[PATCH 3/3] set block size to PAGE_SIZE and some cleanups
From: Nitin Gupta
Date: Wed Jan 27 2010 - 09:26:43 EST
ramzswap block size needs to be set to PAGE_SIZE
to avoid receiving any unaligned block I/O (happens
during swapon time). These unaligned access produce
unncessary I/O errors, scaring users.
Also included some minor cleanups.
Signed-off-by: Nitin Gupta <ngupta@xxxxxxxxxx>
---
drivers/staging/ramzswap/ramzswap_drv.c | 77 +++++++++++++++++------------
drivers/staging/ramzswap/ramzswap_drv.h | 2 +-
drivers/staging/ramzswap/ramzswap_ioctl.h | 2 +-
drivers/staging/ramzswap/xvmalloc.c | 2 +-
drivers/staging/ramzswap/xvmalloc.h | 2 +-
drivers/staging/ramzswap/xvmalloc_int.h | 2 +-
6 files changed, 50 insertions(+), 37 deletions(-)
diff --git a/drivers/staging/ramzswap/ramzswap_drv.c b/drivers/staging/ramzswap/ramzswap_drv.c
index 64f49c9..7f47373 100644
--- a/drivers/staging/ramzswap/ramzswap_drv.c
+++ b/drivers/staging/ramzswap/ramzswap_drv.c
@@ -1,7 +1,7 @@
/*
* Compressed RAM based swap device
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
@@ -220,7 +220,7 @@ out:
return ret;
}
-void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
+static void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
struct ramzswap_ioctl_stats *s)
{
strncpy(s->backing_swap_name, rzs->backing_swap_name,
@@ -502,6 +502,10 @@ static int setup_backing_swap(struct ramzswap *rzs)
goto bad_param;
}
disksize = i_size_read(inode);
+ if (!disksize) {
+ pr_err("Error reading backing swap size.\n");
+ goto bad_param;
+ }
} else if (S_ISREG(inode->i_mode)) {
bdev = inode->i_sb->s_bdev;
if (IS_SWAPFILE(inode)) {
@@ -519,7 +523,6 @@ static int setup_backing_swap(struct ramzswap *rzs)
rzs->swap_file = swap_file;
rzs->backing_swap = bdev;
rzs->disksize = disksize;
- BUG_ON(!rzs->disksize);
return 0;
@@ -537,7 +540,7 @@ out:
* Map logical page number 'pagenum' to physical page number
* on backing swap device. For block device, this is a nop.
*/
-u32 map_backing_swap_page(struct ramzswap *rzs, u32 pagenum)
+static u32 map_backing_swap_page(struct ramzswap *rzs, u32 pagenum)
{
u32 skip_pages, entries_per_page;
size_t delta, se_offset, skipped;
@@ -593,6 +596,10 @@ static void ramzswap_free_page(struct ramzswap *rzs, size_t index)
u32 offset = rzs->table[index].offset;
if (unlikely(!page)) {
+ /*
+ * No memory is allocated for zero filled pages.
+ * Simply clear zero page flag.
+ */
if (rzs_test_flag(rzs, index, RZS_ZERO)) {
rzs_clear_flag(rzs, index, RZS_ZERO);
stat_dec(&rzs->stats.pages_zero);
@@ -664,7 +671,6 @@ static int handle_uncompressed_page(struct ramzswap *rzs, struct bio *bio)
return 0;
}
-
/*
* Called when request page is not present in ramzswap.
* Its either in backing swap device (if present) or
@@ -782,24 +788,15 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
page = bio->bi_io_vec[0].bv_page;
index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT;
- src = rzs->compress_buffer;
-
/*
* System swaps to same sector again when the stored page
* is no longer referenced by any process. So, its now safe
* to free the memory that was allocated for this page.
*/
- if (rzs->table[index].page)
+ if (rzs->table[index].page || rzs_test_flag(rzs, index, RZS_ZERO))
ramzswap_free_page(rzs, index);
- /*
- * No memory is allocated for zero filled pages.
- * Simply clear zero page flag.
- */
- if (rzs_test_flag(rzs, index, RZS_ZERO)) {
- stat_dec(&rzs->stats.pages_zero);
- rzs_clear_flag(rzs, index, RZS_ZERO);
- }
+ src = rzs->compress_buffer;
mutex_lock(&rzs->lock);
@@ -941,7 +938,6 @@ out:
return 0;
}
-
/*
* Check if request is within bounds and page aligned.
*/
@@ -1069,6 +1065,7 @@ static void reset_device(struct ramzswap *rzs)
bd_release(rzs->backing_swap);
filp_close(rzs->swap_file, NULL);
rzs->backing_swap = NULL;
+ memset(rzs->backing_swap_name, 0, MAX_SWAP_NAME_LEN);
}
/* Reset stats */
@@ -1300,6 +1297,7 @@ static struct block_device_operations ramzswap_devops = {
static int create_device(struct ramzswap *rzs, int device_id)
{
+ int ret = 0;
mutex_init(&rzs->lock);
spin_lock_init(&rzs->stat64_lock);
INIT_LIST_HEAD(&rzs->backing_swap_extent_list);
@@ -1308,7 +1306,8 @@ static int create_device(struct ramzswap *rzs, int device_id)
if (!rzs->queue) {
pr_err("Error allocating disk queue for device %d\n",
device_id);
- return 0;
+ ret = -ENOMEM;
+ goto out;
}
blk_queue_make_request(rzs->queue, ramzswap_make_request);
@@ -1320,7 +1319,8 @@ static int create_device(struct ramzswap *rzs, int device_id)
blk_cleanup_queue(rzs->queue);
pr_warning("Error allocating disk structure for device %d\n",
device_id);
- return 0;
+ ret = -ENOMEM;
+ goto out;
}
rzs->disk->major = ramzswap_major;
@@ -1335,10 +1335,16 @@ static int create_device(struct ramzswap *rzs, int device_id)
* or set equal to backing swap device (if provided)
*/
set_capacity(rzs->disk, 0);
+
+ blk_queue_physical_block_size(rzs->disk->queue, PAGE_SIZE);
+ blk_queue_logical_block_size(rzs->disk->queue, PAGE_SIZE);
+
add_disk(rzs->disk);
rzs->init_done = 0;
- return 1;
+
+out:
+ return ret;
}
static void destroy_device(struct ramzswap *rzs)
@@ -1354,18 +1360,20 @@ static void destroy_device(struct ramzswap *rzs)
static int __init ramzswap_init(void)
{
- int i, ret;
+ int ret, dev_id;
if (num_devices > max_num_devices) {
pr_warning("Invalid value for num_devices: %u\n",
num_devices);
- return -EINVAL;
+ ret = -EINVAL;
+ goto out;
}
ramzswap_major = register_blkdev(0, "ramzswap");
if (ramzswap_major <= 0) {
pr_warning("Unable to get major number\n");
- return -EBUSY;
+ ret = -EBUSY;
+ goto out;
}
if (!num_devices) {
@@ -1376,21 +1384,26 @@ static int __init ramzswap_init(void)
/* Allocate the device array and initialize each one */
pr_info("Creating %u devices ...\n", num_devices);
devices = kzalloc(num_devices * sizeof(struct ramzswap), GFP_KERNEL);
- if (!devices)
- goto out;
+ if (!devices) {
+ ret = -ENOMEM;
+ goto unregister;
+ }
- for (i = 0; i < num_devices; i++)
- if (!create_device(&devices[i], i)) {
- ret = i;
+ for (dev_id = 0; dev_id < num_devices; dev_id++) {
+ if (create_device(&devices[dev_id], dev_id)) {
+ ret = -ENOMEM;
goto free_devices;
}
+ }
+
return 0;
+
free_devices:
- for (i = 0; i < ret; i++)
- destroy_device(&devices[i]);
-out:
- ret = -ENOMEM;
+ while (dev_id)
+ destroy_device(&devices[--dev_id]);
+unregister:
unregister_blkdev(ramzswap_major, "ramzswap");
+out:
return ret;
}
diff --git a/drivers/staging/ramzswap/ramzswap_drv.h b/drivers/staging/ramzswap/ramzswap_drv.h
index 3831d93..e5ffdce 100644
--- a/drivers/staging/ramzswap/ramzswap_drv.h
+++ b/drivers/staging/ramzswap/ramzswap_drv.h
@@ -1,7 +1,7 @@
/*
* Compressed RAM based swap device
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
diff --git a/drivers/staging/ramzswap/ramzswap_ioctl.h b/drivers/staging/ramzswap/ramzswap_ioctl.h
index 1edaeba..d26076d 100644
--- a/drivers/staging/ramzswap/ramzswap_ioctl.h
+++ b/drivers/staging/ramzswap/ramzswap_ioctl.h
@@ -1,7 +1,7 @@
/*
* Compressed RAM based swap device
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
diff --git a/drivers/staging/ramzswap/xvmalloc.c b/drivers/staging/ramzswap/xvmalloc.c
index dabd266..3fdbb8a 100644
--- a/drivers/staging/ramzswap/xvmalloc.c
+++ b/drivers/staging/ramzswap/xvmalloc.c
@@ -1,7 +1,7 @@
/*
* xvmalloc memory allocator
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
diff --git a/drivers/staging/ramzswap/xvmalloc.h b/drivers/staging/ramzswap/xvmalloc.h
index 010c6fe..5b1a81a 100644
--- a/drivers/staging/ramzswap/xvmalloc.h
+++ b/drivers/staging/ramzswap/xvmalloc.h
@@ -1,7 +1,7 @@
/*
* xvmalloc memory allocator
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
diff --git a/drivers/staging/ramzswap/xvmalloc_int.h b/drivers/staging/ramzswap/xvmalloc_int.h
index 263c72d..e23ed5c 100644
--- a/drivers/staging/ramzswap/xvmalloc_int.h
+++ b/drivers/staging/ramzswap/xvmalloc_int.h
@@ -1,7 +1,7 @@
/*
* xvmalloc memory allocator
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
--
1.6.2.5
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/