[PATCHv2 5/7] mtdblock: Dynamically allocate cache info structures
Ben Hutchings
bhutchings at solarflare.com
Tue Jan 12 18:09:25 EST 2010
Since we allocate struct mtd_blktrans_dev for each block device, we
can add our own structure members to the end. Therefore embed
struct mtd_blktrans_dev in struct mtdblk_dev and remove the static
array of struct mtdblk_dev. Also remove the redundant pointer to
struct mtd_info.
This is preparation for removing the static limit on the number of MTD
devices.
Signed-off-by: Ben Hutchings <bhutchings at solarflare.com>
---
drivers/mtd/mtdblock.c | 74 ++++++++++++++++++++----------------------------
1 files changed, 31 insertions(+), 43 deletions(-)
diff --git a/drivers/mtd/mtdblock.c b/drivers/mtd/mtdblock.c
index 9f41b1a..69f6bf2 100644
--- a/drivers/mtd/mtdblock.c
+++ b/drivers/mtd/mtdblock.c
@@ -19,15 +19,15 @@
#include <linux/mutex.h>
-static struct mtdblk_dev {
- struct mtd_info *mtd;
+struct mtdblk_dev {
+ struct mtd_blktrans_dev mbd;
int count;
struct mutex cache_mutex;
unsigned char *cache_data;
unsigned long cache_offset;
unsigned int cache_size;
enum { STATE_EMPTY, STATE_CLEAN, STATE_DIRTY } cache_state;
-} *mtdblks[MAX_MTD_DEVICES];
+};
static struct mutex mtdblks_lock;
@@ -98,7 +98,7 @@ static int erase_write (struct mtd_info *mtd, unsigned long pos,
static int write_cached_data (struct mtdblk_dev *mtdblk)
{
- struct mtd_info *mtd = mtdblk->mtd;
+ struct mtd_info *mtd = mtdblk->mbd.mtd;
int ret;
if (mtdblk->cache_state != STATE_DIRTY)
@@ -128,7 +128,7 @@ static int write_cached_data (struct mtdblk_dev *mtdblk)
static int do_cached_write (struct mtdblk_dev *mtdblk, unsigned long pos,
int len, const char *buf)
{
- struct mtd_info *mtd = mtdblk->mtd;
+ struct mtd_info *mtd = mtdblk->mbd.mtd;
unsigned int sect_size = mtdblk->cache_size;
size_t retlen;
int ret;
@@ -198,7 +198,7 @@ static int do_cached_write (struct mtdblk_dev *mtdblk, unsigned long pos,
static int do_cached_read (struct mtdblk_dev *mtdblk, unsigned long pos,
int len, char *buf)
{
- struct mtd_info *mtd = mtdblk->mtd;
+ struct mtd_info *mtd = mtdblk->mbd.mtd;
unsigned int sect_size = mtdblk->cache_size;
size_t retlen;
int ret;
@@ -244,16 +244,16 @@ static int do_cached_read (struct mtdblk_dev *mtdblk, unsigned long pos,
static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
unsigned long block, char *buf)
{
- struct mtdblk_dev *mtdblk = mtdblks[dev->devnum];
+ struct mtdblk_dev *mtdblk = container_of(dev, struct mtdblk_dev, mbd);
return do_cached_read(mtdblk, block<<9, 512, buf);
}
static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
unsigned long block, char *buf)
{
- struct mtdblk_dev *mtdblk = mtdblks[dev->devnum];
+ struct mtdblk_dev *mtdblk = container_of(dev, struct mtdblk_dev, mbd);
if (unlikely(!mtdblk->cache_data && mtdblk->cache_size)) {
- mtdblk->cache_data = vmalloc(mtdblk->mtd->erasesize);
+ mtdblk->cache_data = vmalloc(mtdblk->mbd.mtd->erasesize);
if (!mtdblk->cache_data)
return -EINTR;
/* -EINTR is not really correct, but it is the best match
@@ -266,37 +266,26 @@ static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
static int mtdblock_open(struct mtd_blktrans_dev *mbd)
{
- struct mtdblk_dev *mtdblk;
- struct mtd_info *mtd = mbd->mtd;
- int dev = mbd->devnum;
+ struct mtdblk_dev *mtdblk = container_of(mbd, struct mtdblk_dev, mbd);
DEBUG(MTD_DEBUG_LEVEL1,"mtdblock_open\n");
mutex_lock(&mtdblks_lock);
- if (mtdblks[dev]) {
- mtdblks[dev]->count++;
+ if (mtdblk->count) {
+ mtdblk->count++;
mutex_unlock(&mtdblks_lock);
return 0;
}
/* OK, it's not open. Create cache info for it */
- mtdblk = kzalloc(sizeof(struct mtdblk_dev), GFP_KERNEL);
- if (!mtdblk) {
- mutex_unlock(&mtdblks_lock);
- return -ENOMEM;
- }
-
mtdblk->count = 1;
- mtdblk->mtd = mtd;
-
mutex_init(&mtdblk->cache_mutex);
mtdblk->cache_state = STATE_EMPTY;
- if ( !(mtdblk->mtd->flags & MTD_NO_ERASE) && mtdblk->mtd->erasesize) {
- mtdblk->cache_size = mtdblk->mtd->erasesize;
+ if (!(mbd->mtd->flags & MTD_NO_ERASE) && mbd->mtd->erasesize) {
+ mtdblk->cache_size = mbd->mtd->erasesize;
mtdblk->cache_data = NULL;
}
- mtdblks[dev] = mtdblk;
mutex_unlock(&mtdblks_lock);
DEBUG(MTD_DEBUG_LEVEL1, "ok\n");
@@ -306,8 +295,7 @@ static int mtdblock_open(struct mtd_blktrans_dev *mbd)
static int mtdblock_release(struct mtd_blktrans_dev *mbd)
{
- int dev = mbd->devnum;
- struct mtdblk_dev *mtdblk = mtdblks[dev];
+ struct mtdblk_dev *mtdblk = container_of(mbd, struct mtdblk_dev, mbd);
DEBUG(MTD_DEBUG_LEVEL1, "mtdblock_release\n");
@@ -318,12 +306,10 @@ static int mtdblock_release(struct mtd_blktrans_dev *mbd)
mutex_unlock(&mtdblk->cache_mutex);
if (!--mtdblk->count) {
- /* It was the last usage. Free the device */
- mtdblks[dev] = NULL;
- if (mtdblk->mtd->sync)
- mtdblk->mtd->sync(mtdblk->mtd);
+ /* It was the last usage. Free the cache */
+ if (mbd->mtd->sync)
+ mbd->mtd->sync(mbd->mtd);
vfree(mtdblk->cache_data);
- kfree(mtdblk);
}
mutex_unlock(&mtdblks_lock);
@@ -335,40 +321,42 @@ static int mtdblock_release(struct mtd_blktrans_dev *mbd)
static int mtdblock_flush(struct mtd_blktrans_dev *dev)
{
- struct mtdblk_dev *mtdblk = mtdblks[dev->devnum];
+ struct mtdblk_dev *mtdblk = container_of(dev, struct mtdblk_dev, mbd);
mutex_lock(&mtdblk->cache_mutex);
write_cached_data(mtdblk);
mutex_unlock(&mtdblk->cache_mutex);
- if (mtdblk->mtd->sync)
- mtdblk->mtd->sync(mtdblk->mtd);
+ if (dev->mtd->sync)
+ dev->mtd->sync(dev->mtd);
return 0;
}
static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
{
- struct mtd_blktrans_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ struct mtdblk_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return;
- dev->mtd = mtd;
- dev->devnum = mtd->index;
+ dev->mbd.mtd = mtd;
+ dev->mbd.devnum = mtd->index;
- dev->size = mtd->size >> 9;
- dev->tr = tr;
+ dev->mbd.size = mtd->size >> 9;
+ dev->mbd.tr = tr;
if (!(mtd->flags & MTD_WRITEABLE))
- dev->readonly = 1;
+ dev->mbd.readonly = 1;
- add_mtd_blktrans_dev(dev);
+ add_mtd_blktrans_dev(&dev->mbd);
}
static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
{
+ struct mtdblk_dev *mtdblk = container_of(dev, struct mtdblk_dev, mbd);
+
del_mtd_blktrans_dev(dev);
- kfree(dev);
+ kfree(mtdblk);
}
static struct mtd_blktrans_ops mtdblock_tr = {
--
1.5.5
--
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
More information about the linux-mtd
mailing list