[Devel] [PATCH 2/2] fs/fuse kio_pcs: check fuse_conn args
Pavel Butsykin
pbutsykin at virtuozzo.com
Thu May 17 14:31:43 MSK 2018
On 17.05.2018 13:05, Kirill Tkhai wrote:
> Hi, Pasha,
>
> On 17.05.2018 12:40, Pavel Butsykin wrote:
>> Allow initialization of kdirect only for vstorage/pstorage.
>>
>> Signed-off-by: Pavel Butsykin <pbutsykin at virtuozzo.com>
>> ---
>> drivers/block/ploop/dev.c | 4 ----
>> fs/fuse/kio/pcs/pcs_fuse_kdirect.c | 23 +++++++++++++++++------
>> include/linux/fs.h | 5 +++++
>> 3 files changed, 22 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c
>> index 0e72656ec8f9..c6094144c7a5 100644
>> --- a/drivers/block/ploop/dev.c
>> +++ b/drivers/block/ploop/dev.c
>> @@ -3880,10 +3880,6 @@ static int ploop_truncate(struct ploop_device * plo, unsigned long arg)
>> return err;
>> }
>>
>> -#define IS_PSTORAGE(sb) (sb->s_magic == FUSE_SUPER_MAGIC && \
>> - (!strcmp(sb->s_subtype, "pstorage") || \
>> - !strcmp(sb->s_subtype, "vstorage")))
>> -
>> static int ploop_bd_full(struct backing_dev_info *bdi, long long nr, int root)
>> {
>> struct ploop_device *plo = bdi->congested_data;
>> diff --git a/fs/fuse/kio/pcs/pcs_fuse_kdirect.c b/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
>> index b8503d55e246..4b9c4a304571 100644
>> --- a/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
>> +++ b/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
>> @@ -144,13 +144,24 @@ void kpcs_conn_abort(struct fuse_conn *fc)
>> }
>>
>> static int kpcs_probe(struct fuse_conn *fc, char *name)
>> -
>> {
>> - printk("%s TODO IMPLEMENT check fuse_conn args here!\n", __FUNCTION__);
>> - if (!strncmp(name, kio_pcs_ops.name, FUSE_KIO_NAME))
>> - return 1;
>> + if (strncmp(name, kio_pcs_ops.name, FUSE_KIO_NAME)) {
>> + printk(KERN_ERR "FUSE: kio_pcs: invalid kio_ops name: %s\n", name);
>
> Despite there was printk() without error level modifier (which is not correct),
> and printk(KERN_ERR) is better, let's follow the modern Linux kernel style,
> which anyway will be requested in case of submitting patches to mainstream.
> pr_err() is more likely to use for such the printing (see the rest of pr_* in printk.h).
>
ok, thanks.
>> + return 0;
>> + }
>>
>> - return 0;
>> + if (!(fc->flags & FUSE_KDIRECT_IO)) {
>> + printk(KERN_ERR "FUSE: kio_pcs: kdirect is not enabled\n");
>> + return 0;
>> + }
>
> I don't think this is needed, since we already check for this bit in fuse_fill_super()
> before call of fuse_kio_get(). But I'm not insist on this.
>
And what is the meaning of this check:
"!strncmp(name, kio_pcs_ops.name, FUSE_KIO_NAME)" ?
We also already have this check. I assumed this can protect against
possible mistakes in the future.
>> +
>> + if (!IS_PSTORAGE(fc->sb)) {
>> + printk(KERN_ERR "FUSE: kio_pcs: kdirect is only available for"
>> + "pstorage/vstorage fuse mount\n");
>> + return 0;
>> + }
>> +
>> + return 1;
>> }
>>
>>
>> @@ -1202,7 +1213,7 @@ err:
>> static struct fuse_kio_ops kio_pcs_ops = {
>> .name = "pcs",
>> .owner = THIS_MODULE,
>> - .probe = kpcs_probe, /*TODO: check sb->dev name */
>> + .probe = kpcs_probe,
>>
>> .conn_init = kpcs_conn_init,
>> .conn_fini = kpcs_conn_fini,
>> diff --git a/include/linux/fs.h b/include/linux/fs.h
>> index a1dc3521f979..21770550b6c1 100644
>> --- a/include/linux/fs.h
>> +++ b/include/linux/fs.h
>> @@ -1713,6 +1713,11 @@ struct super_block {
>> struct list_lru s_inode_lru ____cacheline_aligned_in_smp;
>> };
>>
>> +#define IS_PSTORAGE(sb) ((sb)->s_magic == FUSE_SUPER_MAGIC && \
>> + (sb)->s_subtype && \
>> + (!strcmp((sb)->s_subtype, "pstorage") || \
>> + !strcmp((sb)->s_subtype, "vstorage")))
>> +
>> extern const unsigned super_block_wrapper_version;
>> struct super_block_wrapper {
>> struct super_block sb;
>>
>
> Thanks,
> Kirill
>
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