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authorBorislav Petkov <petkovbb@googlemail.com>2008-04-27 09:38:25 -0400
committerBartlomiej Zolnierkiewicz <bzolnier@gmail.com>2008-04-27 09:38:25 -0400
commit5e69bd959d1086f87a603b4ddc6bdb0a130ec7db (patch)
tree557a1e62e25da255ed7ce61cbe6118ed653e9df0 /drivers/ide/ide-tape.c
parentddfe7a776360f7067e06eee9d8b1ae4d957e6ddf (diff)
ide-tape: remove pipeline-specific code from idetape_add_chrdev_read_request()
In order to do away with queueing read requests on the pipeline, several things have to be done: 1. Do not allocate additional pipeline stages in idetape_init_read() until (tape->nr_stages < max_stages) and do only read operation preparations. As a collateral result, idetape_add_stage_tail() becomes unused so remove it. 2. Queue the read request's buffer directly thru idetape_queue_rw_tail(). 3. Remove now unused idetape_kmalloc_stage() and idetape_switch_buffers(). [bart: simplify the original patch] Signed-off-by: Borislav Petkov <petkovbb@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Diffstat (limited to 'drivers/ide/ide-tape.c')
-rw-r--r--drivers/ide/ide-tape.c96
1 files changed, 5 insertions, 91 deletions
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index e785145abb47..e176b5c1b208 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -1586,15 +1586,6 @@ abort:
1586 return NULL; 1586 return NULL;
1587} 1587}
1588 1588
1589static idetape_stage_t *idetape_kmalloc_stage(idetape_tape_t *tape)
1590{
1591 debug_log(DBG_PROCS, "Enter %s\n", __func__);
1592
1593 if (tape->nr_stages >= tape->max_stages)
1594 return NULL;
1595 return __idetape_kmalloc_stage(tape, 0, 0);
1596}
1597
1598static int idetape_copy_stage_from_user(idetape_tape_t *tape, 1589static int idetape_copy_stage_from_user(idetape_tape_t *tape,
1599 idetape_stage_t *stage, const char __user *buf, int n) 1590 idetape_stage_t *stage, const char __user *buf, int n)
1600{ 1591{
@@ -1672,39 +1663,6 @@ static void idetape_init_merge_stage(idetape_tape_t *tape)
1672 } 1663 }
1673} 1664}
1674 1665
1675static void idetape_switch_buffers(idetape_tape_t *tape, idetape_stage_t *stage)
1676{
1677 struct idetape_bh *tmp;
1678
1679 tmp = stage->bh;
1680 stage->bh = tape->merge_stage->bh;
1681 tape->merge_stage->bh = tmp;
1682 idetape_init_merge_stage(tape);
1683}
1684
1685/* Add a new stage at the end of the pipeline. */
1686static void idetape_add_stage_tail(ide_drive_t *drive, idetape_stage_t *stage)
1687{
1688 idetape_tape_t *tape = drive->driver_data;
1689 unsigned long flags;
1690
1691 debug_log(DBG_PROCS, "Enter %s\n", __func__);
1692
1693 spin_lock_irqsave(&tape->lock, flags);
1694 stage->next = NULL;
1695 if (tape->last_stage != NULL)
1696 tape->last_stage->next = stage;
1697 else
1698 tape->first_stage = stage;
1699 tape->next_stage = stage;
1700 tape->last_stage = stage;
1701 if (tape->next_stage == NULL)
1702 tape->next_stage = tape->last_stage;
1703 tape->nr_stages++;
1704 tape->nr_pending_stages++;
1705 spin_unlock_irqrestore(&tape->lock, flags);
1706}
1707
1708/* Install a completion in a pending request and sleep until it is serviced. The 1666/* Install a completion in a pending request and sleep until it is serviced. The
1709 * caller should ensure that the request will not be serviced before we install 1667 * caller should ensure that the request will not be serviced before we install
1710 * the completion (usually by disabling interrupts). 1668 * the completion (usually by disabling interrupts).
@@ -2228,10 +2186,7 @@ static void idetape_empty_write_pipeline(ide_drive_t *drive)
2228static int idetape_init_read(ide_drive_t *drive, int max_stages) 2186static int idetape_init_read(ide_drive_t *drive, int max_stages)
2229{ 2187{
2230 idetape_tape_t *tape = drive->driver_data; 2188 idetape_tape_t *tape = drive->driver_data;
2231 idetape_stage_t *new_stage;
2232 struct request rq;
2233 int bytes_read; 2189 int bytes_read;
2234 u16 blocks = *(u16 *)&tape->caps[12];
2235 2190
2236 /* Initialize read operation */ 2191 /* Initialize read operation */
2237 if (tape->chrdev_dir != IDETAPE_DIR_READ) { 2192 if (tape->chrdev_dir != IDETAPE_DIR_READ) {
@@ -2267,21 +2222,7 @@ static int idetape_init_read(ide_drive_t *drive, int max_stages)
2267 } 2222 }
2268 } 2223 }
2269 } 2224 }
2270 idetape_init_rq(&rq, REQ_IDETAPE_READ); 2225
2271 rq.sector = tape->first_frame;
2272 rq.nr_sectors = blocks;
2273 rq.current_nr_sectors = blocks;
2274 if (!test_bit(IDETAPE_FLAG_PIPELINE_ERR, &tape->flags) &&
2275 tape->nr_stages < max_stages) {
2276 new_stage = idetape_kmalloc_stage(tape);
2277 while (new_stage != NULL) {
2278 new_stage->rq = rq;
2279 idetape_add_stage_tail(drive, new_stage);
2280 if (tape->nr_stages >= max_stages)
2281 break;
2282 new_stage = idetape_kmalloc_stage(tape);
2283 }
2284 }
2285 if (!test_bit(IDETAPE_FLAG_PIPELINE_ACTIVE, &tape->flags)) { 2226 if (!test_bit(IDETAPE_FLAG_PIPELINE_ACTIVE, &tape->flags)) {
2286 if (tape->nr_pending_stages >= 3 * max_stages / 4) { 2227 if (tape->nr_pending_stages >= 3 * max_stages / 4) {
2287 tape->measure_insert_time = 1; 2228 tape->measure_insert_time = 1;
@@ -2301,9 +2242,6 @@ static int idetape_init_read(ide_drive_t *drive, int max_stages)
2301static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks) 2242static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks)
2302{ 2243{
2303 idetape_tape_t *tape = drive->driver_data; 2244 idetape_tape_t *tape = drive->driver_data;
2304 unsigned long flags;
2305 struct request *rq_ptr;
2306 int bytes_read;
2307 2245
2308 debug_log(DBG_PROCS, "Enter %s, %d blocks\n", __func__, blocks); 2246 debug_log(DBG_PROCS, "Enter %s, %d blocks\n", __func__, blocks);
2309 2247
@@ -2311,37 +2249,13 @@ static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks)
2311 if (test_bit(IDETAPE_FLAG_FILEMARK, &tape->flags)) 2249 if (test_bit(IDETAPE_FLAG_FILEMARK, &tape->flags))
2312 return 0; 2250 return 0;
2313 2251
2314 /* Wait for the next block to reach the head of the pipeline. */
2315 idetape_init_read(drive, tape->max_stages); 2252 idetape_init_read(drive, tape->max_stages);
2316 if (tape->first_stage == NULL) {
2317 if (test_bit(IDETAPE_FLAG_PIPELINE_ERR, &tape->flags))
2318 return 0;
2319 return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks,
2320 tape->merge_stage->bh);
2321 }
2322 idetape_wait_first_stage(drive);
2323 rq_ptr = &tape->first_stage->rq;
2324 bytes_read = tape->blk_size * (rq_ptr->nr_sectors -
2325 rq_ptr->current_nr_sectors);
2326 rq_ptr->nr_sectors = 0;
2327 rq_ptr->current_nr_sectors = 0;
2328 2253
2329 if (rq_ptr->errors == IDETAPE_ERROR_EOD) 2254 if (test_bit(IDETAPE_FLAG_PIPELINE_ERR, &tape->flags))
2330 return 0; 2255 return 0;
2331 else { 2256
2332 idetape_switch_buffers(tape, tape->first_stage); 2257 return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks,
2333 if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK) 2258 tape->merge_stage->bh);
2334 set_bit(IDETAPE_FLAG_FILEMARK, &tape->flags);
2335 spin_lock_irqsave(&tape->lock, flags);
2336 idetape_remove_stage_head(drive);
2337 spin_unlock_irqrestore(&tape->lock, flags);
2338 }
2339 if (bytes_read > blocks * tape->blk_size) {
2340 printk(KERN_ERR "ide-tape: bug: trying to return more bytes"
2341 " than requested\n");
2342 bytes_read = blocks * tape->blk_size;
2343 }
2344 return (bytes_read);
2345} 2259}
2346 2260
2347static void idetape_pad_zeros(ide_drive_t *drive, int bcount) 2261static void idetape_pad_zeros(ide_drive_t *drive, int bcount)