* [PATCH] drivers: memory_open cleanup - lookup minor device number from devlist
@ 2009-04-20 4:05 Adriano dos Santos Fernandes
2009-04-21 0:01 ` Andrew Morton
0 siblings, 1 reply; 3+ messages in thread
From: Adriano dos Santos Fernandes @ 2009-04-20 4:05 UTC (permalink / raw)
To: Ingo Molnar, Venkatesh Pallipadi, Suresh Siddha, Arjan van de Ven,
Andrew Morton, linux-kernel
memory_open ignores devlist and does a switch for each item, duplicating
code
and conditional definitions.
Clean it adding backing_dev_info to devlist and use it to lookup for the
minor
device.
Signed-off-by: Adriano dos Santos Fernandes <adrianosf@uol.com.br>
---
drivers/char/mem.c | 115
++++++++++++++++++++-------------------------------
1 files changed, 45 insertions(+), 70 deletions(-)
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 8f05c38..9e350f2 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -861,59 +861,58 @@ static const struct file_operations kmsg_fops = {
.write = kmsg_write,
};
-static int memory_open(struct inode * inode, struct file * filp)
-{
- int ret = 0;
-
- lock_kernel();
- switch (iminor(inode)) {
- case 1:
- filp->f_op = &mem_fops;
- filp->f_mapping->backing_dev_info =
- &directly_mappable_cdev_bdi;
- break;
+static const struct {
+ unsigned int minor;
+ char *name;
+ umode_t mode;
+ const struct file_operations *fops;
+ struct backing_dev_info *dev_info;
+} devlist[] = { /* list of minor devices */
+ {1, "mem", S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops,
+ &directly_mappable_cdev_bdi},
#ifdef CONFIG_DEVKMEM
- case 2:
- filp->f_op = &kmem_fops;
- filp->f_mapping->backing_dev_info =
- &directly_mappable_cdev_bdi;
- break;
+ {2, "kmem", S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops,
+ &directly_mappable_cdev_bdi},
#endif
- case 3:
- filp->f_op = &null_fops;
- break;
+ {3, "null", S_IRUGO | S_IWUGO, &null_fops, NULL},
#ifdef CONFIG_DEVPORT
- case 4:
- filp->f_op = &port_fops;
- break;
+ {4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops, NULL},
#endif
- case 5:
- filp->f_mapping->backing_dev_info = &zero_bdi;
- filp->f_op = &zero_fops;
- break;
- case 7:
- filp->f_op = &full_fops;
- break;
- case 8:
- filp->f_op = &random_fops;
- break;
- case 9:
- filp->f_op = &urandom_fops;
- break;
- case 11:
- filp->f_op = &kmsg_fops;
- break;
+ {5, "zero", S_IRUGO | S_IWUGO, &zero_fops, &zero_bdi},
+ {7, "full", S_IRUGO | S_IWUGO, &full_fops, NULL},
+ {8, "random", S_IRUGO | S_IWUSR, &random_fops, NULL},
+ {9, "urandom", S_IRUGO | S_IWUSR, &urandom_fops, NULL},
+ {11,"kmsg", S_IRUGO | S_IWUSR, &kmsg_fops, NULL},
#ifdef CONFIG_CRASH_DUMP
- case 12:
- filp->f_op = &oldmem_fops;
- break;
+ {12,"oldmem", S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops, NULL},
#endif
- default:
- unlock_kernel();
- return -ENXIO;
+};
+
+static int memory_open(struct inode * inode, struct file * filp)
+{
+ int ret = 0;
+ int i;
+
+ lock_kernel();
+
+ for (i = 0; i < ARRAY_SIZE(devlist); i++) {
+ if (devlist[i].minor == iminor(inode)) {
+ filp->f_op = devlist[i].fops;
+ if (devlist[i].dev_info) {
+ filp->f_mapping->backing_dev_info =
+ devlist[i].dev_info;
+ }
+
+ break;
+ }
}
- if (filp->f_op && filp->f_op->open)
- ret = filp->f_op->open(inode,filp);
+
+ if (i == ARRAY_SIZE(devlist))
+ ret = -ENXIO;
+ else
+ if (filp->f_op && filp->f_op->open)
+ ret = filp->f_op->open(inode,filp);
+
unlock_kernel();
return ret;
}
@@ -922,30 +921,6 @@ static const struct file_operations memory_fops = {
.open = memory_open, /* just a selector for the real open */
};
-static const struct {
- unsigned int minor;
- char *name;
- umode_t mode;
- const struct file_operations *fops;
-} devlist[] = { /* list of minor devices */
- {1, "mem", S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops},
-#ifdef CONFIG_DEVKMEM
- {2, "kmem", S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops},
-#endif
- {3, "null", S_IRUGO | S_IWUGO, &null_fops},
-#ifdef CONFIG_DEVPORT
- {4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops},
-#endif
- {5, "zero", S_IRUGO | S_IWUGO, &zero_fops},
- {7, "full", S_IRUGO | S_IWUGO, &full_fops},
- {8, "random", S_IRUGO | S_IWUSR, &random_fops},
- {9, "urandom", S_IRUGO | S_IWUSR, &urandom_fops},
- {11,"kmsg", S_IRUGO | S_IWUSR, &kmsg_fops},
-#ifdef CONFIG_CRASH_DUMP
- {12,"oldmem", S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops},
-#endif
-};
-
static struct class *mem_class;
static int __init chr_dev_init(void)
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] drivers: memory_open cleanup - lookup minor device number from devlist
2009-04-20 4:05 [PATCH] drivers: memory_open cleanup - lookup minor device number from devlist Adriano dos Santos Fernandes
@ 2009-04-21 0:01 ` Andrew Morton
2009-04-21 0:27 ` Adriano dos Santos Fernandes
0 siblings, 1 reply; 3+ messages in thread
From: Andrew Morton @ 2009-04-21 0:01 UTC (permalink / raw)
To: Adriano dos Santos Fernandes
Cc: mingo, venkatesh.pallipadi, suresh.b.siddha, arjan, linux-kernel
On Mon, 20 Apr 2009 01:05:23 -0300
Adriano dos Santos Fernandes <adrianosf@uol.com.br> wrote:
> memory_open ignores devlist and does a switch for each item, duplicating
> code
> and conditional definitions.
>
> Clean it adding backing_dev_info to devlist and use it to lookup for the
> minor
> device.
The patch looks reasonable, however your email client replaced all tabs
with spaces and I didn't really feel like fixing it all up.
I wonder what the lock_kernel() calls in memory_open() are doing.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] drivers: memory_open cleanup - lookup minor device number from devlist
2009-04-21 0:01 ` Andrew Morton
@ 2009-04-21 0:27 ` Adriano dos Santos Fernandes
0 siblings, 0 replies; 3+ messages in thread
From: Adriano dos Santos Fernandes @ 2009-04-21 0:27 UTC (permalink / raw)
To: Andrew Morton
Cc: mingo, venkatesh.pallipadi, suresh.b.siddha, arjan, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 739 bytes --]
Andrew Morton wrote:
> On Mon, 20 Apr 2009 01:05:23 -0300
> Adriano dos Santos Fernandes <adrianosf@uol.com.br> wrote:
>
>
>> memory_open ignores devlist and does a switch for each item, duplicating
>> code
>> and conditional definitions.
>>
>> Clean it adding backing_dev_info to devlist and use it to lookup for the
>> minor
>> device.
>>
>
> The patch looks reasonable, however your email client replaced all tabs
> with spaces and I didn't really feel like fixing it all up.
>
I'm not having success to let Thunderbird make it right. I put the exact
same patch attached now.
> I wonder what the lock_kernel() calls in memory_open() are doing.
Hmm, not something I can say while submitting my first patch. ;-)
Adriano
[-- Attachment #2: memory_open.patch --]
[-- Type: text/x-patch, Size: 3846 bytes --]
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 8f05c38..9e350f2 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -861,59 +861,58 @@ static const struct file_operations kmsg_fops = {
.write = kmsg_write,
};
-static int memory_open(struct inode * inode, struct file * filp)
-{
- int ret = 0;
-
- lock_kernel();
- switch (iminor(inode)) {
- case 1:
- filp->f_op = &mem_fops;
- filp->f_mapping->backing_dev_info =
- &directly_mappable_cdev_bdi;
- break;
+static const struct {
+ unsigned int minor;
+ char *name;
+ umode_t mode;
+ const struct file_operations *fops;
+ struct backing_dev_info *dev_info;
+} devlist[] = { /* list of minor devices */
+ {1, "mem", S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops,
+ &directly_mappable_cdev_bdi},
#ifdef CONFIG_DEVKMEM
- case 2:
- filp->f_op = &kmem_fops;
- filp->f_mapping->backing_dev_info =
- &directly_mappable_cdev_bdi;
- break;
+ {2, "kmem", S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops,
+ &directly_mappable_cdev_bdi},
#endif
- case 3:
- filp->f_op = &null_fops;
- break;
+ {3, "null", S_IRUGO | S_IWUGO, &null_fops, NULL},
#ifdef CONFIG_DEVPORT
- case 4:
- filp->f_op = &port_fops;
- break;
+ {4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops, NULL},
#endif
- case 5:
- filp->f_mapping->backing_dev_info = &zero_bdi;
- filp->f_op = &zero_fops;
- break;
- case 7:
- filp->f_op = &full_fops;
- break;
- case 8:
- filp->f_op = &random_fops;
- break;
- case 9:
- filp->f_op = &urandom_fops;
- break;
- case 11:
- filp->f_op = &kmsg_fops;
- break;
+ {5, "zero", S_IRUGO | S_IWUGO, &zero_fops, &zero_bdi},
+ {7, "full", S_IRUGO | S_IWUGO, &full_fops, NULL},
+ {8, "random", S_IRUGO | S_IWUSR, &random_fops, NULL},
+ {9, "urandom", S_IRUGO | S_IWUSR, &urandom_fops, NULL},
+ {11,"kmsg", S_IRUGO | S_IWUSR, &kmsg_fops, NULL},
#ifdef CONFIG_CRASH_DUMP
- case 12:
- filp->f_op = &oldmem_fops;
- break;
+ {12,"oldmem", S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops, NULL},
#endif
- default:
- unlock_kernel();
- return -ENXIO;
+};
+
+static int memory_open(struct inode * inode, struct file * filp)
+{
+ int ret = 0;
+ int i;
+
+ lock_kernel();
+
+ for (i = 0; i < ARRAY_SIZE(devlist); i++) {
+ if (devlist[i].minor == iminor(inode)) {
+ filp->f_op = devlist[i].fops;
+ if (devlist[i].dev_info) {
+ filp->f_mapping->backing_dev_info =
+ devlist[i].dev_info;
+ }
+
+ break;
+ }
}
- if (filp->f_op && filp->f_op->open)
- ret = filp->f_op->open(inode,filp);
+
+ if (i == ARRAY_SIZE(devlist))
+ ret = -ENXIO;
+ else
+ if (filp->f_op && filp->f_op->open)
+ ret = filp->f_op->open(inode,filp);
+
unlock_kernel();
return ret;
}
@@ -922,30 +921,6 @@ static const struct file_operations memory_fops = {
.open = memory_open, /* just a selector for the real open */
};
-static const struct {
- unsigned int minor;
- char *name;
- umode_t mode;
- const struct file_operations *fops;
-} devlist[] = { /* list of minor devices */
- {1, "mem", S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops},
-#ifdef CONFIG_DEVKMEM
- {2, "kmem", S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops},
-#endif
- {3, "null", S_IRUGO | S_IWUGO, &null_fops},
-#ifdef CONFIG_DEVPORT
- {4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops},
-#endif
- {5, "zero", S_IRUGO | S_IWUGO, &zero_fops},
- {7, "full", S_IRUGO | S_IWUGO, &full_fops},
- {8, "random", S_IRUGO | S_IWUSR, &random_fops},
- {9, "urandom", S_IRUGO | S_IWUSR, &urandom_fops},
- {11,"kmsg", S_IRUGO | S_IWUSR, &kmsg_fops},
-#ifdef CONFIG_CRASH_DUMP
- {12,"oldmem", S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops},
-#endif
-};
-
static struct class *mem_class;
static int __init chr_dev_init(void)
^ permalink raw reply related [flat|nested] 3+ messages in thread
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2009-04-20 4:05 [PATCH] drivers: memory_open cleanup - lookup minor device number from devlist Adriano dos Santos Fernandes
2009-04-21 0:01 ` Andrew Morton
2009-04-21 0:27 ` Adriano dos Santos Fernandes
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