[patch 16/21] dcssblk: add >2G DCSSs support and stacked contiguous DCSSs support.

From: Martin Schwidefsky
Date: Wed Oct 01 2008 - 05:02:35 EST

From: Hongjie Yang <hongjie@xxxxxxxxxx>

The DCSS block device driver is modified to add >2G DCSSs support and
allow a DCSS block device to map to a set of contiguous DCSSs. The
extmem code is also modified to use new Diagnose x'64' subcodes for
>2G DCSSs.

Signed-off-by: Hongjie Yang <hongjie@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---

arch/s390/mm/extmem.c | 251 +++++++++++++++++---
drivers/s390/block/dcssblk.c | 515 ++++++++++++++++++++++++++++++++-----------
2 files changed, 596 insertions(+), 170 deletions(-)

Index: quilt-2.6/arch/s390/mm/extmem.c
===================================================================
--- quilt-2.6.orig/arch/s390/mm/extmem.c
+++ quilt-2.6/arch/s390/mm/extmem.c
@@ -43,20 +43,40 @@
#define DCSS_FINDSEG 0x0c
#define DCSS_LOADNOLY 0x10
#define DCSS_SEGEXT 0x18
+#define DCSS_LOADSHRX 0x20
+#define DCSS_LOADNSRX 0x24
+#define DCSS_FINDSEGX 0x2c
+#define DCSS_SEGEXTX 0x38
#define DCSS_FINDSEGA 0x0c

struct qrange {
- unsigned int start; // 3byte start address, 1 byte type
- unsigned int end; // 3byte end address, 1 byte reserved
+ unsigned long start; /* last byte type */
+ unsigned long end; /* last byte reserved */
};

struct qout64 {
+ unsigned long segstart;
+ unsigned long segend;
+ int segcnt;
+ int segrcnt;
+ struct qrange range[6];
+};
+
+#ifdef CONFIG_64BIT
+struct qrange_old {
+ unsigned int start; /* last byte type */
+ unsigned int end; /* last byte reserved */
+};
+
+/* output area format for the Diag x'64' old subcode x'18' */
+struct qout64_old {
int segstart;
int segend;
int segcnt;
int segrcnt;
- struct qrange range[6];
+ struct qrange_old range[6];
};
+#endif

struct qin64 {
char qopcode;
@@ -86,6 +106,55 @@ static DEFINE_MUTEX(dcss_lock);
static LIST_HEAD(dcss_list);
static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
"EW/EN-MIXED" };
+static int loadshr_scode, loadnsr_scode, findseg_scode;
+static int segext_scode, purgeseg_scode;
+static int scode_set;
+
+/* set correct Diag x'64' subcodes. */
+static int
+dcss_set_subcodes(void)
+{
+#ifdef CONFIG_64BIT
+ char *name = kmalloc(8 * sizeof(char), GFP_DMA);
+ unsigned long rx, ry;
+ int rc;
+
+ if (name == NULL)
+ return -ENOMEM;
+
+ rx = (unsigned long) name;
+ ry = DCSS_FINDSEGX;
+
+ strcpy(name, "dummy");
+ asm volatile(
+ " diag %0,%1,0x64\n"
+ "0: ipm %2\n"
+ " srl %2,28\n"
+ " j 2f\n"
+ "1: la %2,3\n"
+ "2:\n"
+ EX_TABLE(0b, 1b)
+ : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
+
+ kfree(name);
+ /* Diag x'64' new subcodes are supported, set to new subcodes */
+ if (rc != 3) {
+ loadshr_scode = DCSS_LOADSHRX;
+ loadnsr_scode = DCSS_LOADNSRX;
+ purgeseg_scode = DCSS_PURGESEG;
+ findseg_scode = DCSS_FINDSEGX;
+ segext_scode = DCSS_SEGEXTX;
+ return 0;
+ }
+#endif
+ /* Diag x'64' new subcodes are not supported, set to old subcodes */
+ loadshr_scode = DCSS_LOADNOLY;
+ loadnsr_scode = DCSS_LOADNSR;
+ purgeseg_scode = DCSS_PURGESEG;
+ findseg_scode = DCSS_FINDSEG;
+ segext_scode = DCSS_SEGEXT;
+ return 0;
+}

/*
* Create the 8 bytes, ebcdic VM segment name from
@@ -135,25 +204,45 @@ segment_by_name (char *name)
* Perform a function on a dcss segment.
*/
static inline int
-dcss_diag (__u8 func, void *parameter,
+dcss_diag(int *func, void *parameter,
unsigned long *ret1, unsigned long *ret2)
{
unsigned long rx, ry;
int rc;

+ if (scode_set == 0) {
+ rc = dcss_set_subcodes();
+ if (rc < 0)
+ return rc;
+ scode_set = 1;
+ }
rx = (unsigned long) parameter;
- ry = (unsigned long) func;
- asm volatile(
+ ry = (unsigned long) *func;
+
#ifdef CONFIG_64BIT
- " sam31\n"
- " diag %0,%1,0x64\n"
- " sam64\n"
+ /* 64-bit Diag x'64' new subcode, keep in 64-bit addressing mode */
+ if (*func > DCSS_SEGEXT)
+ asm volatile(
+ " diag %0,%1,0x64\n"
+ " ipm %2\n"
+ " srl %2,28\n"
+ : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
+ /* 31-bit Diag x'64' old subcode, switch to 31-bit addressing mode */
+ else
+ asm volatile(
+ " sam31\n"
+ " diag %0,%1,0x64\n"
+ " sam64\n"
+ " ipm %2\n"
+ " srl %2,28\n"
+ : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
#else
+ asm volatile(
" diag %0,%1,0x64\n"
-#endif
" ipm %2\n"
" srl %2,28\n"
: "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
+#endif
*ret1 = rx;
*ret2 = ry;
return rc;
@@ -190,14 +279,45 @@ query_segment_type (struct dcss_segment
qin->qoutlen = sizeof(struct qout64);
memcpy (qin->qname, seg->dcss_name, 8);

- diag_cc = dcss_diag (DCSS_SEGEXT, qin, &dummy, &vmrc);
+ diag_cc = dcss_diag(&segext_scode, qin, &dummy, &vmrc);

+ if (diag_cc < 0) {
+ rc = diag_cc;
+ goto out_free;
+ }
if (diag_cc > 1) {
PRINT_WARN ("segment_type: diag returned error %ld\n", vmrc);
rc = dcss_diag_translate_rc (vmrc);
goto out_free;
}

+#ifdef CONFIG_64BIT
+ /* Only old format of output area of Diagnose x'64' is supported,
+ copy data for the new format. */
+ if (segext_scode == DCSS_SEGEXT) {
+ struct qout64_old *qout_old;
+ qout_old = kzalloc(sizeof(struct qout64_old), GFP_DMA);
+ if (qout_old == NULL) {
+ rc = -ENOMEM;
+ goto out_free;
+ }
+ memcpy(qout_old, qout, sizeof(struct qout64_old));
+ qout->segstart = (unsigned long) qout_old->segstart;
+ qout->segend = (unsigned long) qout_old->segend;
+ qout->segcnt = qout_old->segcnt;
+ qout->segrcnt = qout_old->segrcnt;
+
+ if (qout->segcnt > 6)
+ qout->segrcnt = 6;
+ for (i = 0; i < qout->segrcnt; i++) {
+ qout->range[i].start =
+ (unsigned long) qout_old->range[i].start;
+ qout->range[i].end =
+ (unsigned long) qout_old->range[i].end;
+ }
+ kfree(qout_old);
+ }
+#endif
if (qout->segcnt > 6) {
rc = -ENOTSUPP;
goto out_free;
@@ -269,6 +389,30 @@ segment_type (char* name)
}

/*
+ * check if segment collides with other segments that are currently loaded
+ * returns 1 if this is the case, 0 if no collision was found
+ */
+static int
+segment_overlaps_others (struct dcss_segment *seg)
+{
+ struct list_head *l;
+ struct dcss_segment *tmp;
+
+ BUG_ON(!mutex_is_locked(&dcss_lock));
+ list_for_each(l, &dcss_list) {
+ tmp = list_entry(l, struct dcss_segment, list);
+ if ((tmp->start_addr >> 20) > (seg->end >> 20))
+ continue;
+ if ((tmp->end >> 20) < (seg->start_addr >> 20))
+ continue;
+ if (seg == tmp)
+ continue;
+ return 1;
+ }
+ return 0;
+}
+
+/*
* real segment loading function, called from segment_load
*/
static int
@@ -276,7 +420,8 @@ __segment_load (char *name, int do_nonsh
{
struct dcss_segment *seg = kmalloc(sizeof(struct dcss_segment),
GFP_DMA);
- int dcss_command, rc, diag_cc;
+ int rc, diag_cc;
+ unsigned long start_addr, end_addr, dummy;

if (seg == NULL) {
rc = -ENOMEM;
@@ -287,6 +432,13 @@ __segment_load (char *name, int do_nonsh
if (rc < 0)
goto out_free;

+ if (loadshr_scode == DCSS_LOADSHRX) {
+ if (segment_overlaps_others(seg)) {
+ rc = -EBUSY;
+ goto out_free;
+ }
+ }
+
rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1);

if (rc)
@@ -316,20 +468,28 @@ __segment_load (char *name, int do_nonsh
}

if (do_nonshared)
- dcss_command = DCSS_LOADNSR;
+ diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
+ &start_addr, &end_addr);
else
- dcss_command = DCSS_LOADNOLY;
-
- diag_cc = dcss_diag(dcss_command, seg->dcss_name,
- &seg->start_addr, &seg->end);
+ diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
+ &start_addr, &end_addr);
+ if (diag_cc < 0) {
+ dcss_diag(&purgeseg_scode, seg->dcss_name,
+ &dummy, &dummy);
+ rc = diag_cc;
+ goto out_resource;
+ }
if (diag_cc > 1) {
PRINT_WARN ("segment_load: could not load segment %s - "
- "diag returned error (%ld)\n",name,seg->end);
- rc = dcss_diag_translate_rc (seg->end);
- dcss_diag(DCSS_PURGESEG, seg->dcss_name,
- &seg->start_addr, &seg->end);
+ "diag returned error (%ld)\n",
+ name, end_addr);
+ rc = dcss_diag_translate_rc(end_addr);
+ dcss_diag(&purgeseg_scode, seg->dcss_name,
+ &dummy, &dummy);
goto out_resource;
}
+ seg->start_addr = start_addr;
+ seg->end = end_addr;
seg->do_nonshared = do_nonshared;
atomic_set(&seg->ref_count, 1);
list_add(&seg->list, &dcss_list);
@@ -423,8 +583,8 @@ int
segment_modify_shared (char *name, int do_nonshared)
{
struct dcss_segment *seg;
- unsigned long dummy;
- int dcss_command, rc, diag_cc;
+ unsigned long start_addr, end_addr, dummy;
+ int rc, diag_cc;

mutex_lock(&dcss_lock);
seg = segment_by_name (name);
@@ -445,38 +605,51 @@ segment_modify_shared (char *name, int d
goto out_unlock;
}
release_resource(seg->res);
- if (do_nonshared) {
- dcss_command = DCSS_LOADNSR;
+ if (do_nonshared)
seg->res->flags &= ~IORESOURCE_READONLY;
- } else {
- dcss_command = DCSS_LOADNOLY;
+ else
if (seg->vm_segtype == SEG_TYPE_SR ||
seg->vm_segtype == SEG_TYPE_ER)
seg->res->flags |= IORESOURCE_READONLY;
- }
+
if (request_resource(&iomem_resource, seg->res)) {
PRINT_WARN("segment_modify_shared: could not reload segment %s"
" - overlapping resources\n", name);
rc = -EBUSY;
kfree(seg->res);
- goto out_del;
+ goto out_del_mem;
+ }
+
+ dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
+ if (do_nonshared)
+ diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
+ &start_addr, &end_addr);
+ else
+ diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
+ &start_addr, &end_addr);
+ if (diag_cc < 0) {
+ rc = diag_cc;
+ goto out_del_res;
}
- dcss_diag(DCSS_PURGESEG, seg->dcss_name, &dummy, &dummy);
- diag_cc = dcss_diag(dcss_command, seg->dcss_name,
- &seg->start_addr, &seg->end);
if (diag_cc > 1) {
PRINT_WARN ("segment_modify_shared: could not reload segment %s"
- " - diag returned error (%ld)\n",name,seg->end);
- rc = dcss_diag_translate_rc (seg->end);
- goto out_del;
+ " - diag returned error (%ld)\n",
+ name, end_addr);
+ rc = dcss_diag_translate_rc(end_addr);
+ goto out_del_res;
}
+ seg->start_addr = start_addr;
+ seg->end = end_addr;
seg->do_nonshared = do_nonshared;
rc = 0;
goto out_unlock;
- out_del:
+ out_del_res:
+ release_resource(seg->res);
+ kfree(seg->res);
+ out_del_mem:
vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
list_del(&seg->list);
- dcss_diag(DCSS_PURGESEG, seg->dcss_name, &dummy, &dummy);
+ dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
kfree(seg);
out_unlock:
mutex_unlock(&dcss_lock);
@@ -510,7 +683,7 @@ segment_unload(char *name)
kfree(seg->res);
vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
list_del(&seg->list);
- dcss_diag(DCSS_PURGESEG, seg->dcss_name, &dummy, &dummy);
+ dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
kfree(seg);
out_unlock:
mutex_unlock(&dcss_lock);
@@ -545,7 +718,7 @@ segment_save(char *name)
endpfn = (seg->end) >> PAGE_SHIFT;
sprintf(cmd1, "DEFSEG %s", name);
for (i=0; i<seg->segcnt; i++) {
- sprintf(cmd1+strlen(cmd1), " %X-%X %s",
+ sprintf(cmd1+strlen(cmd1), " %lX-%lX %s",
seg->range[i].start >> PAGE_SHIFT,
seg->range[i].end >> PAGE_SHIFT,
segtype_string[seg->range[i].start & 0xff]);
Index: quilt-2.6/drivers/s390/block/dcssblk.c
===================================================================
--- quilt-2.6.orig/drivers/s390/block/dcssblk.c
+++ quilt-2.6/drivers/s390/block/dcssblk.c
@@ -31,7 +31,6 @@
#define PRINT_WARN(x...) printk(KERN_WARNING DCSSBLK_NAME " warning: " x)
#define PRINT_ERR(x...) printk(KERN_ERR DCSSBLK_NAME " error: " x)

-
static int dcssblk_open(struct inode *inode, struct file *filp);
static int dcssblk_release(struct inode *inode, struct file *filp);
static int dcssblk_make_request(struct request_queue *q, struct bio *bio);
@@ -48,6 +47,30 @@ static struct block_device_operations dc
.direct_access = dcssblk_direct_access,
};

+struct dcssblk_dev_info {
+ struct list_head lh;
+ struct device dev;
+ char segment_name[BUS_ID_SIZE];
+ atomic_t use_count;
+ struct gendisk *gd;
+ unsigned long start;
+ unsigned long end;
+ int segment_type;
+ unsigned char save_pending;
+ unsigned char is_shared;
+ struct request_queue *dcssblk_queue;
+ int num_of_segments;
+ struct list_head seg_list;
+};
+
+struct segment_info {
+ struct list_head lh;
+ char segment_name[BUS_ID_SIZE];
+ unsigned long start;
+ unsigned long end;
+ int segment_type;
+};
+
static ssize_t dcssblk_add_store(struct device * dev, struct device_attribute *attr, const char * buf,
size_t count);
static ssize_t dcssblk_remove_store(struct device * dev, struct device_attribute *attr, const char * buf,
@@ -58,30 +81,20 @@ static ssize_t dcssblk_save_show(struct
static ssize_t dcssblk_shared_store(struct device * dev, struct device_attribute *attr, const char * buf,
size_t count);
static ssize_t dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf);
+static ssize_t dcssblk_seglist_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf);

static DEVICE_ATTR(add, S_IWUSR, NULL, dcssblk_add_store);
static DEVICE_ATTR(remove, S_IWUSR, NULL, dcssblk_remove_store);
-static DEVICE_ATTR(save, S_IWUSR | S_IRUGO, dcssblk_save_show,
+static DEVICE_ATTR(save, S_IWUSR | S_IRUSR, dcssblk_save_show,
dcssblk_save_store);
-static DEVICE_ATTR(shared, S_IWUSR | S_IRUGO, dcssblk_shared_show,
+static DEVICE_ATTR(shared, S_IWUSR | S_IRUSR, dcssblk_shared_show,
dcssblk_shared_store);
+static DEVICE_ATTR(seglist, S_IRUSR, dcssblk_seglist_show, NULL);

static struct device *dcssblk_root_dev;

-struct dcssblk_dev_info {
- struct list_head lh;
- struct device dev;
- char segment_name[BUS_ID_SIZE];
- atomic_t use_count;
- struct gendisk *gd;
- unsigned long start;
- unsigned long end;
- int segment_type;
- unsigned char save_pending;
- unsigned char is_shared;
- struct request_queue *dcssblk_queue;
-};
-
static LIST_HEAD(dcssblk_devices);
static struct rw_semaphore dcssblk_devices_sem;

@@ -91,8 +104,15 @@ static struct rw_semaphore dcssblk_devic
static void
dcssblk_release_segment(struct device *dev)
{
- PRINT_DEBUG("segment release fn called for %s\n", dev_name(dev));
- kfree(container_of(dev, struct dcssblk_dev_info, dev));
+ struct dcssblk_dev_info *dev_info;
+ struct segment_info *entry, *temp;
+
+ dev_info = container_of(dev, struct dcssblk_dev_info, dev);
+ list_for_each_entry_safe(entry, temp, &dev_info->seg_list, lh) {
+ list_del(&entry->lh);
+ kfree(entry);
+ }
+ kfree(dev_info);
module_put(THIS_MODULE);
}

@@ -142,6 +162,169 @@ dcssblk_get_device_by_name(char *name)
return NULL;
}

+/*
+ * get the struct segment_info from seg_list
+ * for the given name.
+ * down_read(&dcssblk_devices_sem) must be held.
+ */
+static struct segment_info *
+dcssblk_get_segment_by_name(char *name)
+{
+ struct dcssblk_dev_info *dev_info;
+ struct segment_info *entry;
+
+ list_for_each_entry(dev_info, &dcssblk_devices, lh) {
+ list_for_each_entry(entry, &dev_info->seg_list, lh) {
+ if (!strcmp(name, entry->segment_name))
+ return entry;
+ }
+ }
+ return NULL;
+}
+
+/*
+ * get the highest address of the multi-segment block.
+ */
+static unsigned long
+dcssblk_find_highest_addr(struct dcssblk_dev_info *dev_info)
+{
+ unsigned long highest_addr;
+ struct segment_info *entry;
+
+ highest_addr = 0;
+ list_for_each_entry(entry, &dev_info->seg_list, lh) {
+ if (highest_addr < entry->end)
+ highest_addr = entry->end;
+ }
+ return highest_addr;
+}
+
+/*
+ * get the lowest address of the multi-segment block.
+ */
+static unsigned long
+dcssblk_find_lowest_addr(struct dcssblk_dev_info *dev_info)
+{
+ int set_first;
+ unsigned long lowest_addr;
+ struct segment_info *entry;
+
+ set_first = 0;
+ lowest_addr = 0;
+ list_for_each_entry(entry, &dev_info->seg_list, lh) {
+ if (set_first == 0) {
+ lowest_addr = entry->start;
+ set_first = 1;
+ } else {
+ if (lowest_addr > entry->start)
+ lowest_addr = entry->start;
+ }
+ }
+ return lowest_addr;
+}
+
+/*
+ * Check continuity of segments.
+ */
+static int
+dcssblk_is_continuous(struct dcssblk_dev_info *dev_info)
+{
+ int i, j, rc;
+ struct segment_info *sort_list, *entry, temp;
+
+ if (dev_info->num_of_segments <= 1)
+ return 0;
+
+ sort_list = kzalloc(
+ sizeof(struct segment_info) * dev_info->num_of_segments,
+ GFP_KERNEL);
+ if (sort_list == NULL)
+ return -ENOMEM;
+ i = 0;
+ list_for_each_entry(entry, &dev_info->seg_list, lh) {
+ memcpy(&sort_list[i], entry, sizeof(struct segment_info));
+ i++;
+ }
+
+ /* sort segments */
+ for (i = 0; i < dev_info->num_of_segments; i++)
+ for (j = 0; j < dev_info->num_of_segments; j++)
+ if (sort_list[j].start > sort_list[i].start) {
+ memcpy(&temp, &sort_list[i],
+ sizeof(struct segment_info));
+ memcpy(&sort_list[i], &sort_list[j],
+ sizeof(struct segment_info));
+ memcpy(&sort_list[j], &temp,
+ sizeof(struct segment_info));
+ }
+
+ /* check continuity */
+ for (i = 0; i < dev_info->num_of_segments - 1; i++) {
+ if ((sort_list[i].end + 1) != sort_list[i+1].start) {
+ PRINT_ERR("Segment %s is not contiguous with "
+ "segment %s\n",
+ sort_list[i].segment_name,
+ sort_list[i+1].segment_name);
+ rc = -EINVAL;
+ goto out;
+ }
+ /* EN and EW are allowed in a block device */
+ if (sort_list[i].segment_type != sort_list[i+1].segment_type) {
+ if (!(sort_list[i].segment_type & SEGMENT_EXCLUSIVE) ||
+ (sort_list[i].segment_type == SEG_TYPE_ER) ||
+ !(sort_list[i+1].segment_type &
+ SEGMENT_EXCLUSIVE) ||
+ (sort_list[i+1].segment_type == SEG_TYPE_ER)) {
+ PRINT_ERR("Segment %s has different type from "
+ "segment %s\n",
+ sort_list[i].segment_name,
+ sort_list[i+1].segment_name);
+ rc = -EINVAL;
+ goto out;
+ }
+ }
+ }
+ rc = 0;
+out:
+ kfree(sort_list);
+ return rc;
+}
+
+/*
+ * Load a segment
+ */
+static int
+dcssblk_load_segment(char *name, struct segment_info **seg_info)
+{
+ int rc;
+
+ /* already loaded? */
+ down_read(&dcssblk_devices_sem);
+ *seg_info = dcssblk_get_segment_by_name(name);
+ up_read(&dcssblk_devices_sem);
+ if (*seg_info != NULL)
+ return -EEXIST;
+
+ /* get a struct segment_info */
+ *seg_info = kzalloc(sizeof(struct segment_info), GFP_KERNEL);
+ if (*seg_info == NULL)
+ return -ENOMEM;
+
+ strcpy((*seg_info)->segment_name, name);
+
+ /* load the segment */
+ rc = segment_load(name, SEGMENT_SHARED,
+ &(*seg_info)->start, &(*seg_info)->end);
+ if (rc < 0) {
+ segment_warning(rc, (*seg_info)->segment_name);
+ kfree(*seg_info);
+ } else {
+ INIT_LIST_HEAD(&(*seg_info)->lh);
+ (*seg_info)->segment_type = rc;
+ }
+ return rc;
+}
+
static void dcssblk_unregister_callback(struct device *dev)
{
device_unregister(dev);
@@ -165,6 +348,7 @@ static ssize_t
dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count)
{
struct dcssblk_dev_info *dev_info;
+ struct segment_info *entry, *temp;
int rc;

if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0'))
@@ -172,46 +356,46 @@ dcssblk_shared_store(struct device *dev,
down_write(&dcssblk_devices_sem);
dev_info = container_of(dev, struct dcssblk_dev_info, dev);
if (atomic_read(&dev_info->use_count)) {
- PRINT_ERR("share: segment %s is busy!\n",
- dev_info->segment_name);
rc = -EBUSY;
goto out;
}
if (inbuf[0] == '1') {
- // reload segment in shared mode
- rc = segment_modify_shared(dev_info->segment_name,
- SEGMENT_SHARED);
- if (rc < 0) {
- BUG_ON(rc == -EINVAL);
- if (rc != -EAGAIN)
- goto removeseg;
- } else {
- dev_info->is_shared = 1;
- switch (dev_info->segment_type) {
- case SEG_TYPE_SR:
- case SEG_TYPE_ER:
- case SEG_TYPE_SC:
- set_disk_ro(dev_info->gd,1);
+ /* reload segments in shared mode */
+ list_for_each_entry(entry, &dev_info->seg_list, lh) {
+ rc = segment_modify_shared(entry->segment_name,
+ SEGMENT_SHARED);
+ if (rc < 0) {
+ BUG_ON(rc == -EINVAL);
+ if (rc != -EAGAIN)
+ goto removeseg;
}
}
+ dev_info->is_shared = 1;
+ switch (dev_info->segment_type) {
+ case SEG_TYPE_SR:
+ case SEG_TYPE_ER:
+ case SEG_TYPE_SC:
+ set_disk_ro(dev_info->gd, 1);
+ }
} else if (inbuf[0] == '0') {
- // reload segment in exclusive mode
+ /* reload segments in exclusive mode */
if (dev_info->segment_type == SEG_TYPE_SC) {
PRINT_ERR("Segment type SC (%s) cannot be loaded in "
- "non-shared mode\n", dev_info->segment_name);
+ "non-shared mode\n", dev_info->segment_name);
rc = -EINVAL;
goto out;
}
- rc = segment_modify_shared(dev_info->segment_name,
- SEGMENT_EXCLUSIVE);
- if (rc < 0) {
- BUG_ON(rc == -EINVAL);
- if (rc != -EAGAIN)
- goto removeseg;
- } else {
- dev_info->is_shared = 0;
- set_disk_ro(dev_info->gd, 0);
+ list_for_each_entry(entry, &dev_info->seg_list, lh) {
+ rc = segment_modify_shared(entry->segment_name,
+ SEGMENT_EXCLUSIVE);
+ if (rc < 0) {
+ BUG_ON(rc == -EINVAL);
+ if (rc != -EAGAIN)
+ goto removeseg;
+ }
}
+ dev_info->is_shared = 0;
+ set_disk_ro(dev_info->gd, 0);
} else {
rc = -EINVAL;
goto out;
@@ -220,8 +404,14 @@ dcssblk_shared_store(struct device *dev,
goto out;

removeseg:
- PRINT_ERR("Could not reload segment %s, removing it now!\n",
- dev_info->segment_name);
+ PRINT_ERR("Could not reload segment(s) of the device %s, removing "
+ "segment(s) now!\n",
+ dev_info->segment_name);
+ temp = entry;
+ list_for_each_entry(entry, &dev_info->seg_list, lh) {
+ if (entry != temp)
+ segment_unload(entry->segment_name);
+ }
list_del(&dev_info->lh);

del_gendisk(dev_info->gd);
@@ -254,6 +444,7 @@ static ssize_t
dcssblk_save_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count)
{
struct dcssblk_dev_info *dev_info;
+ struct segment_info *entry;

if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0'))
return -EINVAL;
@@ -263,14 +454,16 @@ dcssblk_save_store(struct device *dev, s
if (inbuf[0] == '1') {
if (atomic_read(&dev_info->use_count) == 0) {
// device is idle => we save immediately
- PRINT_INFO("Saving segment %s\n",
+ PRINT_INFO("Saving segment(s) of the device %s\n",
dev_info->segment_name);
- segment_save(dev_info->segment_name);
+ list_for_each_entry(entry, &dev_info->seg_list, lh) {
+ segment_save(entry->segment_name);
+ }
} else {
// device is busy => we save it when it becomes
// idle in dcssblk_release
- PRINT_INFO("Segment %s is currently busy, it will "
- "be saved when it becomes idle...\n",
+ PRINT_INFO("Device %s is currently busy, segment(s) "
+ "will be saved when it becomes idle...\n",
dev_info->segment_name);
dev_info->save_pending = 1;
}
@@ -279,7 +472,8 @@ dcssblk_save_store(struct device *dev, s
// device is busy & the user wants to undo his save
// request
dev_info->save_pending = 0;
- PRINT_INFO("Pending save for segment %s deactivated\n",
+ PRINT_INFO("Pending save for segment(s) of the device "
+ "%s deactivated\n",
dev_info->segment_name);
}
} else {
@@ -291,66 +485,123 @@ dcssblk_save_store(struct device *dev, s
}

/*
+ * device attribute for showing all segments in a device
+ */
+static ssize_t
+dcssblk_seglist_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ int i;
+
+ struct dcssblk_dev_info *dev_info;
+ struct segment_info *entry;
+
+ down_read(&dcssblk_devices_sem);
+ dev_info = container_of(dev, struct dcssblk_dev_info, dev);
+ i = 0;
+ buf[0] = '\0';
+ list_for_each_entry(entry, &dev_info->seg_list, lh) {
+ strcpy(&buf[i], entry->segment_name);
+ i += strlen(entry->segment_name);
+ buf[i] = '\n';
+ i++;
+ }
+ up_read(&dcssblk_devices_sem);
+ return i;
+}
+
+/*
* device attribute for adding devices
*/
static ssize_t
dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
- int rc, i;
+ int rc, i, j, num_of_segments;
struct dcssblk_dev_info *dev_info;
+ struct segment_info *seg_info, *temp;
char *local_buf;
unsigned long seg_byte_size;

dev_info = NULL;
+ seg_info = NULL;
if (dev != dcssblk_root_dev) {
rc = -EINVAL;
goto out_nobuf;
}
+ if ((count < 1) || (buf[0] == '\0') || (buf[0] == '\n')) {
+ rc = -ENAMETOOLONG;
+ goto out_nobuf;
+ }
+
local_buf = kmalloc(count + 1, GFP_KERNEL);
if (local_buf == NULL) {
rc = -ENOMEM;
goto out_nobuf;
}
+
/*
* parse input
*/
+ num_of_segments = 0;
for (i = 0; ((buf[i] != '\0') && (buf[i] != '\n') && i < count); i++) {
- local_buf[i] = toupper(buf[i]);
+ for (j = i; (buf[j] != ':') &&
+ (buf[j] != '\0') &&
+ (buf[j] != '\n') &&
+ j < count; j++) {
+ local_buf[j-i] = toupper(buf[j]);
+ }
+ local_buf[j-i] = '\0';
+ if (((j - i) == 0) || ((j - i) > 8)) {
+ rc = -ENAMETOOLONG;
+ goto seg_list_del;
+ }
+
+ rc = dcssblk_load_segment(local_buf, &seg_info);
+ if (rc < 0)
+ goto seg_list_del;
+ /*
+ * get a struct dcssblk_dev_info
+ */
+ if (num_of_segments == 0) {
+ dev_info = kzalloc(sizeof(struct dcssblk_dev_info),
+ GFP_KERNEL);
+ if (dev_info == NULL) {
+ rc = -ENOMEM;
+ goto out;
+ }
+ strcpy(dev_info->segment_name, local_buf);
+ dev_info->segment_type = seg_info->segment_type;
+ INIT_LIST_HEAD(&dev_info->seg_list);
+ }
+ list_add_tail(&seg_info->lh, &dev_info->seg_list);
+ num_of_segments++;
+ i = j;
+
+ if ((buf[j] == '\0') || (buf[j] == '\n'))
+ break;
}
- local_buf[i] = '\0';
- if ((i == 0) || (i > 8)) {
+
+ /* no trailing colon at the end of the input */
+ if ((i > 0) && (buf[i-1] == ':')) {
rc = -ENAMETOOLONG;
- goto out;
- }
- /*
- * already loaded?
- */
- down_read(&dcssblk_devices_sem);
- dev_info = dcssblk_get_device_by_name(local_buf);
- up_read(&dcssblk_devices_sem);
- if (dev_info != NULL) {
- PRINT_WARN("Segment %s already loaded!\n", local_buf);
- rc = -EEXIST;
- goto out;
- }
- /*
- * get a struct dcssblk_dev_info
- */
- dev_info = kzalloc(sizeof(struct dcssblk_dev_info), GFP_KERNEL);
- if (dev_info == NULL) {
- rc = -ENOMEM;
- goto out;
+ goto seg_list_del;
}
+ strlcpy(local_buf, buf, i + 1);
+ dev_info->num_of_segments = num_of_segments;
+ rc = dcssblk_is_continuous(dev_info);
+ if (rc < 0)
+ goto seg_list_del;

- strcpy(dev_info->segment_name, local_buf);
- dev_set_name(&dev_info->dev, local_buf);
+ dev_info->start = dcssblk_find_lowest_addr(dev_info);
+ dev_info->end = dcssblk_find_highest_addr(dev_info);
+
+ dev_set_name(&dev_info->dev, dev_info->segment_name);
dev_info->dev.release = dcssblk_release_segment;
INIT_LIST_HEAD(&dev_info->lh);
-
dev_info->gd = alloc_disk(DCSSBLK_MINORS_PER_DISK);
if (dev_info->gd == NULL) {
rc = -ENOMEM;
- goto free_dev_info;
+ goto seg_list_del;
}
dev_info->gd->major = dcssblk_major;
dev_info->gd->fops = &dcssblk_devops;
@@ -360,59 +611,43 @@ dcssblk_add_store(struct device *dev, st
dev_info->gd->driverfs_dev = &dev_info->dev;
blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request);
blk_queue_hardsect_size(dev_info->dcssblk_queue, 4096);
- /*
- * load the segment
- */
- rc = segment_load(local_buf, SEGMENT_SHARED,
- &dev_info->start, &dev_info->end);
- if (rc < 0) {
- segment_warning(rc, dev_info->segment_name);
- goto dealloc_gendisk;
- }
+
seg_byte_size = (dev_info->end - dev_info->start + 1);
set_capacity(dev_info->gd, seg_byte_size >> 9); // size in sectors
- PRINT_INFO("Loaded segment %s, size = %lu Byte, "
+ PRINT_INFO("Loaded segment(s) %s, size = %lu Byte, "
"capacity = %lu (512 Byte) sectors\n", local_buf,
seg_byte_size, seg_byte_size >> 9);

- dev_info->segment_type = rc;
dev_info->save_pending = 0;
dev_info->is_shared = 1;
dev_info->dev.parent = dcssblk_root_dev;

/*
- * get minor, add to list
+ *get minor, add to list
*/
down_write(&dcssblk_devices_sem);
- if (dcssblk_get_device_by_name(local_buf)) {
- up_write(&dcssblk_devices_sem);
+ if (dcssblk_get_segment_by_name(local_buf)) {
rc = -EEXIST;
- goto unload_seg;
+ goto release_gd;
}
rc = dcssblk_assign_free_minor(dev_info);
- if (rc) {
- up_write(&dcssblk_devices_sem);
- PRINT_ERR("No free minor number available! "
- "Unloading segment...\n");
- goto unload_seg;
- }
+ if (rc)
+ goto release_gd;
sprintf(dev_info->gd->disk_name, "dcssblk%d",
dev_info->gd->first_minor);
list_add_tail(&dev_info->lh, &dcssblk_devices);

if (!try_module_get(THIS_MODULE)) {
rc = -ENODEV;
- goto list_del;
+ goto dev_list_del;
}
/*
* register the device
*/
rc = device_register(&dev_info->dev);
if (rc) {
- PRINT_ERR("Segment %s could not be registered RC=%d\n",
- local_buf, rc);
module_put(THIS_MODULE);
- goto list_del;
+ goto dev_list_del;
}
get_device(&dev_info->dev);
rc = device_create_file(&dev_info->dev, &dev_attr_shared);
@@ -421,6 +656,9 @@ dcssblk_add_store(struct device *dev, st
rc = device_create_file(&dev_info->dev, &dev_attr_save);
if (rc)
goto unregister_dev;
+ rc = device_create_file(&dev_info->dev, &dev_attr_seglist);
+ if (rc)
+ goto unregister_dev;

add_disk(dev_info->gd);

@@ -434,7 +672,6 @@ dcssblk_add_store(struct device *dev, st
set_disk_ro(dev_info->gd,0);
break;
}
- PRINT_DEBUG("Segment %s loaded successfully\n", local_buf);
up_write(&dcssblk_devices_sem);
rc = count;
goto out;
@@ -445,20 +682,27 @@ unregister_dev:
dev_info->gd->queue = NULL;
put_disk(dev_info->gd);
device_unregister(&dev_info->dev);
- segment_unload(dev_info->segment_name);
+ list_for_each_entry(seg_info, &dev_info->seg_list, lh) {
+ segment_unload(seg_info->segment_name);
+ }
put_device(&dev_info->dev);
up_write(&dcssblk_devices_sem);
goto out;
-list_del:
+dev_list_del:
list_del(&dev_info->lh);
- up_write(&dcssblk_devices_sem);
-unload_seg:
- segment_unload(local_buf);
-dealloc_gendisk:
+release_gd:
blk_cleanup_queue(dev_info->dcssblk_queue);
dev_info->gd->queue = NULL;
put_disk(dev_info->gd);
-free_dev_info:
+ up_write(&dcssblk_devices_sem);
+seg_list_del:
+ if (dev_info == NULL)
+ goto out;
+ list_for_each_entry_safe(seg_info, temp, &dev_info->seg_list, lh) {
+ list_del(&seg_info->lh);
+ segment_unload(seg_info->segment_name);
+ kfree(seg_info);
+ }
kfree(dev_info);
out:
kfree(local_buf);
@@ -473,6 +717,7 @@ static ssize_t
dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
struct dcssblk_dev_info *dev_info;
+ struct segment_info *entry;
int rc, i;
char *local_buf;

@@ -499,26 +744,28 @@ dcssblk_remove_store(struct device *dev,
dev_info = dcssblk_get_device_by_name(local_buf);
if (dev_info == NULL) {
up_write(&dcssblk_devices_sem);
- PRINT_WARN("Segment %s is not loaded!\n", local_buf);
+ PRINT_WARN("Device %s is not loaded!\n", local_buf);
rc = -ENODEV;
goto out_buf;
}
if (atomic_read(&dev_info->use_count) != 0) {
up_write(&dcssblk_devices_sem);
- PRINT_WARN("Segment %s is in use!\n", local_buf);
+ PRINT_WARN("Device %s is in use!\n", local_buf);
rc = -EBUSY;
goto out_buf;
}
- list_del(&dev_info->lh);

+ list_del(&dev_info->lh);
del_gendisk(dev_info->gd);
blk_cleanup_queue(dev_info->dcssblk_queue);
dev_info->gd->queue = NULL;
put_disk(dev_info->gd);
device_unregister(&dev_info->dev);
- segment_unload(dev_info->segment_name);
- PRINT_DEBUG("Segment %s unloaded successfully\n",
- dev_info->segment_name);
+
+ /* unload all related segments */
+ list_for_each_entry(entry, &dev_info->seg_list, lh)
+ segment_unload(entry->segment_name);
+
put_device(&dev_info->dev);
up_write(&dcssblk_devices_sem);

@@ -550,6 +797,7 @@ static int
dcssblk_release(struct inode *inode, struct file *filp)
{
struct dcssblk_dev_info *dev_info;
+ struct segment_info *entry;
int rc;

dev_info = inode->i_bdev->bd_disk->private_data;
@@ -560,9 +808,11 @@ dcssblk_release(struct inode *inode, str
down_write(&dcssblk_devices_sem);
if (atomic_dec_and_test(&dev_info->use_count)
&& (dev_info->save_pending)) {
- PRINT_INFO("Segment %s became idle and is being saved now\n",
+ PRINT_INFO("Device %s became idle and is being saved now\n",
dev_info->segment_name);
- segment_save(dev_info->segment_name);
+ list_for_each_entry(entry, &dev_info->seg_list, lh) {
+ segment_save(entry->segment_name);
+ }
dev_info->save_pending = 0;
}
up_write(&dcssblk_devices_sem);
@@ -602,7 +852,7 @@ dcssblk_make_request(struct request_queu
case SEG_TYPE_SC:
/* cannot write to these segments */
if (bio_data_dir(bio) == WRITE) {
- PRINT_WARN("rejecting write to ro segment %s\n",
+ PRINT_WARN("rejecting write to ro device %s\n",
dev_name(&dev_info->dev));
goto fail;
}
@@ -658,7 +908,7 @@ static void
dcssblk_check_params(void)
{
int rc, i, j, k;
- char buf[9];
+ char buf[DCSSBLK_PARM_LEN + 1];
struct dcssblk_dev_info *dev_info;

for (i = 0; (i < DCSSBLK_PARM_LEN) && (dcssblk_segments[i] != '\0');
@@ -666,15 +916,16 @@ dcssblk_check_params(void)
for (j = i; (dcssblk_segments[j] != ',') &&
(dcssblk_segments[j] != '\0') &&
(dcssblk_segments[j] != '(') &&
- (j - i) < 8; j++)
+ (j < DCSSBLK_PARM_LEN); j++)
{
buf[j-i] = dcssblk_segments[j];
}
buf[j-i] = '\0';
rc = dcssblk_add_store(dcssblk_root_dev, NULL, buf, j-i);
if ((rc >= 0) && (dcssblk_segments[j] == '(')) {
- for (k = 0; buf[k] != '\0'; k++)
+ for (k = 0; (buf[k] != ':') && (buf[k] != '\0'); k++)
buf[k] = toupper(buf[k]);
+ buf[k] = '\0';
if (!strncmp(&dcssblk_segments[j], "(local)", 7)) {
down_read(&dcssblk_devices_sem);
dev_info = dcssblk_get_device_by_name(buf);
@@ -741,10 +992,12 @@ module_exit(dcssblk_exit);

module_param_string(segments, dcssblk_segments, DCSSBLK_PARM_LEN, 0444);
MODULE_PARM_DESC(segments, "Name of DCSS segment(s) to be loaded, "
- "comma-separated list, each name max. 8 chars.\n"
- "Adding \"(local)\" to segment name equals echoing 0 to "
- "/sys/devices/dcssblk/<segment name>/shared after loading "
- "the segment - \n"
- "e.g. segments=\"mydcss1,mydcss2,mydcss3(local)\"");
+ "comma-separated list, names in each set separated "
+ "by commas are separated by colons, each set contains "
+ "names of contiguous segments and each name max. 8 chars.\n"
+ "Adding \"(local)\" to the end of each set equals echoing 0 "
+ "to /sys/devices/dcssblk/<device name>/shared after loading "
+ "the contiguous segments - \n"
+ "e.g. segments=\"mydcss1,mydcss2:mydcss3,mydcss4(local)\"");

MODULE_LICENSE("GPL");

--
blue skies,
Martin.

"Reality continues to ruin my life." - Calvin.

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