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 vfs_fsync(file, 0); 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 (file_inode(file_in) == file_inode(file_out)) 137 return -EINVAL; 138 139 return nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count); 140 } 141 142 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence) 143 { 144 loff_t ret; 145 146 switch (whence) { 147 case SEEK_HOLE: 148 case SEEK_DATA: 149 ret = nfs42_proc_llseek(filep, offset, whence); 150 if (ret != -ENOTSUPP) 151 return ret; 152 default: 153 return nfs_file_llseek(filep, offset, whence); 154 } 155 } 156 157 static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len) 158 { 159 struct inode *inode = file_inode(filep); 160 long ret; 161 162 if (!S_ISREG(inode->i_mode)) 163 return -EOPNOTSUPP; 164 165 if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE))) 166 return -EOPNOTSUPP; 167 168 ret = inode_newsize_ok(inode, offset + len); 169 if (ret < 0) 170 return ret; 171 172 if (mode & FALLOC_FL_PUNCH_HOLE) 173 return nfs42_proc_deallocate(filep, offset, len); 174 return nfs42_proc_allocate(filep, offset, len); 175 } 176 177 static int nfs42_clone_file_range(struct file *src_file, loff_t src_off, 178 struct file *dst_file, loff_t dst_off, u64 count) 179 { 180 struct inode *dst_inode = file_inode(dst_file); 181 struct nfs_server *server = NFS_SERVER(dst_inode); 182 struct inode *src_inode = file_inode(src_file); 183 unsigned int bs = server->clone_blksize; 184 bool same_inode = false; 185 int ret; 186 187 /* check alignment w.r.t. clone_blksize */ 188 ret = -EINVAL; 189 if (bs) { 190 if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs)) 191 goto out; 192 if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count)) 193 goto out; 194 } 195 196 if (src_inode == dst_inode) 197 same_inode = true; 198 199 /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */ 200 if (same_inode) { 201 inode_lock(src_inode); 202 } else if (dst_inode < src_inode) { 203 inode_lock_nested(dst_inode, I_MUTEX_PARENT); 204 inode_lock_nested(src_inode, I_MUTEX_CHILD); 205 } else { 206 inode_lock_nested(src_inode, I_MUTEX_PARENT); 207 inode_lock_nested(dst_inode, I_MUTEX_CHILD); 208 } 209 210 /* flush all pending writes on both src and dst so that server 211 * has the latest data */ 212 ret = nfs_sync_inode(src_inode); 213 if (ret) 214 goto out_unlock; 215 ret = nfs_sync_inode(dst_inode); 216 if (ret) 217 goto out_unlock; 218 219 ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count); 220 221 /* truncate inode page cache of the dst range so that future reads can fetch 222 * new data from server */ 223 if (!ret) 224 truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1); 225 226 out_unlock: 227 if (same_inode) { 228 inode_unlock(src_inode); 229 } else if (dst_inode < src_inode) { 230 inode_unlock(src_inode); 231 inode_unlock(dst_inode); 232 } else { 233 inode_unlock(dst_inode); 234 inode_unlock(src_inode); 235 } 236 out: 237 return ret; 238 } 239 #endif /* CONFIG_NFS_V4_2 */ 240 241 const struct file_operations nfs4_file_operations = { 242 .read_iter = nfs_file_read, 243 .write_iter = nfs_file_write, 244 .mmap = nfs_file_mmap, 245 .open = nfs4_file_open, 246 .flush = nfs4_file_flush, 247 .release = nfs_file_release, 248 .fsync = nfs_file_fsync, 249 .lock = nfs_lock, 250 .flock = nfs_flock, 251 .splice_read = generic_file_splice_read, 252 .splice_write = iter_file_splice_write, 253 .check_flags = nfs_check_flags, 254 .setlease = simple_nosetlease, 255 #ifdef CONFIG_NFS_V4_2 256 .copy_file_range = nfs4_copy_file_range, 257 .llseek = nfs4_file_llseek, 258 .fallocate = nfs42_fallocate, 259 .clone_file_range = nfs42_clone_file_range, 260 #else 261 .llseek = nfs_file_llseek, 262 #endif 263 }; 264