aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/block/loop.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/block/loop.c')
-rw-r--r--drivers/block/loop.c47
1 files changed, 31 insertions, 16 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 3d806820280e..68b205a9338f 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -161,17 +161,19 @@ static struct loop_func_table *xfer_funcs[MAX_LO_CRYPT] = {
161 &xor_funcs 161 &xor_funcs
162}; 162};
163 163
164static loff_t get_loop_size(struct loop_device *lo, struct file *file) 164static loff_t get_size(loff_t offset, loff_t sizelimit, struct file *file)
165{ 165{
166 loff_t size, offset, loopsize; 166 loff_t size, loopsize;
167 167
168 /* Compute loopsize in bytes */ 168 /* Compute loopsize in bytes */
169 size = i_size_read(file->f_mapping->host); 169 size = i_size_read(file->f_mapping->host);
170 offset = lo->lo_offset;
171 loopsize = size - offset; 170 loopsize = size - offset;
172 if (lo->lo_sizelimit > 0 && lo->lo_sizelimit < loopsize) 171 /* offset is beyond i_size, wierd but possible */
173 loopsize = lo->lo_sizelimit; 172 if (loopsize < 0)
173 return 0;
174 174
175 if (sizelimit > 0 && sizelimit < loopsize)
176 loopsize = sizelimit;
175 /* 177 /*
176 * Unfortunately, if we want to do I/O on the device, 178 * Unfortunately, if we want to do I/O on the device,
177 * the number of 512-byte sectors has to fit into a sector_t. 179 * the number of 512-byte sectors has to fit into a sector_t.
@@ -179,17 +181,25 @@ static loff_t get_loop_size(struct loop_device *lo, struct file *file)
179 return loopsize >> 9; 181 return loopsize >> 9;
180} 182}
181 183
184static loff_t get_loop_size(struct loop_device *lo, struct file *file)
185{
186 return get_size(lo->lo_offset, lo->lo_sizelimit, file);
187}
188
182static int 189static int
183figure_loop_size(struct loop_device *lo) 190figure_loop_size(struct loop_device *lo, loff_t offset, loff_t sizelimit)
184{ 191{
185 loff_t size = get_loop_size(lo, lo->lo_backing_file); 192 loff_t size = get_size(offset, sizelimit, lo->lo_backing_file);
186 sector_t x = (sector_t)size; 193 sector_t x = (sector_t)size;
187 194
188 if (unlikely((loff_t)x != size)) 195 if (unlikely((loff_t)x != size))
189 return -EFBIG; 196 return -EFBIG;
190 197 if (lo->lo_offset != offset)
198 lo->lo_offset = offset;
199 if (lo->lo_sizelimit != sizelimit)
200 lo->lo_sizelimit = sizelimit;
191 set_capacity(lo->lo_disk, x); 201 set_capacity(lo->lo_disk, x);
192 return 0; 202 return 0;
193} 203}
194 204
195static inline int 205static inline int
@@ -372,7 +382,8 @@ do_lo_receive(struct loop_device *lo,
372 382
373 if (retval < 0) 383 if (retval < 0)
374 return retval; 384 return retval;
375 385 if (retval != bvec->bv_len)
386 return -EIO;
376 return 0; 387 return 0;
377} 388}
378 389
@@ -1058,9 +1069,7 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
1058 1069
1059 if (lo->lo_offset != info->lo_offset || 1070 if (lo->lo_offset != info->lo_offset ||
1060 lo->lo_sizelimit != info->lo_sizelimit) { 1071 lo->lo_sizelimit != info->lo_sizelimit) {
1061 lo->lo_offset = info->lo_offset; 1072 if (figure_loop_size(lo, info->lo_offset, info->lo_sizelimit))
1062 lo->lo_sizelimit = info->lo_sizelimit;
1063 if (figure_loop_size(lo))
1064 return -EFBIG; 1073 return -EFBIG;
1065 } 1074 }
1066 loop_config_discard(lo); 1075 loop_config_discard(lo);
@@ -1246,7 +1255,7 @@ static int loop_set_capacity(struct loop_device *lo, struct block_device *bdev)
1246 err = -ENXIO; 1255 err = -ENXIO;
1247 if (unlikely(lo->lo_state != Lo_bound)) 1256 if (unlikely(lo->lo_state != Lo_bound))
1248 goto out; 1257 goto out;
1249 err = figure_loop_size(lo); 1258 err = figure_loop_size(lo, lo->lo_offset, lo->lo_sizelimit);
1250 if (unlikely(err)) 1259 if (unlikely(err))
1251 goto out; 1260 goto out;
1252 sec = get_capacity(lo->lo_disk); 1261 sec = get_capacity(lo->lo_disk);
@@ -1284,13 +1293,19 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
1284 goto out_unlocked; 1293 goto out_unlocked;
1285 break; 1294 break;
1286 case LOOP_SET_STATUS: 1295 case LOOP_SET_STATUS:
1287 err = loop_set_status_old(lo, (struct loop_info __user *) arg); 1296 err = -EPERM;
1297 if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN))
1298 err = loop_set_status_old(lo,
1299 (struct loop_info __user *)arg);
1288 break; 1300 break;
1289 case LOOP_GET_STATUS: 1301 case LOOP_GET_STATUS:
1290 err = loop_get_status_old(lo, (struct loop_info __user *) arg); 1302 err = loop_get_status_old(lo, (struct loop_info __user *) arg);
1291 break; 1303 break;
1292 case LOOP_SET_STATUS64: 1304 case LOOP_SET_STATUS64:
1293 err = loop_set_status64(lo, (struct loop_info64 __user *) arg); 1305 err = -EPERM;
1306 if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN))
1307 err = loop_set_status64(lo,
1308 (struct loop_info64 __user *) arg);
1294 break; 1309 break;
1295 case LOOP_GET_STATUS64: 1310 case LOOP_GET_STATUS64:
1296 err = loop_get_status64(lo, (struct loop_info64 __user *) arg); 1311 err = loop_get_status64(lo, (struct loop_info64 __user *) arg);