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 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(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 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 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 if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY)) 137 return -EOPNOTSUPP; 138 if (file_inode(file_in) == file_inode(file_out)) 139 return -EOPNOTSUPP; 140 return nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count); 141 } 142 143 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence) 144 { 145 loff_t ret; 146 147 switch (whence) { 148 case SEEK_HOLE: 149 case SEEK_DATA: 150 ret = nfs42_proc_llseek(filep, offset, whence); 151 if (ret != -ENOTSUPP) 152 return ret; 153 /* Fall through */ 154 default: 155 return nfs_file_llseek(filep, offset, whence); 156 } 157 } 158 159 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len) 160 { 161 struct inode *inode = file_inode(filep); 162 long ret; 163 164 if (!S_ISREG(inode->i_mode)) 165 return -EOPNOTSUPP; 166 167 if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE))) 168 return -EOPNOTSUPP; 169 170 ret = inode_newsize_ok(inode, offset + len); 171 if (ret < 0) 172 return ret; 173 174 if (mode & FALLOC_FL_PUNCH_HOLE) 175 return nfs42_proc_deallocate(filep, offset, len); 176 return nfs42_proc_allocate(filep, offset, len); 177 } 178 179 static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off, 180 struct file *dst_file, loff_t dst_off, loff_t count, 181 unsigned int remap_flags) 182 { 183 struct inode *dst_inode = file_inode(dst_file); 184 struct nfs_server *server = NFS_SERVER(dst_inode); 185 struct inode *src_inode = file_inode(src_file); 186 unsigned int bs = server->clone_blksize; 187 bool same_inode = false; 188 int ret; 189 190 if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY)) 191 return -EINVAL; 192 193 /* check alignment w.r.t. clone_blksize */ 194 ret = -EINVAL; 195 if (bs) { 196 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs)) 197 goto out; 198 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count)) 199 goto out; 200 } 201 202 if (src_inode == dst_inode) 203 same_inode = true; 204 205 /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */ 206 if (same_inode) { 207 inode_lock(src_inode); 208 } else if (dst_inode < src_inode) { 209 inode_lock_nested(dst_inode, I_MUTEX_PARENT); 210 inode_lock_nested(src_inode, I_MUTEX_CHILD); 211 } else { 212 inode_lock_nested(src_inode, I_MUTEX_PARENT); 213 inode_lock_nested(dst_inode, I_MUTEX_CHILD); 214 } 215 216 /* flush all pending writes on both src and dst so that server 217 * has the latest data */ 218 ret = nfs_sync_inode(src_inode); 219 if (ret) 220 goto out_unlock; 221 ret = nfs_sync_inode(dst_inode); 222 if (ret) 223 goto out_unlock; 224 225 ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count); 226 227 /* truncate inode page cache of the dst range so that future reads can fetch 228 * new data from server */ 229 if (!ret) 230 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1); 231 232 out_unlock: 233 if (same_inode) { 234 inode_unlock(src_inode); 235 } else if (dst_inode < src_inode) { 236 inode_unlock(src_inode); 237 inode_unlock(dst_inode); 238 } else { 239 inode_unlock(dst_inode); 240 inode_unlock(src_inode); 241 } 242 out: 243 return ret < 0 ? ret : count; 244 } 245 #endif /* CONFIG_NFS_V4_2 */ 246 247 const struct file_operations nfs4_file_operations = { 248 .read_iter = nfs_file_read, 249 .write_iter = nfs_file_write, 250 .mmap = nfs_file_mmap, 251 .open = nfs4_file_open, 252 .flush = nfs4_file_flush, 253 .release = nfs_file_release, 254 .fsync = nfs_file_fsync, 255 .lock = nfs_lock, 256 .flock = nfs_flock, 257 .splice_read = generic_file_splice_read, 258 .splice_write = iter_file_splice_write, 259 .check_flags = nfs_check_flags, 260 .setlease = simple_nosetlease, 261 #ifdef CONFIG_NFS_V4_2 262 .copy_file_range = nfs4_copy_file_range, 263 .llseek = nfs4_file_llseek, 264 .fallocate = nfs42_fallocate, 265 .remap_file_range = nfs42_remap_file_range, 266 #else 267 .llseek = nfs_file_llseek, 268 #endif 269 }; 270