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Diffstat (limited to 'arch/um/drivers/ubd_kern.c')
-rw-r--r--arch/um/drivers/ubd_kern.c303
1 files changed, 6 insertions, 297 deletions
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 9a56ff94308d..2a7f6892c55c 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -49,13 +49,12 @@
49#include "irq_user.h" 49#include "irq_user.h"
50#include "irq_kern.h" 50#include "irq_kern.h"
51#include "ubd_user.h" 51#include "ubd_user.h"
52#include "2_5compat.h"
53#include "os.h" 52#include "os.h"
54#include "mem.h" 53#include "mem.h"
55#include "mem_kern.h" 54#include "mem_kern.h"
56#include "cow.h" 55#include "cow.h"
57 56
58enum ubd_req { UBD_READ, UBD_WRITE, UBD_MMAP }; 57enum ubd_req { UBD_READ, UBD_WRITE };
59 58
60struct io_thread_req { 59struct io_thread_req {
61 enum ubd_req op; 60 enum ubd_req op;
@@ -68,8 +67,6 @@ struct io_thread_req {
68 unsigned long sector_mask; 67 unsigned long sector_mask;
69 unsigned long long cow_offset; 68 unsigned long long cow_offset;
70 unsigned long bitmap_words[2]; 69 unsigned long bitmap_words[2];
71 int map_fd;
72 unsigned long long map_offset;
73 int error; 70 int error;
74}; 71};
75 72
@@ -122,10 +119,6 @@ static int ubd_ioctl(struct inode * inode, struct file * file,
122 119
123#define MAX_DEV (8) 120#define MAX_DEV (8)
124 121
125/* Changed in early boot */
126static int ubd_do_mmap = 0;
127#define UBD_MMAP_BLOCK_SIZE PAGE_SIZE
128
129static struct block_device_operations ubd_blops = { 122static struct block_device_operations ubd_blops = {
130 .owner = THIS_MODULE, 123 .owner = THIS_MODULE,
131 .open = ubd_open, 124 .open = ubd_open,
@@ -175,12 +168,6 @@ struct ubd {
175 int no_cow; 168 int no_cow;
176 struct cow cow; 169 struct cow cow;
177 struct platform_device pdev; 170 struct platform_device pdev;
178
179 int map_writes;
180 int map_reads;
181 int nomap_writes;
182 int nomap_reads;
183 int write_maps;
184}; 171};
185 172
186#define DEFAULT_COW { \ 173#define DEFAULT_COW { \
@@ -200,11 +187,6 @@ struct ubd {
200 .openflags = OPEN_FLAGS, \ 187 .openflags = OPEN_FLAGS, \
201 .no_cow = 0, \ 188 .no_cow = 0, \
202 .cow = DEFAULT_COW, \ 189 .cow = DEFAULT_COW, \
203 .map_writes = 0, \
204 .map_reads = 0, \
205 .nomap_writes = 0, \
206 .nomap_reads = 0, \
207 .write_maps = 0, \
208} 190}
209 191
210struct ubd ubd_dev[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD }; 192struct ubd ubd_dev[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD };
@@ -314,13 +296,6 @@ static int ubd_setup_common(char *str, int *index_out)
314 int major; 296 int major;
315 297
316 str++; 298 str++;
317 if(!strcmp(str, "mmap")){
318 CHOOSE_MODE(printk("mmap not supported by the ubd "
319 "driver in tt mode\n"),
320 ubd_do_mmap = 1);
321 return(0);
322 }
323
324 if(!strcmp(str, "sync")){ 299 if(!strcmp(str, "sync")){
325 global_openflags = of_sync(global_openflags); 300 global_openflags = of_sync(global_openflags);
326 return(0); 301 return(0);
@@ -464,9 +439,9 @@ static int udb_setup(char *str)
464__setup("udb", udb_setup); 439__setup("udb", udb_setup);
465__uml_help(udb_setup, 440__uml_help(udb_setup,
466"udb\n" 441"udb\n"
467" This option is here solely to catch ubd -> udb typos, which can be\n\n" 442" This option is here solely to catch ubd -> udb typos, which can be\n"
468" to impossible to catch visually unless you specifically look for\n\n" 443" to impossible to catch visually unless you specifically look for\n"
469" them. The only result of any option starting with 'udb' is an error\n\n" 444" them. The only result of any option starting with 'udb' is an error\n"
470" in the boot output.\n\n" 445" in the boot output.\n\n"
471); 446);
472 447
@@ -524,7 +499,7 @@ static void ubd_handler(void)
524{ 499{
525 struct io_thread_req req; 500 struct io_thread_req req;
526 struct request *rq = elv_next_request(ubd_queue); 501 struct request *rq = elv_next_request(ubd_queue);
527 int n, err; 502 int n;
528 503
529 do_ubd = NULL; 504 do_ubd = NULL;
530 intr_count++; 505 intr_count++;
@@ -538,19 +513,6 @@ static void ubd_handler(void)
538 return; 513 return;
539 } 514 }
540 515
541 if((req.op != UBD_MMAP) &&
542 ((req.offset != ((__u64) (rq->sector)) << 9) ||
543 (req.length != (rq->current_nr_sectors) << 9)))
544 panic("I/O op mismatch");
545
546 if(req.map_fd != -1){
547 err = physmem_subst_mapping(req.buffer, req.map_fd,
548 req.map_offset, 1);
549 if(err)
550 printk("ubd_handler - physmem_subst_mapping failed, "
551 "err = %d\n", -err);
552 }
553
554 ubd_finish(rq, req.error); 516 ubd_finish(rq, req.error);
555 reactivate_fd(thread_fd, UBD_IRQ); 517 reactivate_fd(thread_fd, UBD_IRQ);
556 do_ubd_request(ubd_queue); 518 do_ubd_request(ubd_queue);
@@ -583,14 +545,10 @@ static int ubd_file_size(struct ubd *dev, __u64 *size_out)
583 545
584static void ubd_close(struct ubd *dev) 546static void ubd_close(struct ubd *dev)
585{ 547{
586 if(ubd_do_mmap)
587 physmem_forget_descriptor(dev->fd);
588 os_close_file(dev->fd); 548 os_close_file(dev->fd);
589 if(dev->cow.file == NULL) 549 if(dev->cow.file == NULL)
590 return; 550 return;
591 551
592 if(ubd_do_mmap)
593 physmem_forget_descriptor(dev->cow.fd);
594 os_close_file(dev->cow.fd); 552 os_close_file(dev->cow.fd);
595 vfree(dev->cow.bitmap); 553 vfree(dev->cow.bitmap);
596 dev->cow.bitmap = NULL; 554 dev->cow.bitmap = NULL;
@@ -1010,94 +968,13 @@ static void cowify_req(struct io_thread_req *req, unsigned long *bitmap,
1010 req->bitmap_words, bitmap_len); 968 req->bitmap_words, bitmap_len);
1011} 969}
1012 970
1013static int mmap_fd(struct request *req, struct ubd *dev, __u64 offset)
1014{
1015 __u64 sector;
1016 unsigned char *bitmap;
1017 int bit, i;
1018
1019 /* mmap must have been requested on the command line */
1020 if(!ubd_do_mmap)
1021 return(-1);
1022
1023 /* The buffer must be page aligned */
1024 if(((unsigned long) req->buffer % UBD_MMAP_BLOCK_SIZE) != 0)
1025 return(-1);
1026
1027 /* The request must be a page long */
1028 if((req->current_nr_sectors << 9) != PAGE_SIZE)
1029 return(-1);
1030
1031 if(dev->cow.file == NULL)
1032 return(dev->fd);
1033
1034 sector = offset >> 9;
1035 bitmap = (unsigned char *) dev->cow.bitmap;
1036 bit = ubd_test_bit(sector, bitmap);
1037
1038 for(i = 1; i < req->current_nr_sectors; i++){
1039 if(ubd_test_bit(sector + i, bitmap) != bit)
1040 return(-1);
1041 }
1042
1043 if(bit || (rq_data_dir(req) == WRITE))
1044 offset += dev->cow.data_offset;
1045
1046 /* The data on disk must be page aligned */
1047 if((offset % UBD_MMAP_BLOCK_SIZE) != 0)
1048 return(-1);
1049
1050 return(bit ? dev->fd : dev->cow.fd);
1051}
1052
1053static int prepare_mmap_request(struct ubd *dev, int fd, __u64 offset,
1054 struct request *req,
1055 struct io_thread_req *io_req)
1056{
1057 int err;
1058
1059 if(rq_data_dir(req) == WRITE){
1060 /* Writes are almost no-ops since the new data is already in the
1061 * host page cache
1062 */
1063 dev->map_writes++;
1064 if(dev->cow.file != NULL)
1065 cowify_bitmap(io_req->offset, io_req->length,
1066 &io_req->sector_mask, &io_req->cow_offset,
1067 dev->cow.bitmap, dev->cow.bitmap_offset,
1068 io_req->bitmap_words,
1069 dev->cow.bitmap_len);
1070 }
1071 else {
1072 int w;
1073
1074 if((dev->cow.file != NULL) && (fd == dev->cow.fd))
1075 w = 0;
1076 else w = dev->openflags.w;
1077
1078 if((dev->cow.file != NULL) && (fd == dev->fd))
1079 offset += dev->cow.data_offset;
1080
1081 err = physmem_subst_mapping(req->buffer, fd, offset, w);
1082 if(err){
1083 printk("physmem_subst_mapping failed, err = %d\n",
1084 -err);
1085 return(1);
1086 }
1087 dev->map_reads++;
1088 }
1089 io_req->op = UBD_MMAP;
1090 io_req->buffer = req->buffer;
1091 return(0);
1092}
1093
1094/* Called with ubd_io_lock held */ 971/* Called with ubd_io_lock held */
1095static int prepare_request(struct request *req, struct io_thread_req *io_req) 972static int prepare_request(struct request *req, struct io_thread_req *io_req)
1096{ 973{
1097 struct gendisk *disk = req->rq_disk; 974 struct gendisk *disk = req->rq_disk;
1098 struct ubd *dev = disk->private_data; 975 struct ubd *dev = disk->private_data;
1099 __u64 offset; 976 __u64 offset;
1100 int len, fd; 977 int len;
1101 978
1102 if(req->rq_status == RQ_INACTIVE) return(1); 979 if(req->rq_status == RQ_INACTIVE) return(1);
1103 980
@@ -1114,34 +991,12 @@ static int prepare_request(struct request *req, struct io_thread_req *io_req)
1114 991
1115 io_req->fds[0] = (dev->cow.file != NULL) ? dev->cow.fd : dev->fd; 992 io_req->fds[0] = (dev->cow.file != NULL) ? dev->cow.fd : dev->fd;
1116 io_req->fds[1] = dev->fd; 993 io_req->fds[1] = dev->fd;
1117 io_req->map_fd = -1;
1118 io_req->cow_offset = -1; 994 io_req->cow_offset = -1;
1119 io_req->offset = offset; 995 io_req->offset = offset;
1120 io_req->length = len; 996 io_req->length = len;
1121 io_req->error = 0; 997 io_req->error = 0;
1122 io_req->sector_mask = 0; 998 io_req->sector_mask = 0;
1123 999
1124 fd = mmap_fd(req, dev, io_req->offset);
1125 if(fd > 0){
1126 /* If mmapping is otherwise OK, but the first access to the
1127 * page is a write, then it's not mapped in yet. So we have
1128 * to write the data to disk first, then we can map the disk
1129 * page in and continue normally from there.
1130 */
1131 if((rq_data_dir(req) == WRITE) && !is_remapped(req->buffer)){
1132 io_req->map_fd = dev->fd;
1133 io_req->map_offset = io_req->offset +
1134 dev->cow.data_offset;
1135 dev->write_maps++;
1136 }
1137 else return(prepare_mmap_request(dev, fd, io_req->offset, req,
1138 io_req));
1139 }
1140
1141 if(rq_data_dir(req) == READ)
1142 dev->nomap_reads++;
1143 else dev->nomap_writes++;
1144
1145 io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE; 1000 io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE;
1146 io_req->offsets[0] = 0; 1001 io_req->offsets[0] = 0;
1147 io_req->offsets[1] = dev->cow.data_offset; 1002 io_req->offsets[1] = dev->cow.data_offset;
@@ -1229,143 +1084,6 @@ static int ubd_ioctl(struct inode * inode, struct file * file,
1229 return(-EINVAL); 1084 return(-EINVAL);
1230} 1085}
1231 1086
1232static int ubd_check_remapped(int fd, unsigned long address, int is_write,
1233 __u64 offset)
1234{
1235 __u64 bitmap_offset;
1236 unsigned long new_bitmap[2];
1237 int i, err, n;
1238
1239 /* If it's not a write access, we can't do anything about it */
1240 if(!is_write)
1241 return(0);
1242
1243 /* We have a write */
1244 for(i = 0; i < sizeof(ubd_dev) / sizeof(ubd_dev[0]); i++){
1245 struct ubd *dev = &ubd_dev[i];
1246
1247 if((dev->fd != fd) && (dev->cow.fd != fd))
1248 continue;
1249
1250 /* It's a write to a ubd device */
1251
1252 /* This should be impossible now */
1253 if(!dev->openflags.w){
1254 /* It's a write access on a read-only device - probably
1255 * shouldn't happen. If the kernel is trying to change
1256 * something with no intention of writing it back out,
1257 * then this message will clue us in that this needs
1258 * fixing
1259 */
1260 printk("Write access to mapped page from readonly ubd "
1261 "device %d\n", i);
1262 return(0);
1263 }
1264
1265 /* It's a write to a writeable ubd device - it must be COWed
1266 * because, otherwise, the page would have been mapped in
1267 * writeable
1268 */
1269
1270 if(!dev->cow.file)
1271 panic("Write fault on writeable non-COW ubd device %d",
1272 i);
1273
1274 /* It should also be an access to the backing file since the
1275 * COW pages should be mapped in read-write
1276 */
1277
1278 if(fd == dev->fd)
1279 panic("Write fault on a backing page of ubd "
1280 "device %d\n", i);
1281
1282 /* So, we do the write, copying the backing data to the COW
1283 * file...
1284 */
1285
1286 err = os_seek_file(dev->fd, offset + dev->cow.data_offset);
1287 if(err < 0)
1288 panic("Couldn't seek to %lld in COW file of ubd "
1289 "device %d, err = %d",
1290 offset + dev->cow.data_offset, i, -err);
1291
1292 n = os_write_file(dev->fd, (void *) address, PAGE_SIZE);
1293 if(n != PAGE_SIZE)
1294 panic("Couldn't copy data to COW file of ubd "
1295 "device %d, err = %d", i, -n);
1296
1297 /* ... updating the COW bitmap... */
1298
1299 cowify_bitmap(offset, PAGE_SIZE, NULL, &bitmap_offset,
1300 dev->cow.bitmap, dev->cow.bitmap_offset,
1301 new_bitmap, dev->cow.bitmap_len);
1302
1303 err = os_seek_file(dev->fd, bitmap_offset);
1304 if(err < 0)
1305 panic("Couldn't seek to %lld in COW file of ubd "
1306 "device %d, err = %d", bitmap_offset, i, -err);
1307
1308 n = os_write_file(dev->fd, new_bitmap, sizeof(new_bitmap));
1309 if(n != sizeof(new_bitmap))
1310 panic("Couldn't update bitmap of ubd device %d, "
1311 "err = %d", i, -n);
1312
1313 /* Maybe we can map the COW page in, and maybe we can't. If
1314 * it is a pre-V3 COW file, we can't, since the alignment will
1315 * be wrong. If it is a V3 or later COW file which has been
1316 * moved to a system with a larger page size, then maybe we
1317 * can't, depending on the exact location of the page.
1318 */
1319
1320 offset += dev->cow.data_offset;
1321
1322 /* Remove the remapping, putting the original anonymous page
1323 * back. If the COW file can be mapped in, that is done.
1324 * Otherwise, the COW page is read in.
1325 */
1326
1327 if(!physmem_remove_mapping((void *) address))
1328 panic("Address 0x%lx not remapped by ubd device %d",
1329 address, i);
1330 if((offset % UBD_MMAP_BLOCK_SIZE) == 0)
1331 physmem_subst_mapping((void *) address, dev->fd,
1332 offset, 1);
1333 else {
1334 err = os_seek_file(dev->fd, offset);
1335 if(err < 0)
1336 panic("Couldn't seek to %lld in COW file of "
1337 "ubd device %d, err = %d", offset, i,
1338 -err);
1339
1340 n = os_read_file(dev->fd, (void *) address, PAGE_SIZE);
1341 if(n != PAGE_SIZE)
1342 panic("Failed to read page from offset %llx of "
1343 "COW file of ubd device %d, err = %d",
1344 offset, i, -n);
1345 }
1346
1347 return(1);
1348 }
1349
1350 /* It's not a write on a ubd device */
1351 return(0);
1352}
1353
1354static struct remapper ubd_remapper = {
1355 .list = LIST_HEAD_INIT(ubd_remapper.list),
1356 .proc = ubd_check_remapped,
1357};
1358
1359static int ubd_remapper_setup(void)
1360{
1361 if(ubd_do_mmap)
1362 register_remapper(&ubd_remapper);
1363
1364 return(0);
1365}
1366
1367__initcall(ubd_remapper_setup);
1368
1369static int same_backing_files(char *from_cmdline, char *from_cow, char *cow) 1087static int same_backing_files(char *from_cmdline, char *from_cow, char *cow)
1370{ 1088{
1371 struct uml_stat buf1, buf2; 1089 struct uml_stat buf1, buf2;
@@ -1568,15 +1286,6 @@ void do_io(struct io_thread_req *req)
1568 int err; 1286 int err;
1569 __u64 off; 1287 __u64 off;
1570 1288
1571 if(req->op == UBD_MMAP){
1572 /* Touch the page to force the host to do any necessary IO to
1573 * get it into memory
1574 */
1575 n = *((volatile int *) req->buffer);
1576 req->error = update_bitmap(req);
1577 return;
1578 }
1579
1580 nsectors = req->length / req->sectorsize; 1289 nsectors = req->length / req->sectorsize;
1581 start = 0; 1290 start = 0;
1582 do { 1291 do {