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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 | /* * 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/mm.h> #include <linux/nfs_fs.h> #include <linux/malloc.h> #include <linux/pagemap.h> #include <asm/segment.h> #include <asm/system.h> static int nfs_file_mmap(struct inode *, struct file *, struct vm_area_struct *); static int nfs_file_read(struct inode *, struct file *, char *, int); static int nfs_file_write(struct inode *, struct file *, const char *, int); 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 */ NULL, /* release */ nfs_fsync, /* fsync */ }; 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 */ NULL, /* follow_link */ nfs_readpage, /* readpage */ NULL, /* writepage */ NULL, /* bmap */ NULL /* truncate */ }; static inline void revalidate_inode(struct nfs_server * server, struct inode * inode) { struct nfs_fattr fattr; if (jiffies - NFS_READTIME(inode) < NFS_ATTRTIMEO(inode)) return; NFS_READTIME(inode) = jiffies; if (nfs_proc_getattr(server, NFS_FH(inode), &fattr) == 0) { nfs_refresh_inode(inode, &fattr); if (fattr.mtime.seconds == NFS_OLDMTIME(inode)) { if ((NFS_ATTRTIMEO(inode) <<= 1) > server->acregmax) NFS_ATTRTIMEO(inode) = server->acregmax; return; } NFS_OLDMTIME(inode) = fattr.mtime.seconds; } invalidate_inode_pages(inode); } static int nfs_file_read(struct inode * inode, struct file * file, char * buf, int count) { revalidate_inode(NFS_SERVER(inode), inode); return generic_file_read(inode, file, buf, count); } static int nfs_file_mmap(struct inode * inode, struct file * file, struct vm_area_struct * vma) { revalidate_inode(NFS_SERVER(inode), inode); return generic_file_mmap(inode, file, vma); } static int nfs_fsync(struct inode *inode, struct file *file) { return 0; } static int nfs_file_write(struct inode *inode, struct file *file, const char *buf, int count) { int result, written, wsize; struct nfs_fattr fattr; unsigned long pos; if (!inode) { printk("nfs_file_write: inode = NULL\n"); return -EINVAL; } 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; pos = file->f_pos; if (file->f_flags & O_APPEND) pos = inode->i_size; wsize = NFS_SERVER(inode)->wsize; result = 0; written = 0; while (written < count) { int hunk = count - written; if (hunk >= wsize) hunk = wsize; result = nfs_proc_write(inode, pos, hunk, buf, &fattr); if (result < 0) break; pos += hunk; buf += hunk; written += hunk; if (hunk < wsize) break; } if (!written) return result; file->f_pos = pos; if (pos > inode->i_size) inode->i_size = pos; /* Avoid possible Solaris 2.5 nfsd bug */ if (inode->i_ino == fattr.fileid) nfs_refresh_inode(inode, &fattr); return written; } |