[PATCH] fs: jffs2: Add setup code for spi nor flash.
sourav
sourav.poddar at ti.com
Thu Jan 9 13:57:11 EST 2014
On Thursday 09 January 2014 09:46 PM, Brian Norris wrote:
> On Mon, Dec 09, 2013 at 10:44:35AM +0530, Sourav Poddar wrote:
>> Flash need to be setup, while using it for Jffs2 filesystem.
>> The setup code checks was not present for serial flash like
>> m25p80. As a result of which, internal pointers/buffers are in unknown
>> state. This leads to
>> a. dumps like below[1] while mounting a jffs2 filesystem.
>> b. Hang while doing a mount second time.
>>
>> [1]:
>> root at am437x-evm:~# sync
>> [ 84.112640] INFO: trying to register non-static key.
>> [ 84.117553] the code is fine but needs lockdep annotation.
>> [ 84.122985] turning off the locking correctness validator.
>> [ 84.128417] CPU: 0 PID: 1289 Comm: sync Not tainted 3.12.0-67367-g2d1978c-dirty #18
>> [ 84.136016] [<c001bcb8>] (unwind_backtrace+0x0/0xf0) from [<c0017dd0>] (show_stack+0x10/0x14)
>> [ 84.144439] [<c0017dd0>] (show_stack+0x10/0x14) from [<c05a69c8>] (dump_stack+0x78/0x94)
>> [ 84.152465] [<c05a69c8>] (dump_stack+0x78/0x94) from [<c009e2e0>] (__lock_acquire+0x1788/0x1b8c)
>> [ 84.161132] [<c009e2e0>] (__lock_acquire+0x1788/0x1b8c) from [<c009ec30>] (lock_acquire+0x9c/0x104)
>> [ 84.170104] [<c009ec30>] (lock_acquire+0x9c/0x104) from [<c005ede8>] (flush_work+0x38/0x78)
>> [ 84.178375] [<c005ede8>] (flush_work+0x38/0x78) from [<c005eef0>] (__cancel_work_timer+0x84/0x124)
>> [ 84.187225] [<c005eef0>] (__cancel_work_timer+0x84/0x124) from [<c024c1d4>] (jffs2_sync_fs+0x14/0x38)
>> [ 84.196380] [<c024c1d4>] (jffs2_sync_fs+0x14/0x38) from [<c013c138>] (sync_fs_one_sb+0x28/0x2c)
>> [ 84.204986] [<c013c138>] (sync_fs_one_sb+0x28/0x2c) from [<c0115360>] (iterate_supers+0xb0/0xd8)
>> [ 84.213684] [<c0115360>] (iterate_supers+0xb0/0xd8) from [<c013c228>] (sys_sync+0x3c/0x98)
>> [ 84.221862] [<c013c228>] (sys_sync+0x3c/0x98) from [<c0013dc0>] (ret_fast_syscall+0x0/0x48)
>>
>> The patch fixes the above two issue.
> Are you sure this symptom is caused by the cause you note? It doesn't
> quite seem obvious to me, but I suppose uninitialized buffers/pointers
> can cause a wide range of issues.
Yes, i tried this few times with and w/o this patch and see this. Code
tracing points to this particular area where buffer remain uninitiatised.
>
>> Signed-off-by: Sourav Poddar<sourav.poddar at ti.com>
>> Signed-off-by: George Cherian<george.cherian at ti.com>
>> ---
>> fs/jffs2/fs.c | 7 +++++++
>> fs/jffs2/os-linux.h | 2 ++
>> 2 files changed, 9 insertions(+), 0 deletions(-)
>>
>> diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c
>> index fe3c052..02003f0 100644
>> --- a/fs/jffs2/fs.c
>> +++ b/fs/jffs2/fs.c
>> @@ -725,6 +725,13 @@ static int jffs2_flash_setup(struct jffs2_sb_info *c) {
>> return ret;
>> }
>>
>> + /* m25p80 spi flash */
>> + if (jffs2_nor_spi_wbuf_flash(c)) {
>> + ret = jffs2_nor_wbuf_flash_setup(c);
> If you add this, you need to add the corresponding cleanup
> (jffs2_nor_wbuf_flash_cleanup()) in jffs2_flash_cleanup().
Ok. will do.
>
>> + if (ret)
>> + return ret;
>> + }
>> +
>> /* and an UBI volume */
>> if (jffs2_ubivol(c)) {
>> ret = jffs2_ubivol_setup(c);
>> diff --git a/fs/jffs2/os-linux.h b/fs/jffs2/os-linux.h
>> index d200a9b..09ba999 100644
>> --- a/fs/jffs2/os-linux.h
>> +++ b/fs/jffs2/os-linux.h
>> @@ -134,6 +134,8 @@ int jffs2_ubivol_setup(struct jffs2_sb_info *c);
>> void jffs2_ubivol_cleanup(struct jffs2_sb_info *c);
>>
>> #define jffs2_nor_wbuf_flash(c) (c->mtd->type == MTD_NORFLASH&& ! (c->mtd->flags& MTD_BIT_WRITEABLE))
>> +#define jffs2_nor_spi_wbuf_flash(c) \
>> + (c->mtd->type == MTD_NORFLASH&& (c->mtd->flags& MTD_CAP_NORFLASH))
> How is this check distinct from the existing jffs2_nor_wbuf_flash()
> check? Is m25p80 bit-writeable? IOW, are you sure that the following
> code doesn't alread cover m25p80?
Yes, m25p80 supports CAP_NORFLASH which is WRITEABLE | BIT_WRITEABLE,
while the below Intel code will make the condition false by ! and we spi
flash
setup will not take place. Hence, we need a new #define for spi flash.
> /* and Intel "Sibley" flash */
> if (jffs2_nor_wbuf_flash(c)) {
> ...
>
>> int jffs2_nor_wbuf_flash_setup(struct jffs2_sb_info *c);
>> void jffs2_nor_wbuf_flash_cleanup(struct jffs2_sb_info *c);
>> void jffs2_dirty_trigger(struct jffs2_sb_info *c);
> Brian
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