* [PATCH 1/2] block, dax: move "select DAX" from BLOCK to FS_DAX
@ 2017-05-08 21:03 Dan Williams
2017-05-08 21:03 ` [PATCH 2/2] device-dax: kill NR_DEV_DAX Dan Williams
2017-05-08 22:36 ` [PATCH 1/2] block, dax: move "select DAX" from BLOCK to FS_DAX kbuild test robot
0 siblings, 2 replies; 6+ messages in thread
From: Dan Williams @ 2017-05-08 21:03 UTC (permalink / raw)
To: linux-nvdimm; +Cc: linux-block, Geert Uytterhoeven, linux-kernel
For configurations that do not enable DAX filesystems or drivers, do not
require the DAX core to be built.
The only core block routine that calls a DAX routine is
bdev_dax_supported(), that now fails by default as expected if FS_DAX=n,
or no DAX-capable drivers are configured.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
block/Kconfig | 1 -
fs/Kconfig | 1 +
include/linux/dax.h | 37 ++++++++++++++++++++++++++++++++++---
3 files changed, 35 insertions(+), 4 deletions(-)
diff --git a/block/Kconfig b/block/Kconfig
index 93da7fc3f254..e9f780f815f5 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -6,7 +6,6 @@ menuconfig BLOCK
default y
select SBITMAP
select SRCU
- select DAX
help
Provide block layer support for the kernel.
diff --git a/fs/Kconfig b/fs/Kconfig
index 83eab52fb3f6..b0e42b6a96b9 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -39,6 +39,7 @@ config FS_DAX
depends on MMU
depends on !(ARM || MIPS || SPARC)
select FS_IOMAP
+ select DAX
help
Direct Access (DAX) can be used on memory-backed block devices.
If the block device supports DAX and the filesystem supports DAX,
diff --git a/include/linux/dax.h b/include/linux/dax.h
index d3158e74a59e..e3fa0ad5a12d 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -18,17 +18,48 @@ struct dax_operations {
void **, pfn_t *);
};
+#if IS_ENABLED(CONFIG_DAX)
int dax_read_lock(void);
void dax_read_unlock(int id);
struct dax_device *dax_get_by_host(const char *host);
+void put_dax(struct dax_device *dax_dev);
+long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
+ void **kaddr, pfn_t *pfn);
+#else
+static inline int dax_read_lock(void)
+{
+ /* all dax operations inside this lock will fail below */
+ return 0;
+}
+
+static inline void dax_read_unlock(int id)
+{
+}
+
+static inline struct dax_device *dax_get_by_host(const char *host)
+{
+ return NULL;
+}
+
+static inline void put_dax(struct dax_device *dax_dev)
+{
+}
+
+static inline long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,
+ long nr_pages, void **kaddr, pfn_t *pfn)
+{
+ /* avoid 'uninitialized variable' warnings for @kaddr and @pfn */
+ *pfn = (pfn_t) { .val = ULLONG_MAX };
+ *kaddr = (void *) ULONG_MAX;
+
+ return -EOPNOTSUPP;
+}
+#endif
struct dax_device *alloc_dax(void *private, const char *host,
const struct dax_operations *ops);
-void put_dax(struct dax_device *dax_dev);
bool dax_alive(struct dax_device *dax_dev);
void kill_dax(struct dax_device *dax_dev);
void *dax_get_private(struct dax_device *dax_dev);
-long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
- void **kaddr, pfn_t *pfn);
/*
* We use lowest available bit in exceptional entry for locking, one bit for
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/2] device-dax: kill NR_DEV_DAX
2017-05-08 21:03 [PATCH 1/2] block, dax: move "select DAX" from BLOCK to FS_DAX Dan Williams
@ 2017-05-08 21:03 ` Dan Williams
2017-05-09 14:21 ` Geert Uytterhoeven
2017-05-08 22:36 ` [PATCH 1/2] block, dax: move "select DAX" from BLOCK to FS_DAX kbuild test robot
1 sibling, 1 reply; 6+ messages in thread
From: Dan Williams @ 2017-05-08 21:03 UTC (permalink / raw)
To: linux-nvdimm; +Cc: linux-block, Geert Uytterhoeven, linux-kernel
There is no point to ask how many device-dax instances the kernel should
support. Since we are already using a dynamic major number, just allow
the max number of minors by default and be done. This also fixes the
fact that the proposed max for the NR_DEV_DAX range was larger than what
could be supported by alloc_chrdev_region().
Fixes: ba09c01d2fa8 ("dax: convert to the cdev api")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/dax/Kconfig | 5 -----
drivers/dax/super.c | 11 +++--------
2 files changed, 3 insertions(+), 13 deletions(-)
diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig
index 6b7e20eae16c..b79aa8f7a497 100644
--- a/drivers/dax/Kconfig
+++ b/drivers/dax/Kconfig
@@ -28,9 +28,4 @@ config DEV_DAX_PMEM
Say Y if unsure
-config NR_DEV_DAX
- int "Maximum number of Device-DAX instances"
- default 32768
- range 256 2147483647
-
endif
diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 465dcd7317d5..f2d4f20eb2b8 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -20,10 +20,6 @@
#include <linux/dax.h>
#include <linux/fs.h>
-static int nr_dax = CONFIG_NR_DEV_DAX;
-module_param(nr_dax, int, S_IRUGO);
-MODULE_PARM_DESC(nr_dax, "max number of dax device instances");
-
static dev_t dax_devt;
DEFINE_STATIC_SRCU(dax_srcu);
static struct vfsmount *dax_mnt;
@@ -261,7 +257,7 @@ struct dax_device *alloc_dax(void *private, const char *__host,
if (__host && !host)
return NULL;
- minor = ida_simple_get(&dax_minor_ida, 0, nr_dax, GFP_KERNEL);
+ minor = ida_simple_get(&dax_minor_ida, 0, MINORMASK+1, GFP_KERNEL);
if (minor < 0)
goto err_minor;
@@ -405,8 +401,7 @@ static int __init dax_fs_init(void)
if (rc)
return rc;
- nr_dax = max(nr_dax, 256);
- rc = alloc_chrdev_region(&dax_devt, 0, nr_dax, "dax");
+ rc = alloc_chrdev_region(&dax_devt, 0, MINORMASK+1, "dax");
if (rc)
__dax_fs_exit();
return rc;
@@ -414,7 +409,7 @@ static int __init dax_fs_init(void)
static void __exit dax_fs_exit(void)
{
- unregister_chrdev_region(dax_devt, nr_dax);
+ unregister_chrdev_region(dax_devt, MINORMASK+1);
ida_destroy(&dax_minor_ida);
__dax_fs_exit();
}
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] block, dax: move "select DAX" from BLOCK to FS_DAX
2017-05-08 21:03 [PATCH 1/2] block, dax: move "select DAX" from BLOCK to FS_DAX Dan Williams
2017-05-08 21:03 ` [PATCH 2/2] device-dax: kill NR_DEV_DAX Dan Williams
@ 2017-05-08 22:36 ` kbuild test robot
2017-05-09 7:57 ` Geert Uytterhoeven
1 sibling, 1 reply; 6+ messages in thread
From: kbuild test robot @ 2017-05-08 22:36 UTC (permalink / raw)
To: Dan Williams
Cc: kbuild-all, linux-nvdimm, linux-block, Geert Uytterhoeven, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 1530 bytes --]
Hi Dan,
[auto build test ERROR on linus/master]
[also build test ERROR on next-20170508]
[cannot apply to v4.11]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Dan-Williams/block-dax-move-select-DAX-from-BLOCK-to-FS_DAX/20170509-051522
config: parisc-c3000_defconfig (attached as .config)
compiler: hppa-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=parisc
All errors (new ones prefixed by >>):
fs/built-in.o: In function `bdev_dax_supported':
>> (.text.bdev_dax_supported+0x4c): undefined reference to `dax_get_by_host'
fs/built-in.o: In function `bdev_dax_supported':
>> (.text.bdev_dax_supported+0x5c): undefined reference to `dax_read_lock'
fs/built-in.o: In function `bdev_dax_supported':
>> (.text.bdev_dax_supported+0x7c): undefined reference to `dax_direct_access'
fs/built-in.o: In function `bdev_dax_supported':
>> (.text.bdev_dax_supported+0x88): undefined reference to `dax_read_unlock'
fs/built-in.o: In function `bdev_dax_supported':
>> (.text.bdev_dax_supported+0x90): undefined reference to `put_dax'
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 14644 bytes --]
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] block, dax: move "select DAX" from BLOCK to FS_DAX
2017-05-08 22:36 ` [PATCH 1/2] block, dax: move "select DAX" from BLOCK to FS_DAX kbuild test robot
@ 2017-05-09 7:57 ` Geert Uytterhoeven
2017-05-09 14:11 ` Dan Williams
0 siblings, 1 reply; 6+ messages in thread
From: Geert Uytterhoeven @ 2017-05-09 7:57 UTC (permalink / raw)
To: Dan Williams
Cc: kbuild-all, linux-nvdimm@lists.01.org, linux-block, linux-kernel,
kbuild test robot
Hi Dan,
On Tue, May 9, 2017 at 12:36 AM, kbuild test robot <lkp@intel.com> wrote:
> [auto build test ERROR on linus/master]
> [also build test ERROR on next-20170508]
> [cannot apply to v4.11]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
>
> url: https://github.com/0day-ci/linux/commits/Dan-Williams/block-dax-move-select-DAX-from-BLOCK-to-FS_DAX/20170509-051522
> config: parisc-c3000_defconfig (attached as .config)
> compiler: hppa-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
> reproduce:
> wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # save the attached .config to linux build tree
> make.cross ARCH=parisc
>
> All errors (new ones prefixed by >>):
>
> fs/built-in.o: In function `bdev_dax_supported':
>>> (.text.bdev_dax_supported+0x4c): undefined reference to `dax_get_by_host'
> fs/built-in.o: In function `bdev_dax_supported':
>>> (.text.bdev_dax_supported+0x5c): undefined reference to `dax_read_lock'
> fs/built-in.o: In function `bdev_dax_supported':
>>> (.text.bdev_dax_supported+0x7c): undefined reference to `dax_direct_access'
> fs/built-in.o: In function `bdev_dax_supported':
>>> (.text.bdev_dax_supported+0x88): undefined reference to `dax_read_unlock'
> fs/built-in.o: In function `bdev_dax_supported':
>>> (.text.bdev_dax_supported+0x90): undefined reference to `put_dax'
I ran into the same issue if CONFIG_DAX=m (it's still selected by some other
modular symbol). #if IS_ENABLED(CONFIG_DAX) is true in the modular case, so
the dummies provided by include/linux/dax.h are not used.
However, while changing it to #ifdef CONFIG_DAX allows to build vmlinux, it
leads to other issues as DAX is compiled as a module:
drivers/dax/super.c:35: error: redefinition of ‘dax_read_lock’
include/linux/dax.h:30: error: previous definition of
‘dax_read_lock’ was here
Yes, calling into optional modular code from builtin code in fs/blockdev.c is
tricky ;-( Perhaps you can make bdev_dax_supported() a small wrapper
that calls into the real code through a function pointer, when the DAX module
is available?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] block, dax: move "select DAX" from BLOCK to FS_DAX
2017-05-09 7:57 ` Geert Uytterhoeven
@ 2017-05-09 14:11 ` Dan Williams
0 siblings, 0 replies; 6+ messages in thread
From: Dan Williams @ 2017-05-09 14:11 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: kbuild-all, linux-nvdimm@lists.01.org, linux-block, linux-kernel,
kbuild test robot
On Tue, May 9, 2017 at 12:57 AM, Geert Uytterhoeven
<geert@linux-m68k.org> wrote:
> Hi Dan,
>
> On Tue, May 9, 2017 at 12:36 AM, kbuild test robot <lkp@intel.com> wrote:
>> [auto build test ERROR on linus/master]
>> [also build test ERROR on next-20170508]
>> [cannot apply to v4.11]
>> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
>>
>> url: https://github.com/0day-ci/linux/commits/Dan-Williams/block-dax-move-select-DAX-from-BLOCK-to-FS_DAX/20170509-051522
>> config: parisc-c3000_defconfig (attached as .config)
>> compiler: hppa-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
>> reproduce:
>> wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>> chmod +x ~/bin/make.cross
>> # save the attached .config to linux build tree
>> make.cross ARCH=parisc
>>
>> All errors (new ones prefixed by >>):
>>
>> fs/built-in.o: In function `bdev_dax_supported':
>>>> (.text.bdev_dax_supported+0x4c): undefined reference to `dax_get_by_host'
>> fs/built-in.o: In function `bdev_dax_supported':
>>>> (.text.bdev_dax_supported+0x5c): undefined reference to `dax_read_lock'
>> fs/built-in.o: In function `bdev_dax_supported':
>>>> (.text.bdev_dax_supported+0x7c): undefined reference to `dax_direct_access'
>> fs/built-in.o: In function `bdev_dax_supported':
>>>> (.text.bdev_dax_supported+0x88): undefined reference to `dax_read_unlock'
>> fs/built-in.o: In function `bdev_dax_supported':
>>>> (.text.bdev_dax_supported+0x90): undefined reference to `put_dax'
>
> I ran into the same issue if CONFIG_DAX=m (it's still selected by some other
> modular symbol). #if IS_ENABLED(CONFIG_DAX) is true in the modular case, so
> the dummies provided by include/linux/dax.h are not used.
>
> However, while changing it to #ifdef CONFIG_DAX allows to build vmlinux, it
> leads to other issues as DAX is compiled as a module:
>
> drivers/dax/super.c:35: error: redefinition of ‘dax_read_lock’
> include/linux/dax.h:30: error: previous definition of
> ‘dax_read_lock’ was here
>
> Yes, calling into optional modular code from builtin code in fs/blockdev.c is
> tricky ;-( Perhaps you can make bdev_dax_supported() a small wrapper
> that calls into the real code through a function pointer, when the DAX module
> is available?
In fact, that is close to what I did for v2, and it passed a full run
through the kbuild robot. I'll send it out shortly.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] device-dax: kill NR_DEV_DAX
2017-05-08 21:03 ` [PATCH 2/2] device-dax: kill NR_DEV_DAX Dan Williams
@ 2017-05-09 14:21 ` Geert Uytterhoeven
0 siblings, 0 replies; 6+ messages in thread
From: Geert Uytterhoeven @ 2017-05-09 14:21 UTC (permalink / raw)
To: Dan Williams; +Cc: linux-nvdimm@lists.01.org, linux-block, linux-kernel
On Mon, May 8, 2017 at 11:03 PM, Dan Williams <dan.j.williams@intel.com> wrote:
> There is no point to ask how many device-dax instances the kernel should
> support. Since we are already using a dynamic major number, just allow
> the max number of minors by default and be done. This also fixes the
> fact that the proposed max for the NR_DEV_DAX range was larger than what
> could be supported by alloc_chrdev_region().
>
> Fixes: ba09c01d2fa8 ("dax: convert to the cdev api")
> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-05-09 14:21 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2017-05-08 21:03 [PATCH 1/2] block, dax: move "select DAX" from BLOCK to FS_DAX Dan Williams
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2017-05-09 14:21 ` Geert Uytterhoeven
2017-05-08 22:36 ` [PATCH 1/2] block, dax: move "select DAX" from BLOCK to FS_DAX kbuild test robot
2017-05-09 7:57 ` Geert Uytterhoeven
2017-05-09 14:11 ` Dan Williams
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