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path: root/drivers/block/brd.c
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Diffstat (limited to 'drivers/block/brd.c')
-rw-r--r--drivers/block/brd.c114
1 files changed, 65 insertions, 49 deletions
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index b7f51e4594f..c7d138eca73 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -17,7 +17,7 @@
#include <linux/highmem.h>
#include <linux/mutex.h>
#include <linux/radix-tree.h>
-#include <linux/buffer_head.h> /* invalidate_bh_lrus() */
+#include <linux/fs.h>
#include <linux/slab.h>
#include <asm/uaccess.h>
@@ -35,10 +35,6 @@
*/
struct brd_device {
int brd_number;
- int brd_refcnt;
- loff_t brd_offset;
- loff_t brd_sizelimit;
- unsigned brd_blocksize;
struct request_queue *brd_queue;
struct gendisk *brd_disk;
@@ -121,13 +117,13 @@ static struct page *brd_insert_page(struct brd_device *brd, sector_t sector)
spin_lock(&brd->brd_lock);
idx = sector >> PAGE_SECTORS_SHIFT;
+ page->index = idx;
if (radix_tree_insert(&brd->brd_pages, idx, page)) {
__free_page(page);
page = radix_tree_lookup(&brd->brd_pages, idx);
BUG_ON(!page);
BUG_ON(page->index != idx);
- } else
- page->index = idx;
+ }
spin_unlock(&brd->brd_lock);
radix_tree_preload_end();
@@ -204,11 +200,11 @@ static int copy_to_brd_setup(struct brd_device *brd, sector_t sector, size_t n)
copy = min_t(size_t, n, PAGE_SIZE - offset);
if (!brd_insert_page(brd, sector))
- return -ENOMEM;
+ return -ENOSPC;
if (copy < n) {
sector += copy >> SECTOR_SHIFT;
if (!brd_insert_page(brd, sector))
- return -ENOMEM;
+ return -ENOSPC;
}
return 0;
}
@@ -246,9 +242,9 @@ static void copy_to_brd(struct brd_device *brd, const void *src,
page = brd_lookup_page(brd, sector);
BUG_ON(!page);
- dst = kmap_atomic(page, KM_USER1);
+ dst = kmap_atomic(page);
memcpy(dst + offset, src, copy);
- kunmap_atomic(dst, KM_USER1);
+ kunmap_atomic(dst);
if (copy < n) {
src += copy;
@@ -257,9 +253,9 @@ static void copy_to_brd(struct brd_device *brd, const void *src,
page = brd_lookup_page(brd, sector);
BUG_ON(!page);
- dst = kmap_atomic(page, KM_USER1);
+ dst = kmap_atomic(page);
memcpy(dst, src, copy);
- kunmap_atomic(dst, KM_USER1);
+ kunmap_atomic(dst);
}
}
@@ -277,9 +273,9 @@ static void copy_from_brd(void *dst, struct brd_device *brd,
copy = min_t(size_t, n, PAGE_SIZE - offset);
page = brd_lookup_page(brd, sector);
if (page) {
- src = kmap_atomic(page, KM_USER1);
+ src = kmap_atomic(page);
memcpy(dst, src + offset, copy);
- kunmap_atomic(src, KM_USER1);
+ kunmap_atomic(src);
} else
memset(dst, 0, copy);
@@ -289,9 +285,9 @@ static void copy_from_brd(void *dst, struct brd_device *brd,
copy = n - copy;
page = brd_lookup_page(brd, sector);
if (page) {
- src = kmap_atomic(page, KM_USER1);
+ src = kmap_atomic(page);
memcpy(dst, src, copy);
- kunmap_atomic(src, KM_USER1);
+ kunmap_atomic(src);
} else
memset(dst, 0, copy);
}
@@ -313,7 +309,7 @@ static int brd_do_bvec(struct brd_device *brd, struct page *page,
goto out;
}
- mem = kmap_atomic(page, KM_USER0);
+ mem = kmap_atomic(page);
if (rw == READ) {
copy_from_brd(mem + off, brd, sector, len);
flush_dcache_page(page);
@@ -321,30 +317,29 @@ static int brd_do_bvec(struct brd_device *brd, struct page *page,
flush_dcache_page(page);
copy_to_brd(brd, mem + off, sector, len);
}
- kunmap_atomic(mem, KM_USER0);
+ kunmap_atomic(mem);
out:
return err;
}
-static int brd_make_request(struct request_queue *q, struct bio *bio)
+static void brd_make_request(struct request_queue *q, struct bio *bio)
{
struct block_device *bdev = bio->bi_bdev;
struct brd_device *brd = bdev->bd_disk->private_data;
int rw;
- struct bio_vec *bvec;
+ struct bio_vec bvec;
sector_t sector;
- int i;
+ struct bvec_iter iter;
int err = -EIO;
- sector = bio->bi_sector;
- if (sector + (bio->bi_size >> SECTOR_SHIFT) >
- get_capacity(bdev->bd_disk))
+ sector = bio->bi_iter.bi_sector;
+ if (bio_end_sector(bio) > get_capacity(bdev->bd_disk))
goto out;
if (unlikely(bio->bi_rw & REQ_DISCARD)) {
err = 0;
- discard_from_brd(brd, sector, bio->bi_size);
+ discard_from_brd(brd, sector, bio->bi_iter.bi_size);
goto out;
}
@@ -352,10 +347,10 @@ static int brd_make_request(struct request_queue *q, struct bio *bio)
if (rw == READA)
rw = READ;
- bio_for_each_segment(bvec, bio, i) {
- unsigned int len = bvec->bv_len;
- err = brd_do_bvec(brd, bvec->bv_page, len,
- bvec->bv_offset, rw, sector);
+ bio_for_each_segment(bvec, bio, iter) {
+ unsigned int len = bvec.bv_len;
+ err = brd_do_bvec(brd, bvec.bv_page, len,
+ bvec.bv_offset, rw, sector);
if (err)
break;
sector += len >> SECTOR_SHIFT;
@@ -363,8 +358,15 @@ static int brd_make_request(struct request_queue *q, struct bio *bio)
out:
bio_endio(bio, err);
+}
- return 0;
+static int brd_rw_page(struct block_device *bdev, sector_t sector,
+ struct page *page, int rw)
+{
+ struct brd_device *brd = bdev->bd_disk->private_data;
+ int err = brd_do_bvec(brd, page, PAGE_CACHE_SIZE, 0, rw, sector);
+ page_endio(page, rw & WRITE, err);
+ return err;
}
#ifdef CONFIG_BLK_DEV_XIP
@@ -382,7 +384,7 @@ static int brd_direct_access(struct block_device *bdev, sector_t sector,
return -ERANGE;
page = brd_insert_page(brd, sector);
if (!page)
- return -ENOMEM;
+ return -ENOSPC;
*kaddr = page_address(page);
*pfn = page_to_pfn(page);
@@ -408,14 +410,13 @@ static int brd_ioctl(struct block_device *bdev, fmode_t mode,
error = -EBUSY;
if (bdev->bd_openers <= 1) {
/*
- * Invalidate the cache first, so it isn't written
- * back to the device.
+ * Kill the cache first, so it isn't written back to the
+ * device.
*
* Another thread might instantiate more buffercache here,
* but there is not much we can do to close that race.
*/
- invalidate_bh_lrus();
- truncate_inode_pages(bdev->bd_inode->i_mapping, 0);
+ kill_bdev(bdev);
brd_free_pages(brd);
error = 0;
}
@@ -427,6 +428,7 @@ static int brd_ioctl(struct block_device *bdev, fmode_t mode,
static const struct block_device_operations brd_fops = {
.owner = THIS_MODULE,
+ .rw_page = brd_rw_page,
.ioctl = brd_ioctl,
#ifdef CONFIG_BLK_DEV_XIP
.direct_access = brd_direct_access,
@@ -440,11 +442,11 @@ static int rd_nr;
int rd_size = CONFIG_BLK_DEV_RAM_SIZE;
static int max_part;
static int part_shift;
-module_param(rd_nr, int, 0);
+module_param(rd_nr, int, S_IRUGO);
MODULE_PARM_DESC(rd_nr, "Maximum number of brd devices");
-module_param(rd_size, int, 0);
+module_param(rd_size, int, S_IRUGO);
MODULE_PARM_DESC(rd_size, "Size of each RAM disk in kbytes.");
-module_param(max_part, int, 0);
+module_param(max_part, int, S_IRUGO);
MODULE_PARM_DESC(max_part, "Maximum number of partitions per RAM disk");
MODULE_LICENSE("GPL");
MODULE_ALIAS_BLOCKDEV_MAJOR(RAMDISK_MAJOR);
@@ -552,8 +554,8 @@ static struct kobject *brd_probe(dev_t dev, int *part, void *data)
struct kobject *kobj;
mutex_lock(&brd_devices_mutex);
- brd = brd_init_one(dev & MINORMASK);
- kobj = brd ? get_disk(brd->brd_disk) : ERR_PTR(-ENOMEM);
+ brd = brd_init_one(MINOR(dev) >> part_shift);
+ kobj = brd ? get_disk(brd->brd_disk) : NULL;
mutex_unlock(&brd_devices_mutex);
*part = 0;
@@ -575,25 +577,39 @@ static int __init brd_init(void)
*
* (1) if rd_nr is specified, create that many upfront, and this
* also becomes a hard limit.
- * (2) if rd_nr is not specified, create 1 rd device on module
- * load, user can further extend brd device by create dev node
- * themselves and have kernel automatically instantiate actual
- * device on-demand.
+ * (2) if rd_nr is not specified, create CONFIG_BLK_DEV_RAM_COUNT
+ * (default 16) rd device on module load, user can further
+ * extend brd device by create dev node themselves and have
+ * kernel automatically instantiate actual device on-demand.
*/
part_shift = 0;
- if (max_part > 0)
+ if (max_part > 0) {
part_shift = fls(max_part);
+ /*
+ * Adjust max_part according to part_shift as it is exported
+ * to user space so that user can decide correct minor number
+ * if [s]he want to create more devices.
+ *
+ * Note that -1 is required because partition 0 is reserved
+ * for the whole disk.
+ */
+ max_part = (1UL << part_shift) - 1;
+ }
+
+ if ((1UL << part_shift) > DISK_MAX_PARTS)
+ return -EINVAL;
+
if (rd_nr > 1UL << (MINORBITS - part_shift))
return -EINVAL;
if (rd_nr) {
nr = rd_nr;
- range = rd_nr;
+ range = rd_nr << part_shift;
} else {
nr = CONFIG_BLK_DEV_RAM_COUNT;
- range = 1UL << (MINORBITS - part_shift);
+ range = 1UL << MINORBITS;
}
if (register_blkdev(RAMDISK_MAJOR, "ramdisk"))
@@ -632,7 +648,7 @@ static void __exit brd_exit(void)
unsigned long range;
struct brd_device *brd, *next;
- range = rd_nr ? rd_nr : 1UL << (MINORBITS - part_shift);
+ range = rd_nr ? rd_nr << part_shift : 1UL << MINORBITS;
list_for_each_entry_safe(brd, next, &brd_devices, brd_list)
brd_del_one(brd);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-21 09:44:38 +0000