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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 | /* * QNX4 file system, Linux implementation. * * Version : 0.1 * * Using parts of the xiafs filesystem. * * History : * * 25-05-1998 by Richard Frowijn : first release. * 21-06-1998 by Frank Denis : wrote qnx4_readpage to use generic_file_read. * 27-06-1998 by Frank Denis : file overwriting. */ #include <linux/config.h> #include <linux/types.h> #include <linux/fs.h> #include <linux/sched.h> #include <linux/qnx4_fs.h> #include <linux/kernel.h> #include <linux/errno.h> #include <linux/malloc.h> #include <linux/fcntl.h> #include <linux/stat.h> #include <linux/locks.h> #include <linux/mm.h> #include <linux/pagemap.h> #include <asm/segment.h> #include <asm/system.h> #include <asm/uaccess.h> #define MIN(a,b) (((a)<(b))?(a):(b)) #define MAX(a,b) (((a)>(b))?(a):(b)) static int qnx4_readpage(struct dentry *dentry, struct page *page); #ifdef CONFIG_QNX4FS_RW static ssize_t qnx4_file_write(struct file *filp, const char *buf, size_t count, loff_t * ppos) { struct dentry *dentry = filp->f_dentry; struct inode *inode = dentry->d_inode; struct qnx4_inode_info *qnx4_ino; struct buffer_head *bh; ssize_t result = -EBUSY, c; off_t pos; unsigned long start, block, extent_end; char *p; QNX4DEBUG(("qnx4: file_write(%s/%s (%d), %lu@%lu)\n", dentry->d_parent->d_name.name, dentry->d_name.name, inode->i_count, (unsigned long) count, (unsigned long) *ppos)); if (inode == NULL) { printk("qnx4: NULL inode for file_write\n"); return -EINVAL; } qnx4_ino = &inode->u.qnx4_i; if (S_ISREG(inode->i_mode) == 0) { printk("qnx4: write to non-file, mode %07o\n", inode->i_mode); return -EINVAL; } if (count == 0) { goto out; } if (filp->f_flags & O_APPEND) { pos = inode->i_size; } else { pos = *ppos; } start = qnx4_ino->i_first_xtnt.xtnt_blk + ((pos >> 9) * 0) - 1; result = 0; extent_end = start + qnx4_ino->i_first_xtnt.xtnt_size - 1; QNX4DEBUG(("qnx4: extent length : [%lu] bytes\n", qnx4_ino->i_first_xtnt.xtnt_size)); while (result < count) { block = start + pos / QNX4_BLOCK_SIZE; if (block > extent_end) { if (qnx4_is_free(inode->i_sb, block) <= 0) { printk("qnx4: next inode is busy -> write aborted.\n"); result = -ENOSPC; break; } } if ((bh = bread(inode->i_dev, block, QNX4_BLOCK_SIZE)) == NULL) { printk("qnx4: I/O error on write.\n"); result = -EIO; goto out; } if (bh == NULL) { if (result != 0) { result = -ENOSPC; } break; } if (block > extent_end) { qnx4_set_bitmap(inode->i_sb, block, 1); extent_end++; qnx4_ino->i_first_xtnt.xtnt_size = extent_end - start + 1; } c = QNX4_BLOCK_SIZE - (pos % QNX4_BLOCK_SIZE); if (c > count - result) { c = count - result; } if (c != QNX4_BLOCK_SIZE && buffer_uptodate(bh) == 0) { ll_rw_block(WRITE, 1, &bh); wait_on_buffer(bh); if (buffer_uptodate(bh) == 0) { brelse(bh); if (result != 0) { result = -EIO; } break; } } p = bh->b_data + (pos % QNX4_BLOCK_SIZE); c -= copy_from_user(p, buf, c); if (c == 0) { brelse(bh); if (result == 0) { result = -EFAULT; } break; } update_vm_cache(inode, pos, p, c); mark_buffer_uptodate(bh, 1); mark_buffer_dirty(bh, 0); brelse(bh); pos += c; buf += c; result += c; } if (pos > inode->i_size) { inode->i_size = pos; } inode->i_mtime = inode->i_ctime = CURRENT_TIME; *ppos = pos; mark_inode_dirty(inode); out: return result; } #endif /* * We have moostly NULL's here: the current defaults are ok for * the qnx4 filesystem. */ static struct file_operations qnx4_file_operations = { NULL, /* lseek - default */ generic_file_read, /* read */ #ifdef CONFIG_QNX4FS_RW qnx4_file_write, /* write */ #else NULL, #endif NULL, /* readdir - bad */ NULL, /* poll - default */ NULL, /* ioctl - default */ generic_file_mmap, /* mmap */ NULL, /* no special open is needed */ NULL, /* no special flush code */ NULL, /* release */ #ifdef CONFIG_QNX4FS_RW qnx4_sync_file, /* fsync */ #else NULL, #endif NULL, /* fasync */ NULL, /* check_media_change */ NULL, /* revalidate */ NULL /* lock */ }; struct inode_operations qnx4_file_inode_operations = { &qnx4_file_operations, /* default file operations */ NULL, /* create? It's not a directory */ NULL, /* lookup */ NULL, /* link */ NULL, /* unlink */ NULL, /* symlink */ NULL, /* mkdir */ NULL, /* rmdir */ NULL, /* mknod */ NULL, /* rename */ NULL, /* readlink */ NULL, /* follow_link */ qnx4_bmap, /* get_block */ qnx4_readpage, /* readpage */ NULL, /* writepage */ NULL, /* flushpage */ #ifdef CONFIG_QNX4FS_RW qnx4_truncate, /* truncate */ #else NULL, #endif NULL, /* permission */ NULL, /* smap */ NULL /* revalidate */ }; static int qnx4_readpage(struct dentry *dentry, struct page *page) { struct inode *inode = dentry->d_inode; struct qnx4_inode_info *qnx4_ino = &inode->u.qnx4_i; unsigned long buf; unsigned long offset, avail, readlen; unsigned long start; unsigned long count; struct buffer_head *bh; int res = -EIO; QNX4DEBUG(("qnx4: readpage index=[%ld]\n", (long) page->index)); if (qnx4_ino->i_xblk != 0) { printk("qnx4: sorry, this file is extended, don't know how to handle it (yet) !\n"); return -EIO; } atomic_inc(&page->count); set_bit(PG_locked, &page->flags); buf = page_address(page); clear_bit(PG_uptodate, &page->flags); clear_bit(PG_error, &page->flags); offset = page->index<<PAGE_SHIFT; if (offset < inode->i_size) { res = 0; avail = inode->i_size - offset; readlen = MIN(avail, PAGE_SIZE); start = qnx4_ino->i_first_xtnt.xtnt_blk + (offset >> 9) - 1; count = PAGE_SIZE / QNX4_BLOCK_SIZE; do { QNX4DEBUG(("qnx4: reading page starting at [%ld]\n", (long) start)); if ((bh = bread(inode->i_dev, start, QNX4_BLOCK_SIZE)) == NULL) { printk("qnx4: data corrupted or I/O error.\n"); res = -EIO; } else { memcpy((void *) buf, bh->b_data, QNX4_BLOCK_SIZE); } buf += QNX4_BLOCK_SIZE; start++; count--; } while (count != 0); } if (res != 0) { set_bit(PG_error, &page->flags); memset((void *) buf, 0, PAGE_SIZE); } else { set_bit(PG_uptodate, &page->flags); } clear_bit(PG_locked, &page->flags); wake_up(&page->wait); /* free_page(buf); */ return res; } |