3 files changed, 32 insertions, 29 deletions

diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index db6818fdf15d..8b1331677407 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -433,8 +433,8 @@ config CDROM_PKTCDVD_BUFFERS
           This controls the maximum number of active concurrent packets. More
           concurrent packets can increase write performance, but also require
           more memory. Each concurrent packet will require approximately 64Kb
-          of non-swappable kernel memory, memory which will be allocated at
-          pktsetup time.
+          of non-swappable kernel memory, memory which will be allocated when
+          a disc is opened for writing.
 
 config CDROM_PKTCDVD_WCACHE
         bool "Enable write caching (EXPERIMENTAL)"
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index cd16813effc5..4e7dbcc425ff 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -129,7 +129,7 @@ static struct bio *pkt_bio_alloc(int nr_iovecs)
 /*
  * Allocate a packet_data struct
  */
-static struct packet_data *pkt_alloc_packet_data(void)
+static struct packet_data *pkt_alloc_packet_data(int frames)
 {
         int i;
         struct packet_data *pkt;
@@ -138,11 +138,12 @@ static struct packet_data *pkt_alloc_packet_data(void)
         if (!pkt)
                 goto no_pkt;
 
-        pkt->w_bio = pkt_bio_alloc(PACKET_MAX_SIZE);
+        pkt->frames = frames;
+        pkt->w_bio = pkt_bio_alloc(frames);
         if (!pkt->w_bio)
                 goto no_bio;
 
-        for (i = 0; i < PAGES_PER_PACKET; i++) {
+        for (i = 0; i < frames / FRAMES_PER_PAGE; i++) {
                 pkt->pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
                 if (!pkt->pages[i])
                         goto no_page;
@@ -150,7 +151,7 @@ static struct packet_data *pkt_alloc_packet_data(void)
 
         spin_lock_init(&pkt->lock);
 
-        for (i = 0; i < PACKET_MAX_SIZE; i++) {
+        for (i = 0; i < frames; i++) {
                 struct bio *bio = pkt_bio_alloc(1);
                 if (!bio)
                         goto no_rd_bio;
@@ -160,14 +161,14 @@ static struct packet_data *pkt_alloc_packet_data(void)
         return pkt;
 
 no_rd_bio:
-        for (i = 0; i < PACKET_MAX_SIZE; i++) {
+        for (i = 0; i < frames; i++) {
                 struct bio *bio = pkt->r_bios[i];
                 if (bio)
                         bio_put(bio);
         }
 
 no_page:
-        for (i = 0; i < PAGES_PER_PACKET; i++)
+        for (i = 0; i < frames / FRAMES_PER_PAGE; i++)
                 if (pkt->pages[i])
                         __free_page(pkt->pages[i]);
         bio_put(pkt->w_bio);
@@ -184,12 +185,12 @@ static void pkt_free_packet_data(struct packet_data *pkt)
 {
         int i;
 
-        for (i = 0; i < PACKET_MAX_SIZE; i++) {
+        for (i = 0; i < pkt->frames; i++) {
                 struct bio *bio = pkt->r_bios[i];
                 if (bio)
                         bio_put(bio);
         }
-        for (i = 0; i < PAGES_PER_PACKET; i++)
+        for (i = 0; i < pkt->frames / FRAMES_PER_PAGE; i++)
                 __free_page(pkt->pages[i]);
         bio_put(pkt->w_bio);
         kfree(pkt);
@@ -204,17 +205,17 @@ static void pkt_shrink_pktlist(struct pktcdvd_device *pd)
         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_free_list, list) {
                 pkt_free_packet_data(pkt);
         }
+        INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
 }
 
 static int pkt_grow_pktlist(struct pktcdvd_device *pd, int nr_packets)
 {
         struct packet_data *pkt;
 
-        INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
-        INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
-        spin_lock_init(&pd->cdrw.active_list_lock);
+        BUG_ON(!list_empty(&pd->cdrw.pkt_free_list));
+
         while (nr_packets > 0) {
-                pkt = pkt_alloc_packet_data();
+                pkt = pkt_alloc_packet_data(pd->settings.size >> 2);
                 if (!pkt) {
                         pkt_shrink_pktlist(pd);
                         return 0;
@@ -949,7 +950,7 @@ try_next_bio:
 
         pd->current_sector = zone + pd->settings.size;
         pkt->sector = zone;
-        pkt->frames = pd->settings.size >> 2;
+        BUG_ON(pkt->frames != pd->settings.size >> 2);
         pkt->write_size = 0;
 
         /*
@@ -1985,8 +1986,14 @@ static int pkt_open_dev(struct pktcdvd_device *pd, int write)
         if ((ret = pkt_set_segment_merging(pd, q)))
                 goto out_unclaim;
 
-        if (write)
+        if (write) {
+                if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
+                        printk("pktcdvd: not enough memory for buffers\n");
+                        ret = -ENOMEM;
+                        goto out_unclaim;
+                }
                 printk("pktcdvd: %lukB available on disc\n", lba << 1);
+        }
 
         return 0;
 
@@ -2012,6 +2019,8 @@ static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
         bd_release(pd->bdev);
         blkdev_put(pd->bdev);
+
+        pkt_shrink_pktlist(pd);
 }
 
 static struct pktcdvd_device *pkt_find_dev_from_minor(int dev_minor)
@@ -2377,12 +2386,6 @@ static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
         /* This is safe, since we have a reference from open(). */
         __module_get(THIS_MODULE);
 
-        if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
-                printk("pktcdvd: not enough memory for buffers\n");
-                ret = -ENOMEM;
-                goto out_mem;
-        }
-
         pd->bdev = bdev;
         set_blocksize(bdev, CD_FRAMESIZE);
 
@@ -2393,7 +2396,7 @@ static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
         if (IS_ERR(pd->cdrw.thread)) {
                 printk("pktcdvd: can't start kernel thread\n");
                 ret = -ENOMEM;
-                goto out_thread;
+                goto out_mem;
         }
 
         proc = create_proc_entry(pd->name, 0, pkt_proc);
@@ -2404,8 +2407,6 @@ static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
         DPRINTK("pktcdvd: writer %s mapped to %s\n", pd->name, bdevname(bdev, b));
         return 0;
 
-out_thread:
-        pkt_shrink_pktlist(pd);
 out_mem:
         blkdev_put(bdev);
         /* This is safe: open() is still holding a reference. */
@@ -2501,6 +2502,10 @@ static int pkt_setup_dev(struct pkt_ctrl_command *ctrl_cmd)
                 goto out_mem;
         pd->disk = disk;
 
+        INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
+        INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
+        spin_lock_init(&pd->cdrw.active_list_lock);
+
         spin_lock_init(&pd->lock);
         spin_lock_init(&pd->iosched.lock);
         sprintf(pd->name, "pktcdvd%d", idx);
@@ -2565,8 +2570,6 @@ static int pkt_remove_dev(struct pkt_ctrl_command *ctrl_cmd)
 
         blkdev_put(pd->bdev);
 
-        pkt_shrink_pktlist(pd);
-
         remove_proc_entry(pd->name, pkt_proc);
         DPRINTK("pktcdvd: writer %s unmapped\n", pd->name);
 
diff --git a/include/linux/pktcdvd.h b/include/linux/pktcdvd.h
index d1c9c4a86e52..1623da88d6fe 100644
--- a/include/linux/pktcdvd.h
+++ b/include/linux/pktcdvd.h
@@ -170,7 +170,7 @@ struct packet_iosched
 #error "PAGE_SIZE must be a multiple of CD_FRAMESIZE"
 #endif
 #define PACKET_MAX_SIZE         32
-#define PAGES_PER_PACKET        (PACKET_MAX_SIZE * CD_FRAMESIZE / PAGE_SIZE)
+#define FRAMES_PER_PAGE         (PAGE_SIZE / CD_FRAMESIZE)
 #define PACKET_MAX_SECTORS      (PACKET_MAX_SIZE * CD_FRAMESIZE >> 9)
 
 enum packet_data_state {
@@ -219,7 +219,7 @@ struct packet_data
         atomic_t                io_errors;      /* Number of read/write errors during IO */
 
         struct bio              *r_bios[PACKET_MAX_SIZE]; /* bios to use during data gathering */
-        struct page             *pages[PAGES_PER_PACKET];
+        struct page             *pages[PACKET_MAX_SIZE / FRAMES_PER_PAGE];
 
         int                     cache_valid;    /* If non-zero, the data for the zone defined */
                                                 /* by the sector variable is completely cached */