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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 | /* * linux/fs/nfs/file.c * * Copyright (C) 1992 Rick Sladkey * * Changes Copyright (C) 1994 by Florian La Roche * - Do not copy data too often around in the kernel. * - In nfs_file_read the return value of kmalloc wasn't checked. * - Put in a better version of read look-ahead buffering. Original idea * and implementation by Wai S Kok elekokws@ee.nus.sg. * * Expire cache on write to a file by Wai S Kok (Oct 1994). * * Total rewrite of read side for new NFS buffer cache.. Linus. * * nfs regular file handling functions */ #include <linux/sched.h> #include <linux/kernel.h> #include <linux/errno.h> #include <linux/fcntl.h> #include <linux/stat.h> #include <linux/nfs_fs.h> #include <linux/mm.h> #include <linux/malloc.h> #include <linux/pagemap.h> #include <linux/lockd/bind.h> #include <asm/segment.h> #include <asm/system.h> #define NFSDBG_FACILITY NFSDBG_FILE static int nfs_file_mmap(struct inode *, struct file *, struct vm_area_struct *); static long nfs_file_read(struct inode *, struct file *, char *, unsigned long); static long nfs_file_write(struct inode *, struct file *, const char *, unsigned long); static int nfs_file_close(struct inode *, struct file *); static int nfs_fsync(struct inode *, struct file *); static struct file_operations nfs_file_operations = { NULL, /* lseek - default */ nfs_file_read, /* read */ nfs_file_write, /* write */ NULL, /* readdir - bad */ NULL, /* select - default */ NULL, /* ioctl - default */ nfs_file_mmap, /* mmap */ NULL, /* no special open is needed */ nfs_file_close, /* release */ nfs_fsync, /* fsync */ NULL, /* fasync */ NULL, /* check_media_change */ NULL, /* revalidate */ nfs_lock, /* lock */ }; struct inode_operations nfs_file_inode_operations = { &nfs_file_operations, /* default file operations */ NULL, /* create */ NULL, /* lookup */ NULL, /* link */ NULL, /* unlink */ NULL, /* symlink */ NULL, /* mkdir */ NULL, /* rmdir */ NULL, /* mknod */ NULL, /* rename */ NULL, /* readlink */ nfs_readpage, /* readpage */ nfs_writepage, /* writepage */ NULL, /* bmap */ NULL, /* truncate */ NULL, /* permission */ NULL, /* smap */ nfs_updatepage, /* updatepage */ nfs_revalidate, /* revalidate */ }; /* Hack for future NFS swap support */ #ifndef IS_SWAPFILE # define IS_SWAPFILE(inode) (0) #endif static int nfs_file_close(struct inode *inode, struct file *file) { int status; dfprintk(VFS, "nfs: close(%x/%ld)\n", inode->i_dev, inode->i_ino); if ((status = nfs_flush_dirty_pages(inode, 0, 0)) < 0) return status; return nfs_write_error(inode); } static long nfs_file_read(struct inode * inode, struct file * file, char * buf, unsigned long count) { int status; dfprintk(VFS, "nfs: read(%x/%ld, %lu@%lu)\n", inode->i_dev, inode->i_ino, count, (unsigned long) file->f_pos); if ((status = nfs_revalidate_inode(NFS_SERVER(inode), inode)) < 0) return status; return generic_file_read(inode, file, buf, count); } static int nfs_file_mmap(struct inode * inode, struct file * file, struct vm_area_struct * vma) { int status; dfprintk(VFS, "nfs: mmap(%x/%ld)\n", inode->i_dev, inode->i_ino); if ((status = nfs_revalidate_inode(NFS_SERVER(inode), inode)) < 0) return status; return generic_file_mmap(inode, file, vma); } static int nfs_fsync(struct inode *inode, struct file *file) { dfprintk(VFS, "nfs: fsync(%x/%ld)\n", inode->i_dev, inode->i_ino); return nfs_flush_dirty_pages(inode, 0, 0); } /* * Write to a file (through the page cache). */ static long nfs_file_write(struct inode *inode, struct file *file, const char *buf, unsigned long count) { int result; dfprintk(VFS, "nfs: write(%x/%ld (%d), %lu@%lu)\n", inode->i_dev, inode->i_ino, atomic_read(&inode->i_count), count, (unsigned long) file->f_pos); if (!inode) { printk("nfs_file_write: inode = NULL\n"); return -EINVAL; } if (IS_SWAPFILE(inode)) { printk("NFS: attempt to write to active swap file!\n"); return -EBUSY; } if ((result = nfs_revalidate_inode(NFS_SERVER(inode), inode)) < 0) return result; if (!S_ISREG(inode->i_mode)) { printk("nfs_file_write: write to non-file, mode %07o\n", inode->i_mode); return -EINVAL; } if (count <= 0) return 0; /* Return error from previous async call */ if ((result = nfs_write_error(inode)) < 0) return result; return generic_file_write(inode, file, buf, count); } /* * Lock a (portion of) a file */ int nfs_lock(struct inode *inode, struct file *filp, int cmd, struct file_lock *fl) { int status; dprintk("NFS: nfs_lock(f=%4x/%ld, t=%x, fl=%x, r=%ld:%ld)\n", filp->f_inode->i_dev, filp->f_inode->i_ino, fl->fl_type, fl->fl_flags, fl->fl_start, fl->fl_end); if (!(inode = filp->f_inode)) return -EINVAL; /* No mandatory locks over NFS */ if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID) return -ENOLCK; /* Fake OK code if mounted without NLM support */ if (NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM) return 0; /* * No BSD flocks over NFS allowed. * Note: we could try to fake a POSIX lock request here by * using ((u32) filp | 0x80000000) or some such as the pid. * Not sure whether that would be unique, though, or whether * that would break in other places. */ if (!fl->fl_owner || (fl->fl_flags & (FL_POSIX|FL_BROKEN)) != FL_POSIX) return -ENOLCK; /* If unlocking a file region, flush dirty pages (unless we've * been killed by a signal, that is). */ if (cmd == F_SETLK && fl->fl_type == F_UNLCK && !(current->signal & ~current->blocked)) { status = nfs_flush_dirty_pages(inode, fl->fl_start, fl->fl_end == NLM_OFFSET_MAX? 0 : fl->fl_end - fl->fl_start + 1); if (status < 0) return status; } if ((status = nlmclnt_proc(inode, cmd, fl)) < 0) return status; /* Here, we could turn off write-back of pages in the * locked file region */ return 0; } |