOENT: 79 case -ESTALE: 80 case -EISDIR: 81 case -ENOTDIR: 82 case -ELOOP: 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 nfs_wb_all(inode); 129 } 130 131 #ifdef CONFIG_NFS_V4_2 132 static ssize_t __nfs4_copy_file_range(struct file *file_in, loff_t pos_in, 133 struct file *file_out, loff_t pos_out, 134 size_t count, unsigned int flags) 135 { 136 /* Only offload copy if superblock is the same */ 137 if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb) 138 return -EXDEV; 139 if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY)) 140 return -EOPNOTSUPP; 141 if (file_inode(file_in) == file_inode(file_out)) 142 return -EOPNOTSUPP; 143 return nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count); 144 } 145 146 static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in, 147 struct file *file_out, loff_t pos_out, 148 size_t count, unsigned int flags) 149 { 150 ssize_t ret; 151 152 ret = __nfs4_copy_file_range(file_in, pos_in, file_out, pos_out, count, 153 flags); 154 if (ret == -EOPNOTSUPP || ret == -EXDEV) 155 ret = generic_copy_file_range(file_in, pos_in, file_out, 156 pos_out, count, flags); 157 return ret; 158 } 159 160 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence) 161 { 162 loff_t ret; 163 164 switch (whence) { 165 case SEEK_HOLE: 166 case SEEK_DATA: 167 ret = nfs42_proc_llseek(filep, offset, whence); 168 if (ret != -ENOTSUPP) 169 return ret; 170 /* Fall through */ 171 default: 172 return nfs_file_llseek(filep, offset, whence); 173 } 174 } 175 176 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len) 177 { 178 struct inode *inode = file_inode(filep); 179 long ret; 180 181 if (!S_ISREG(inode->i_mode)) 182 return -EOPNOTSUPP; 183 184 if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE))) 185 return -EOPNOTSUPP; 186 187 ret = inode_newsize_ok(inode, offset + len); 188 if (ret < 0) 189 return ret; 190 191 if (mode & FALLOC_FL_PUNCH_HOLE) 192 return nfs42_proc_deallocate(filep, offset, len); 193 return nfs42_proc_allocate(filep, offset, len); 194 } 195 196 static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off, 197 struct file *dst_file, loff_t dst_off, loff_t count, 198 unsigned int remap_flags) 199 { 200 struct inode *dst_inode = file_inode(dst_file); 201 struct nfs_server *server = NFS_SERVER(dst_inode); 202 struct inode *src_inode = file_inode(src_file); 203 unsigned int bs = server->clone_blksize; 204 bool same_inode = false; 205 int ret; 206 207 /* NFS does not support deduplication. */ 208 if (remap_flags & REMAP_FILE_DEDUP) 209 return -EOPNOTSUPP; 210 211 if (remap_flags & ~REMAP_FILE_ADVISORY) 212 return -EINVAL; 213 214 /* check alignment w.r.t. clone_blksize */ 215 ret = -EINVAL; 216 if (bs) { 217 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs)) 218 goto out; 219 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count)) 220 goto out; 221 } 222 223 if (src_inode == dst_inode) 224 same_inode = true; 225 226 /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */ 227 if (same_inode) { 228 inode_lock(src_inode); 229 } else if (dst_inode < src_inode) { 230 inode_lock_nested(dst_inode, I_MUTEX_PARENT); 231 inode_lock_nested(src_inode, I_MUTEX_CHILD); 232 } else { 233 inode_lock_nested(src_inode, I_MUTEX_PARENT); 234 inode_lock_nested(dst_inode, I_MUTEX_CHILD); 235 } 236 237 /* flush all pending writes on both src and dst so that server 238 * has the latest data */ 239 ret = nfs_sync_inode(src_inode); 240 if (ret) 241 goto out_unlock; 242 ret = nfs_sync_inode(dst_inode); 243 if (ret) 244 goto out_unlock; 245 246 ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count); 247 248 /* truncate inode page cache of the dst range so that future reads can fetch 249 * new data from server */ 250 if (!ret) 251 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1); 252 253 out_unlock: 254 if (same_inode) { 255 inode_unlock(src_inode); 256 } else if (dst_inode < src_inode) { 257 inode_unlock(src_inode); 258 inode_unlock(dst_inode); 259 } else { 260 inode_unlock(dst_inode); 261 inode_unlock(src_inode); 262 } 263 out: 264 return ret < 0 ? ret : count; 265 } 266 #endif /* CONFIG_NFS_V4_2 */ 267 268 const struct file_operations nfs4_file_operations = { 269 .read_iter = nfs_file_read, 270 .write_iter = nfs_file_write, 271 .mmap = nfs_file_mmap, 272 .open = nfs4_file_open, 273 .flush = nfs4_file_flush, 274 .release = nfs_file_release, 275 .fsync = nfs_file_fsync, 276 .lock = nfs_lock, 277 .flock = nfs_flock, 278 .splice_read = generic_file_splice_read, 279 .splice_write = iter_file_splice_write, 280 .check_flags = nfs_check_flags, 281 .setlease = simple_nosetlease, 282 #ifdef CONFIG_NFS_V4_2 283 .copy_file_range = nfs4_copy_file_range, 284 .llseek = nfs4_file_llseek, 285 .fallocate = nfs42_fallocate, 286 .remap_file_range = nfs42_remap_file_range, 287 #else 288 .llseek = nfs_file_llseek, 289 #endif 290 }; 291