diff mbox series

[v6] ceph: do not dencrypt the dentry name twice for readdir

Message ID 20220309122556.46503-1-xiubli@redhat.com (mailing list archive)
State New, archived
Headers show
Series [v6] ceph: do not dencrypt the dentry name twice for readdir | expand

Commit Message

Xiubo Li March 9, 2022, 12:25 p.m. UTC 
From: Xiubo Li <xiubli@redhat.com>

For the readdir request the dentries will be pasred and dencrypted
in ceph_readdir_prepopulate(). And in ceph_readdir() we could just
get the dentry name from the dentry cache instead of parsing and
dencrypting them again. This could improve performance.

Signed-off-by: Xiubo Li <xiubli@redhat.com>
---

V6:
- Remove CEPH_ENCRYPTED_LONG_SNAP_NAME_MAX macro and use the NAME_MAX
  instead, since we are limiting the max length of snapshot name to
  240, which is NAME_MAX - 2 * sizeof('_') - sizeof(<inode#>).

V5:
- fix typo of CEPH_ENCRYPTED_LONG_SNAP_NAME_MAX macro
- release the rde->dentry in destroy_reply_info



 fs/ceph/dir.c        | 59 +++++++++++++++++++++-----------------------
 fs/ceph/inode.c      |  7 ++++++
 fs/ceph/mds_client.c |  2 ++
 fs/ceph/mds_client.h |  1 +
 4 files changed, 38 insertions(+), 31 deletions(-)

Comments

Jeff Layton March 9, 2022, 1:05 p.m. UTC | #1 
On Wed, 2022-03-09 at 20:25 +0800, xiubli@redhat.com wrote:
> From: Xiubo Li <xiubli@redhat.com>
> 
> For the readdir request the dentries will be pasred and dencrypted
> in ceph_readdir_prepopulate(). And in ceph_readdir() we could just
> get the dentry name from the dentry cache instead of parsing and
> dencrypting them again. This could improve performance.
> 
> Signed-off-by: Xiubo Li <xiubli@redhat.com>
> ---
> 
> V6:
> - Remove CEPH_ENCRYPTED_LONG_SNAP_NAME_MAX macro and use the NAME_MAX
>   instead, since we are limiting the max length of snapshot name to
>   240, which is NAME_MAX - 2 * sizeof('_') - sizeof(<inode#>).
> 
> V5:
> - fix typo of CEPH_ENCRYPTED_LONG_SNAP_NAME_MAX macro
> - release the rde->dentry in destroy_reply_info
> 
> 
> 
>  fs/ceph/dir.c        | 59 +++++++++++++++++++++-----------------------
>  fs/ceph/inode.c      |  7 ++++++
>  fs/ceph/mds_client.c |  2 ++
>  fs/ceph/mds_client.h |  1 +
>  4 files changed, 38 insertions(+), 31 deletions(-)
> 
> diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
> index 6df2a91af236..19321a1f7399 100644
> --- a/fs/ceph/dir.c
> +++ b/fs/ceph/dir.c
> @@ -316,8 +316,7 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
>  	int err;
>  	unsigned frag = -1;
>  	struct ceph_mds_reply_info_parsed *rinfo;
> -	struct fscrypt_str tname = FSTR_INIT(NULL, 0);
> -	struct fscrypt_str oname = FSTR_INIT(NULL, 0);
> +	char *dentry_name = NULL;
>  
>  	dout("readdir %p file %p pos %llx\n", inode, file, ctx->pos);
>  	if (dfi->file_info.flags & CEPH_F_ATEND)
> @@ -369,14 +368,6 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
>  		spin_unlock(&ci->i_ceph_lock);
>  	}
>  
> -	err = ceph_fname_alloc_buffer(inode, &tname);
> -	if (err < 0)
> -		goto out;
> -
> -	err = ceph_fname_alloc_buffer(inode, &oname);
> -	if (err < 0)
> -		goto out;
> -
>  	/* proceed with a normal readdir */
>  more:
>  	/* do we have the correct frag content buffered? */
> @@ -528,31 +519,39 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
>  			}
>  		}
>  	}
> +
> +	dentry_name = kmalloc(NAME_MAX, GFP_KERNEL);
> +	if (!dentry_name) {
> +		err = -ENOMEM;
> +		ceph_mdsc_put_request(dfi->last_readdir);
> +		dfi->last_readdir = NULL;
> +		goto out;
> +	}
> +
>  	for (; i < rinfo->dir_nr; i++) {
>  		struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;
> -		struct ceph_fname fname = { .dir	= inode,
> -					    .name	= rde->name,
> -					    .name_len	= rde->name_len,
> -					    .ctext	= rde->altname,
> -					    .ctext_len	= rde->altname_len };
> -		u32 olen = oname.len;
> -
> -		err = ceph_fname_to_usr(&fname, &tname, &oname, NULL);
> -		if (err) {
> -			pr_err("%s unable to decode %.*s, got %d\n", __func__,
> -			       rde->name_len, rde->name, err);
> -			goto out;
> -		}
> +		struct dentry *dn = rde->dentry;
> +		int name_len;
>  
>  		BUG_ON(rde->offset < ctx->pos);
>  		BUG_ON(!rde->inode.in);
> +		BUG_ON(!rde->dentry);
>  
>  		ctx->pos = rde->offset;
> -		dout("readdir (%d/%d) -> %llx '%.*s' %p\n",
> -		     i, rinfo->dir_nr, ctx->pos,
> -		     rde->name_len, rde->name, &rde->inode.in);
>  
> -		if (!dir_emit(ctx, oname.name, oname.len,
> +		spin_lock(&dn->d_lock);
> +		memcpy(dentry_name, dn->d_name.name, dn->d_name.len);
> +		name_len = dn->d_name.len;
> +		spin_unlock(&dn->d_lock);
> +
> +		dentry_name[name_len] = '\0';
> +		dout("readdir (%d/%d) -> %llx '%s' %p\n",
> +		     i, rinfo->dir_nr, ctx->pos, dentry_name, &rde->inode.in);
> +
> +		dput(dn);
> +		rde->dentry = NULL;
> +
> +		if (!dir_emit(ctx, dentry_name, name_len,
>  			      ceph_present_ino(inode->i_sb, le64_to_cpu(rde->inode.in->ino)),
>  			      le32_to_cpu(rde->inode.in->mode) >> 12)) {
>  			/*
> @@ -566,8 +565,6 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
>  			goto out;
>  		}
>  
> -		/* Reset the lengths to their original allocated vals */
> -		oname.len = olen;
>  		ctx->pos++;
>  	}
>  
> @@ -625,8 +622,8 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
>  	err = 0;
>  	dout("readdir %p file %p done.\n", inode, file);
>  out:
> -	ceph_fname_free_buffer(inode, &tname);
> -	ceph_fname_free_buffer(inode, &oname);
> +	if (dentry_name)
> +		kfree(dentry_name);
>  	return err;
>  }
>  
> diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
> index b573a0f33450..19e5275eae1c 100644
> --- a/fs/ceph/inode.c
> +++ b/fs/ceph/inode.c
> @@ -1909,6 +1909,7 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req,
>  			goto out;
>  		}
>  
> +		rde->dentry = NULL;
>  		dname.name = oname.name;
>  		dname.len = oname.len;
>  		dname.hash = full_name_hash(parent, dname.name, dname.len);
> @@ -1969,6 +1970,12 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req,
>  			goto retry_lookup;
>  		}
>  
> +		/*
> +		 * ceph_readdir will use the dentry to get the name
> +		 * to avoid doing the dencrypt again there.
> +		 */
> +		rde->dentry = dget(dn);
> +
>  		/* inode */
>  		if (d_really_is_positive(dn)) {
>  			in = d_inode(dn);
> diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
> index 8d704ddd7291..215a52169a1a 100644
> --- a/fs/ceph/mds_client.c
> +++ b/fs/ceph/mds_client.c
> @@ -733,6 +733,8 @@ static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
>  
>  		kfree(rde->inode.fscrypt_auth);
>  		kfree(rde->inode.fscrypt_file);
> +		dput(rde->dentry);
> +		rde->dentry = NULL;
>  	}
>  	free_pages((unsigned long)info->dir_entries, get_order(info->dir_buf_size));
>  }
> diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
> index 0dfe24f94567..663d7754d57d 100644
> --- a/fs/ceph/mds_client.h
> +++ b/fs/ceph/mds_client.h
> @@ -96,6 +96,7 @@ struct ceph_mds_reply_info_in {
>  };
>  
>  struct ceph_mds_reply_dir_entry {
> +	struct dentry		      *dentry;
>  	char                          *name;
>  	u8			      *altname;
>  	u32                           name_len;

Testing this on top of wip-fscrypt, I hit the new BUG_ON you added
immediately with xfstest generic/006. I haven't sat down to work out the
cause though:

[  286.647758] ------------[ cut here ]------------
[  286.652281] kernel BUG at fs/ceph/dir.c:535!
[  286.654487] invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
[  286.656188] CPU: 4 PID: 2073 Comm: find Tainted: G            E     5.17.0-rc6+ #170
[  286.658393] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014
[  286.660775] RIP: 0010:ceph_readdir+0x1271/0x1d90 [ceph]
[  286.662412] Code: 25 c8 48 8b 95 d0 fa ff ff 4d 89 e9 45 89 f0 4c 89 f9 48 c7 c6 00 76 32 c1 48 c7 c7 b0 ec 38 c1 e8 c4 10 6d c8 e9 b8 fb ff ff <0f> 0b 48 89 ea b9 02 00 00 00 48 c1 ea 20 89 d0 31 e8 39 d5 0f 44
[  286.667755] RSP: 0018:ffff8881156ffce0 EFLAGS: 00010246
[  286.669225] RAX: 0000000000000000 RBX: ffff8881648b5e50 RCX: ffffffffc12d25c1
[  286.671209] RDX: dffffc0000000000 RSI: ffffffff8a40007c RDI: ffff8881648b5e50
[  286.673269] RBP: 0000000000000000 R08: ffffffffc12d2523 R09: 0000000000000000
[  286.675577] R10: 0000000000000001 R11: 0000000000000001 R12: ffff8881156ffeb0
[  286.677013] R13: ffff8881156ffeb8 R14: ffff8881648b5e78 R15: 0ff7caa620000002
[  286.678277] FS:  00007fb446008800(0000) GS:ffff88841d400000(0000) knlGS:0000000000000000
[  286.679781] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  286.680800] CR2: 0000564c99ee90e8 CR3: 0000000117e16000 CR4: 00000000003506e0
[  286.682005] Call Trace:
[  286.682472]  <TASK>
[  286.682837]  ? __fdget_pos+0x71/0x80
[  286.683484]  ? __handle_mm_fault+0x17e0/0x1c20
[  286.684245]  ? ceph_d_revalidate+0x7e0/0x7e0 [ceph]
[  286.685265]  ? down_write_killable+0xc7/0x130
[  286.686202]  ? __down_interruptible+0x1d0/0x1d0
[  286.686965]  iterate_dir+0x107/0x2e0
[  286.687584]  __x64_sys_getdents64+0xe2/0x1b0
[  286.688360]  ? filldir+0x270/0x270
[  286.693689]  ? __ia32_sys_getdents+0x1a0/0x1a0
[  286.698465]  ? lockdep_hardirqs_on_prepare+0x129/0x220
[  286.703362]  ? syscall_enter_from_user_mode+0x21/0x70
[  286.708261]  do_syscall_64+0x3b/0x90
[  286.712819]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  286.717584] RIP: 0033:0x7fb44617afd7
[  286.722128] Code: 19 fb ff 4c 89 e0 5b 5d 41 5c c3 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 21 0e 12 00 f7 d8 64 89 02 48
[  286.733041] RSP: 002b:00007ffec9342038 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
[  286.738408] RAX: ffffffffffffffda RBX: 0000564c99e51380 RCX: 00007fb44617afd7
[  286.743834] RDX: 0000000000010000 RSI: 0000564c99e51380 RDI: 0000000000000004
[  286.749041] RBP: 0000564c99e51354 R08: 0000000000000003 R09: 0000000000000001
[  286.754147] R10: 0000000000000fff R11: 0000000000000293 R12: fffffffffffffe98
[  286.759581] R13: 0000000000000000 R14: 0000564c99e51350 R15: 00000000000010fe
[  286.764698]  </TASK>
[  286.769321] Modules linked in: ceph(E) libceph(E) nft_fib_inet(E) nft_fib_ipv4(E) nft_fib_ipv6(E) nft_fib(E) nft_reject_inet(E) nf_reject_ipv4(E) nf_reject_ipv6(E) nft_reject(E) nft_ct(E) nft_chain_nat(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) bridge(E) stp(E) llc(E) ip_set(E) rfkill(E) nf_tables(E) nfnetlink(E) cachefiles(E) fscache(E) netfs(E) sunrpc(E) iTCO_wdt(E) intel_pmc_bxt(E) iTCO_vendor_support(E) intel_rapl_msr(E) joydev(E) i2c_i801(E) virtio_balloon(E) i2c_smbus(E) intel_rapl_common(E) lpc_ich(E) fuse(E) zram(E) ip_tables(E) xfs(E) crct10dif_pclmul(E) crc32_pclmul(E) crc32c_intel(E) ghash_clmulni_intel(E) serio_raw(E) virtio_gpu(E) virtio_dma_buf(E) drm_shmem_helper(E) virtio_console(E) drm_kms_helper(E) virtio_net(E) cec(E) virtio_blk(E) net_failover(E) failover(E) drm(E) qemu_fw_cfg(E)
[  286.811123] ---[ end trace 0000000000000000 ]---
[  286.826446] RIP: 0010:ceph_readdir+0x1271/0x1d90 [ceph]
[  286.858765] Code: 25 c8 48 8b 95 d0 fa ff ff 4d 89 e9 45 89 f0 4c 89 f9 48 c7 c6 00 76 32 c1 48 c7 c7 b0 ec 38 c1 e8 c4 10 6d c8 e9 b8 fb ff ff <0f> 0b 48 89 ea b9 02 00 00 00 48 c1 ea 20 89 d0 31 e8 39 d5 0f 44
[  286.873795] RSP: 0018:ffff8881156ffce0 EFLAGS: 00010246
[  286.888083] RAX: 0000000000000000 RBX: ffff8881648b5e50 RCX: ffffffffc12d25c1
[  286.906391] RDX: dffffc0000000000 RSI: ffffffff8a40007c RDI: ffff8881648b5e50
[  286.922678] RBP: 0000000000000000 R08: ffffffffc12d2523 R09: 0000000000000000
[  286.938922] R10: 0000000000000001 R11: 0000000000000001 R12: ffff8881156ffeb0
[  286.954630] R13: ffff8881156ffeb8 R14: ffff8881648b5e78 R15: 0ff7caa620000002
[  286.970468] FS:  00007fb446008800(0000) GS:ffff88841d400000(0000) knlGS:0000000000000000
[  286.977032] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  286.990098] CR2: 0000564c99ee90e8 CR3: 0000000117e16000 CR4: 00000000003506e0
Xiubo Li March 9, 2022, 1:43 p.m. UTC | #2 
On 3/9/22 9:05 PM, Jeff Layton wrote:
> On Wed, 2022-03-09 at 20:25 +0800, xiubli@redhat.com wrote:
>> From: Xiubo Li <xiubli@redhat.com>
>>
>> For the readdir request the dentries will be pasred and dencrypted
>> in ceph_readdir_prepopulate(). And in ceph_readdir() we could just
>> get the dentry name from the dentry cache instead of parsing and
>> dencrypting them again. This could improve performance.
>>
>> Signed-off-by: Xiubo Li <xiubli@redhat.com>
>> ---
>>
>> V6:
>> - Remove CEPH_ENCRYPTED_LONG_SNAP_NAME_MAX macro and use the NAME_MAX
>>    instead, since we are limiting the max length of snapshot name to
>>    240, which is NAME_MAX - 2 * sizeof('_') - sizeof(<inode#>).
>>
>> V5:
>> - fix typo of CEPH_ENCRYPTED_LONG_SNAP_NAME_MAX macro
>> - release the rde->dentry in destroy_reply_info
>>
>>
>>
>>   fs/ceph/dir.c        | 59 +++++++++++++++++++++-----------------------
>>   fs/ceph/inode.c      |  7 ++++++
>>   fs/ceph/mds_client.c |  2 ++
>>   fs/ceph/mds_client.h |  1 +
>>   4 files changed, 38 insertions(+), 31 deletions(-)
>>
>> diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
>> index 6df2a91af236..19321a1f7399 100644
>> --- a/fs/ceph/dir.c
>> +++ b/fs/ceph/dir.c
>> @@ -316,8 +316,7 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
>>   	int err;
>>   	unsigned frag = -1;
>>   	struct ceph_mds_reply_info_parsed *rinfo;
>> -	struct fscrypt_str tname = FSTR_INIT(NULL, 0);
>> -	struct fscrypt_str oname = FSTR_INIT(NULL, 0);
>> +	char *dentry_name = NULL;
>>   
>>   	dout("readdir %p file %p pos %llx\n", inode, file, ctx->pos);
>>   	if (dfi->file_info.flags & CEPH_F_ATEND)
>> @@ -369,14 +368,6 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
>>   		spin_unlock(&ci->i_ceph_lock);
>>   	}
>>   
>> -	err = ceph_fname_alloc_buffer(inode, &tname);
>> -	if (err < 0)
>> -		goto out;
>> -
>> -	err = ceph_fname_alloc_buffer(inode, &oname);
>> -	if (err < 0)
>> -		goto out;
>> -
>>   	/* proceed with a normal readdir */
>>   more:
>>   	/* do we have the correct frag content buffered? */
>> @@ -528,31 +519,39 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
>>   			}
>>   		}
>>   	}
>> +
>> +	dentry_name = kmalloc(NAME_MAX, GFP_KERNEL);
>> +	if (!dentry_name) {
>> +		err = -ENOMEM;
>> +		ceph_mdsc_put_request(dfi->last_readdir);
>> +		dfi->last_readdir = NULL;
>> +		goto out;
>> +	}
>> +
>>   	for (; i < rinfo->dir_nr; i++) {
>>   		struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;
>> -		struct ceph_fname fname = { .dir	= inode,
>> -					    .name	= rde->name,
>> -					    .name_len	= rde->name_len,
>> -					    .ctext	= rde->altname,
>> -					    .ctext_len	= rde->altname_len };
>> -		u32 olen = oname.len;
>> -
>> -		err = ceph_fname_to_usr(&fname, &tname, &oname, NULL);
>> -		if (err) {
>> -			pr_err("%s unable to decode %.*s, got %d\n", __func__,
>> -			       rde->name_len, rde->name, err);
>> -			goto out;
>> -		}
>> +		struct dentry *dn = rde->dentry;
>> +		int name_len;
>>   
>>   		BUG_ON(rde->offset < ctx->pos);
>>   		BUG_ON(!rde->inode.in);
>> +		BUG_ON(!rde->dentry);
>>   
>>   		ctx->pos = rde->offset;
>> -		dout("readdir (%d/%d) -> %llx '%.*s' %p\n",
>> -		     i, rinfo->dir_nr, ctx->pos,
>> -		     rde->name_len, rde->name, &rde->inode.in);
>>   
>> -		if (!dir_emit(ctx, oname.name, oname.len,
>> +		spin_lock(&dn->d_lock);
>> +		memcpy(dentry_name, dn->d_name.name, dn->d_name.len);
>> +		name_len = dn->d_name.len;
>> +		spin_unlock(&dn->d_lock);
>> +
>> +		dentry_name[name_len] = '\0';
>> +		dout("readdir (%d/%d) -> %llx '%s' %p\n",
>> +		     i, rinfo->dir_nr, ctx->pos, dentry_name, &rde->inode.in);
>> +
>> +		dput(dn);
>> +		rde->dentry = NULL;
>> +

It's buggy here.

In case the the dir_emit() just fails, the rde->dentry has been set to 
NULL, but the file->f_pos won't set to next rde, so when the next 
readdir comes, we will his this bug.

Since will put all the rde->dentry in the 'destroy_reply_info()' when 
releasing the req, so this is not needed.

I will remove the above two line and test it locally.

Thanks.

- XIubo


>> +		if (!dir_emit(ctx, dentry_name, name_len,
>>   			      ceph_present_ino(inode->i_sb, le64_to_cpu(rde->inode.in->ino)),
>>   			      le32_to_cpu(rde->inode.in->mode) >> 12)) {
>>   			/*
>> @@ -566,8 +565,6 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
>>   			goto out;
>>   		}
>>   
>> -		/* Reset the lengths to their original allocated vals */
>> -		oname.len = olen;
>>   		ctx->pos++;
>>   	}
>>   
>> @@ -625,8 +622,8 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
>>   	err = 0;
>>   	dout("readdir %p file %p done.\n", inode, file);
>>   out:
>> -	ceph_fname_free_buffer(inode, &tname);
>> -	ceph_fname_free_buffer(inode, &oname);
>> +	if (dentry_name)
>> +		kfree(dentry_name);
>>   	return err;
>>   }
>>   
>> diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
>> index b573a0f33450..19e5275eae1c 100644
>> --- a/fs/ceph/inode.c
>> +++ b/fs/ceph/inode.c
>> @@ -1909,6 +1909,7 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req,
>>   			goto out;
>>   		}
>>   
>> +		rde->dentry = NULL;
>>   		dname.name = oname.name;
>>   		dname.len = oname.len;
>>   		dname.hash = full_name_hash(parent, dname.name, dname.len);
>> @@ -1969,6 +1970,12 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req,
>>   			goto retry_lookup;
>>   		}
>>   
>> +		/*
>> +		 * ceph_readdir will use the dentry to get the name
>> +		 * to avoid doing the dencrypt again there.
>> +		 */
>> +		rde->dentry = dget(dn);
>> +
>>   		/* inode */
>>   		if (d_really_is_positive(dn)) {
>>   			in = d_inode(dn);
>> diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
>> index 8d704ddd7291..215a52169a1a 100644
>> --- a/fs/ceph/mds_client.c
>> +++ b/fs/ceph/mds_client.c
>> @@ -733,6 +733,8 @@ static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
>>   
>>   		kfree(rde->inode.fscrypt_auth);
>>   		kfree(rde->inode.fscrypt_file);
>> +		dput(rde->dentry);
>> +		rde->dentry = NULL;
>>   	}
>>   	free_pages((unsigned long)info->dir_entries, get_order(info->dir_buf_size));
>>   }
>> diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
>> index 0dfe24f94567..663d7754d57d 100644
>> --- a/fs/ceph/mds_client.h
>> +++ b/fs/ceph/mds_client.h
>> @@ -96,6 +96,7 @@ struct ceph_mds_reply_info_in {
>>   };
>>   
>>   struct ceph_mds_reply_dir_entry {
>> +	struct dentry		      *dentry;
>>   	char                          *name;
>>   	u8			      *altname;
>>   	u32                           name_len;
> Testing this on top of wip-fscrypt, I hit the new BUG_ON you added
> immediately with xfstest generic/006. I haven't sat down to work out the
> cause though:
>
> [  286.647758] ------------[ cut here ]------------
> [  286.652281] kernel BUG at fs/ceph/dir.c:535!
> [  286.654487] invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
> [  286.656188] CPU: 4 PID: 2073 Comm: find Tainted: G            E     5.17.0-rc6+ #170
> [  286.658393] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014
> [  286.660775] RIP: 0010:ceph_readdir+0x1271/0x1d90 [ceph]
> [  286.662412] Code: 25 c8 48 8b 95 d0 fa ff ff 4d 89 e9 45 89 f0 4c 89 f9 48 c7 c6 00 76 32 c1 48 c7 c7 b0 ec 38 c1 e8 c4 10 6d c8 e9 b8 fb ff ff <0f> 0b 48 89 ea b9 02 00 00 00 48 c1 ea 20 89 d0 31 e8 39 d5 0f 44
> [  286.667755] RSP: 0018:ffff8881156ffce0 EFLAGS: 00010246
> [  286.669225] RAX: 0000000000000000 RBX: ffff8881648b5e50 RCX: ffffffffc12d25c1
> [  286.671209] RDX: dffffc0000000000 RSI: ffffffff8a40007c RDI: ffff8881648b5e50
> [  286.673269] RBP: 0000000000000000 R08: ffffffffc12d2523 R09: 0000000000000000
> [  286.675577] R10: 0000000000000001 R11: 0000000000000001 R12: ffff8881156ffeb0
> [  286.677013] R13: ffff8881156ffeb8 R14: ffff8881648b5e78 R15: 0ff7caa620000002
> [  286.678277] FS:  00007fb446008800(0000) GS:ffff88841d400000(0000) knlGS:0000000000000000
> [  286.679781] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [  286.680800] CR2: 0000564c99ee90e8 CR3: 0000000117e16000 CR4: 00000000003506e0
> [  286.682005] Call Trace:
> [  286.682472]  <TASK>
> [  286.682837]  ? __fdget_pos+0x71/0x80
> [  286.683484]  ? __handle_mm_fault+0x17e0/0x1c20
> [  286.684245]  ? ceph_d_revalidate+0x7e0/0x7e0 [ceph]
> [  286.685265]  ? down_write_killable+0xc7/0x130
> [  286.686202]  ? __down_interruptible+0x1d0/0x1d0
> [  286.686965]  iterate_dir+0x107/0x2e0
> [  286.687584]  __x64_sys_getdents64+0xe2/0x1b0
> [  286.688360]  ? filldir+0x270/0x270
> [  286.693689]  ? __ia32_sys_getdents+0x1a0/0x1a0
> [  286.698465]  ? lockdep_hardirqs_on_prepare+0x129/0x220
> [  286.703362]  ? syscall_enter_from_user_mode+0x21/0x70
> [  286.708261]  do_syscall_64+0x3b/0x90
> [  286.712819]  entry_SYSCALL_64_after_hwframe+0x44/0xae
> [  286.717584] RIP: 0033:0x7fb44617afd7
> [  286.722128] Code: 19 fb ff 4c 89 e0 5b 5d 41 5c c3 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 21 0e 12 00 f7 d8 64 89 02 48
> [  286.733041] RSP: 002b:00007ffec9342038 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
> [  286.738408] RAX: ffffffffffffffda RBX: 0000564c99e51380 RCX: 00007fb44617afd7
> [  286.743834] RDX: 0000000000010000 RSI: 0000564c99e51380 RDI: 0000000000000004
> [  286.749041] RBP: 0000564c99e51354 R08: 0000000000000003 R09: 0000000000000001
> [  286.754147] R10: 0000000000000fff R11: 0000000000000293 R12: fffffffffffffe98
> [  286.759581] R13: 0000000000000000 R14: 0000564c99e51350 R15: 00000000000010fe
> [  286.764698]  </TASK>
> [  286.769321] Modules linked in: ceph(E) libceph(E) nft_fib_inet(E) nft_fib_ipv4(E) nft_fib_ipv6(E) nft_fib(E) nft_reject_inet(E) nf_reject_ipv4(E) nf_reject_ipv6(E) nft_reject(E) nft_ct(E) nft_chain_nat(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) bridge(E) stp(E) llc(E) ip_set(E) rfkill(E) nf_tables(E) nfnetlink(E) cachefiles(E) fscache(E) netfs(E) sunrpc(E) iTCO_wdt(E) intel_pmc_bxt(E) iTCO_vendor_support(E) intel_rapl_msr(E) joydev(E) i2c_i801(E) virtio_balloon(E) i2c_smbus(E) intel_rapl_common(E) lpc_ich(E) fuse(E) zram(E) ip_tables(E) xfs(E) crct10dif_pclmul(E) crc32_pclmul(E) crc32c_intel(E) ghash_clmulni_intel(E) serio_raw(E) virtio_gpu(E) virtio_dma_buf(E) drm_shmem_helper(E) virtio_console(E) drm_kms_helper(E) virtio_net(E) cec(E) virtio_blk(E) net_failover(E) failover(E) drm(E) qemu_fw_cfg(E)
> [  286.811123] ---[ end trace 0000000000000000 ]---
> [  286.826446] RIP: 0010:ceph_readdir+0x1271/0x1d90 [ceph]
> [  286.858765] Code: 25 c8 48 8b 95 d0 fa ff ff 4d 89 e9 45 89 f0 4c 89 f9 48 c7 c6 00 76 32 c1 48 c7 c7 b0 ec 38 c1 e8 c4 10 6d c8 e9 b8 fb ff ff <0f> 0b 48 89 ea b9 02 00 00 00 48 c1 ea 20 89 d0 31 e8 39 d5 0f 44
> [  286.873795] RSP: 0018:ffff8881156ffce0 EFLAGS: 00010246
> [  286.888083] RAX: 0000000000000000 RBX: ffff8881648b5e50 RCX: ffffffffc12d25c1
> [  286.906391] RDX: dffffc0000000000 RSI: ffffffff8a40007c RDI: ffff8881648b5e50
> [  286.922678] RBP: 0000000000000000 R08: ffffffffc12d2523 R09: 0000000000000000
> [  286.938922] R10: 0000000000000001 R11: 0000000000000001 R12: ffff8881156ffeb0
> [  286.954630] R13: ffff8881156ffeb8 R14: ffff8881648b5e78 R15: 0ff7caa620000002
> [  286.970468] FS:  00007fb446008800(0000) GS:ffff88841d400000(0000) knlGS:0000000000000000
> [  286.977032] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [  286.990098] CR2: 0000564c99ee90e8 CR3: 0000000117e16000 CR4: 00000000003506e0
>
Xiubo Li March 9, 2022, 1:57 p.m. UTC | #3 
On 3/9/22 9:43 PM, Xiubo Li wrote:
>
> On 3/9/22 9:05 PM, Jeff Layton wrote:
>> On Wed, 2022-03-09 at 20:25 +0800, xiubli@redhat.com wrote:
>>> From: Xiubo Li <xiubli@redhat.com>
>>>
>>> For the readdir request the dentries will be pasred and dencrypted
>>> in ceph_readdir_prepopulate(). And in ceph_readdir() we could just
>>> get the dentry name from the dentry cache instead of parsing and
>>> dencrypting them again. This could improve performance.
>>>
>>> Signed-off-by: Xiubo Li <xiubli@redhat.com>
>>> ---
>>>
>>> V6:
>>> - Remove CEPH_ENCRYPTED_LONG_SNAP_NAME_MAX macro and use the NAME_MAX
>>>    instead, since we are limiting the max length of snapshot name to
>>>    240, which is NAME_MAX - 2 * sizeof('_') - sizeof(<inode#>).
>>>
>>> V5:
>>> - fix typo of CEPH_ENCRYPTED_LONG_SNAP_NAME_MAX macro
>>> - release the rde->dentry in destroy_reply_info
>>>
>>>
>>>
>>>   fs/ceph/dir.c        | 59 
>>> +++++++++++++++++++++-----------------------
>>>   fs/ceph/inode.c      |  7 ++++++
>>>   fs/ceph/mds_client.c |  2 ++
>>>   fs/ceph/mds_client.h |  1 +
>>>   4 files changed, 38 insertions(+), 31 deletions(-)
>>>
>>> diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
>>> index 6df2a91af236..19321a1f7399 100644
>>> --- a/fs/ceph/dir.c
>>> +++ b/fs/ceph/dir.c
>>> @@ -316,8 +316,7 @@ static int ceph_readdir(struct file *file, 
>>> struct dir_context *ctx)
>>>       int err;
>>>       unsigned frag = -1;
>>>       struct ceph_mds_reply_info_parsed *rinfo;
>>> -    struct fscrypt_str tname = FSTR_INIT(NULL, 0);
>>> -    struct fscrypt_str oname = FSTR_INIT(NULL, 0);
>>> +    char *dentry_name = NULL;
>>>         dout("readdir %p file %p pos %llx\n", inode, file, ctx->pos);
>>>       if (dfi->file_info.flags & CEPH_F_ATEND)
>>> @@ -369,14 +368,6 @@ static int ceph_readdir(struct file *file, 
>>> struct dir_context *ctx)
>>>           spin_unlock(&ci->i_ceph_lock);
>>>       }
>>>   -    err = ceph_fname_alloc_buffer(inode, &tname);
>>> -    if (err < 0)
>>> -        goto out;
>>> -
>>> -    err = ceph_fname_alloc_buffer(inode, &oname);
>>> -    if (err < 0)
>>> -        goto out;
>>> -
>>>       /* proceed with a normal readdir */
>>>   more:
>>>       /* do we have the correct frag content buffered? */
>>> @@ -528,31 +519,39 @@ static int ceph_readdir(struct file *file, 
>>> struct dir_context *ctx)
>>>               }
>>>           }
>>>       }
>>> +
>>> +    dentry_name = kmalloc(NAME_MAX, GFP_KERNEL);
>>> +    if (!dentry_name) {
>>> +        err = -ENOMEM;
>>> +        ceph_mdsc_put_request(dfi->last_readdir);
>>> +        dfi->last_readdir = NULL;
>>> +        goto out;
>>> +    }
>>> +
>>>       for (; i < rinfo->dir_nr; i++) {
>>>           struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries 
>>> + i;
>>> -        struct ceph_fname fname = { .dir    = inode,
>>> -                        .name    = rde->name,
>>> -                        .name_len    = rde->name_len,
>>> -                        .ctext    = rde->altname,
>>> -                        .ctext_len    = rde->altname_len };
>>> -        u32 olen = oname.len;
>>> -
>>> -        err = ceph_fname_to_usr(&fname, &tname, &oname, NULL);
>>> -        if (err) {
>>> -            pr_err("%s unable to decode %.*s, got %d\n", __func__,
>>> -                   rde->name_len, rde->name, err);
>>> -            goto out;
>>> -        }
>>> +        struct dentry *dn = rde->dentry;
>>> +        int name_len;
>>>             BUG_ON(rde->offset < ctx->pos);
>>>           BUG_ON(!rde->inode.in);
>>> +        BUG_ON(!rde->dentry);
>>>             ctx->pos = rde->offset;
>>> -        dout("readdir (%d/%d) -> %llx '%.*s' %p\n",
>>> -             i, rinfo->dir_nr, ctx->pos,
>>> -             rde->name_len, rde->name, &rde->inode.in);
>>>   -        if (!dir_emit(ctx, oname.name, oname.len,
>>> +        spin_lock(&dn->d_lock);
>>> +        memcpy(dentry_name, dn->d_name.name, dn->d_name.len);
>>> +        name_len = dn->d_name.len;
>>> +        spin_unlock(&dn->d_lock);
>>> +
>>> +        dentry_name[name_len] = '\0';
>>> +        dout("readdir (%d/%d) -> %llx '%s' %p\n",
>>> +             i, rinfo->dir_nr, ctx->pos, dentry_name, &rde->inode.in);
>>> +
>>> +        dput(dn);
>>> +        rde->dentry = NULL;
>>> +
>
> It's buggy here.
>
> In case the the dir_emit() just fails, the rde->dentry has been set to 
> NULL, but the file->f_pos won't set to next rde, so when the next 
> readdir comes, we will his this bug.
>
> Since will put all the rde->dentry in the 'destroy_reply_info()' when 
> releasing the req, so this is not needed.
>
> I will remove the above two line and test it locally.
>
The relevant logs:


266272 <7>[10027.239390] ceph:  filldir stopping us...
266273 <7>[10027.240437] ceph:  readdir 00000000fae918a2 file 
000000008c9cfe7f pos ff7f38e60000002
266274 <7>[10027.240448] ceph:  readdir frag 0 num 1024 pos 
ff7f38e60000002 chunk first ff4001b50000002
266275 <7>[10027.240493] ceph:  readdir (1022/1024) -> ff7f38e60000002 
'adcaba' 000000009240ec06

After this the xfstest passed and also the fsstress test.

xfstest for generic/006:

[root@lxbceph1 xfstests]# ./check generic/006
FSTYP         -- ceph
PLATFORM      -- Linux/x86_64 lxbceph1 5.17.0-rc6+
MKFS_OPTIONS  -- 10.72.47.117:40437:/testB
MOUNT_OPTIONS -- -o 
test_dummy_encryption,name=admin,nowsync,copyfrom,rasize=4096 -o 
context=system_u:object_r:root_t:s0 10.72.47.117:40437:/testB /mnt/kcephfs.B

generic/006 49s ... 22s
Ran: generic/006
Passed all 1 tests

[root@lxbceph1 xfstests]# ./check generic/006
FSTYP         -- ceph
PLATFORM      -- Linux/x86_64 lxbceph1 5.17.0-rc6+
MKFS_OPTIONS  -- 10.72.47.117:40437:/testB
MOUNT_OPTIONS -- -o 
test_dummy_encryption,name=admin,nowsync,copyfrom,rasize=4096 -o 
context=system_u:object_r:root_t:s0 10.72.47.117:40437:/testB /mnt/kcephfs.B

generic/006 22s ... 27s
Ran: generic/006
Passed all 1 tests


fsstress test:

2/994: dread - d5/d15/d58/deb/f131 zero size
2/995: creat d5/d15/d4e/f144 x:0 0 0
2/996: symlink d5/d15/d2d/d63/dbd/l145 0
2/997: unlink d5/d15/d2d/da2/db8/d1b/l4d 0
2/998: dwrite d5/d15/f3b [4194304,4194304] 0
2/999: readlink d5/d15/d2d/da2/db8/d21/dc7/d133/l108 0
+ rm -rf -- ./tmp.PBIQVJ10zf

I will send the V7.

Thanks

- Xiubo


> Thanks.
>
> - XIubo
>
>
>>> +        if (!dir_emit(ctx, dentry_name, name_len,
>>>                     ceph_present_ino(inode->i_sb, 
>>> le64_to_cpu(rde->inode.in->ino)),
>>>                     le32_to_cpu(rde->inode.in->mode) >> 12)) {
>>>               /*
>>> @@ -566,8 +565,6 @@ static int ceph_readdir(struct file *file, 
>>> struct dir_context *ctx)
>>>               goto out;
>>>           }
>>>   -        /* Reset the lengths to their original allocated vals */
>>> -        oname.len = olen;
>>>           ctx->pos++;
>>>       }
>>>   @@ -625,8 +622,8 @@ static int ceph_readdir(struct file *file, 
>>> struct dir_context *ctx)
>>>       err = 0;
>>>       dout("readdir %p file %p done.\n", inode, file);
>>>   out:
>>> -    ceph_fname_free_buffer(inode, &tname);
>>> -    ceph_fname_free_buffer(inode, &oname);
>>> +    if (dentry_name)
>>> +        kfree(dentry_name);
>>>       return err;
>>>   }
>>>   diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
>>> index b573a0f33450..19e5275eae1c 100644
>>> --- a/fs/ceph/inode.c
>>> +++ b/fs/ceph/inode.c
>>> @@ -1909,6 +1909,7 @@ int ceph_readdir_prepopulate(struct 
>>> ceph_mds_request *req,
>>>               goto out;
>>>           }
>>>   +        rde->dentry = NULL;
>>>           dname.name = oname.name;
>>>           dname.len = oname.len;
>>>           dname.hash = full_name_hash(parent, dname.name, dname.len);
>>> @@ -1969,6 +1970,12 @@ int ceph_readdir_prepopulate(struct 
>>> ceph_mds_request *req,
>>>               goto retry_lookup;
>>>           }
>>>   +        /*
>>> +         * ceph_readdir will use the dentry to get the name
>>> +         * to avoid doing the dencrypt again there.
>>> +         */
>>> +        rde->dentry = dget(dn);
>>> +
>>>           /* inode */
>>>           if (d_really_is_positive(dn)) {
>>>               in = d_inode(dn);
>>> diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
>>> index 8d704ddd7291..215a52169a1a 100644
>>> --- a/fs/ceph/mds_client.c
>>> +++ b/fs/ceph/mds_client.c
>>> @@ -733,6 +733,8 @@ static void destroy_reply_info(struct 
>>> ceph_mds_reply_info_parsed *info)
>>>             kfree(rde->inode.fscrypt_auth);
>>>           kfree(rde->inode.fscrypt_file);
>>> +        dput(rde->dentry);
>>> +        rde->dentry = NULL;
>>>       }
>>>       free_pages((unsigned long)info->dir_entries, 
>>> get_order(info->dir_buf_size));
>>>   }
>>> diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
>>> index 0dfe24f94567..663d7754d57d 100644
>>> --- a/fs/ceph/mds_client.h
>>> +++ b/fs/ceph/mds_client.h
>>> @@ -96,6 +96,7 @@ struct ceph_mds_reply_info_in {
>>>   };
>>>     struct ceph_mds_reply_dir_entry {
>>> +    struct dentry              *dentry;
>>>       char                          *name;
>>>       u8                  *altname;
>>>       u32                           name_len;
>> Testing this on top of wip-fscrypt, I hit the new BUG_ON you added
>> immediately with xfstest generic/006. I haven't sat down to work out the
>> cause though:
>>
>> [  286.647758] ------------[ cut here ]------------
>> [  286.652281] kernel BUG at fs/ceph/dir.c:535!
>> [  286.654487] invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
>> [  286.656188] CPU: 4 PID: 2073 Comm: find Tainted: G E     
>> 5.17.0-rc6+ #170
>> [  286.658393] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), 
>> BIOS 1.15.0-1.fc35 04/01/2014
>> [  286.660775] RIP: 0010:ceph_readdir+0x1271/0x1d90 [ceph]
>> [  286.662412] Code: 25 c8 48 8b 95 d0 fa ff ff 4d 89 e9 45 89 f0 4c 
>> 89 f9 48 c7 c6 00 76 32 c1 48 c7 c7 b0 ec 38 c1 e8 c4 10 6d c8 e9 b8 
>> fb ff ff <0f> 0b 48 89 ea b9 02 00 00 00 48 c1 ea 20 89 d0 31 e8 39 
>> d5 0f 44
>> [  286.667755] RSP: 0018:ffff8881156ffce0 EFLAGS: 00010246
>> [  286.669225] RAX: 0000000000000000 RBX: ffff8881648b5e50 RCX: 
>> ffffffffc12d25c1
>> [  286.671209] RDX: dffffc0000000000 RSI: ffffffff8a40007c RDI: 
>> ffff8881648b5e50
>> [  286.673269] RBP: 0000000000000000 R08: ffffffffc12d2523 R09: 
>> 0000000000000000
>> [  286.675577] R10: 0000000000000001 R11: 0000000000000001 R12: 
>> ffff8881156ffeb0
>> [  286.677013] R13: ffff8881156ffeb8 R14: ffff8881648b5e78 R15: 
>> 0ff7caa620000002
>> [  286.678277] FS:  00007fb446008800(0000) GS:ffff88841d400000(0000) 
>> knlGS:0000000000000000
>> [  286.679781] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [  286.680800] CR2: 0000564c99ee90e8 CR3: 0000000117e16000 CR4: 
>> 00000000003506e0
>> [  286.682005] Call Trace:
>> [  286.682472]  <TASK>
>> [  286.682837]  ? __fdget_pos+0x71/0x80
>> [  286.683484]  ? __handle_mm_fault+0x17e0/0x1c20
>> [  286.684245]  ? ceph_d_revalidate+0x7e0/0x7e0 [ceph]
>> [  286.685265]  ? down_write_killable+0xc7/0x130
>> [  286.686202]  ? __down_interruptible+0x1d0/0x1d0
>> [  286.686965]  iterate_dir+0x107/0x2e0
>> [  286.687584]  __x64_sys_getdents64+0xe2/0x1b0
>> [  286.688360]  ? filldir+0x270/0x270
>> [  286.693689]  ? __ia32_sys_getdents+0x1a0/0x1a0
>> [  286.698465]  ? lockdep_hardirqs_on_prepare+0x129/0x220
>> [  286.703362]  ? syscall_enter_from_user_mode+0x21/0x70
>> [  286.708261]  do_syscall_64+0x3b/0x90
>> [  286.712819]  entry_SYSCALL_64_after_hwframe+0x44/0xae
>> [  286.717584] RIP: 0033:0x7fb44617afd7
>> [  286.722128] Code: 19 fb ff 4c 89 e0 5b 5d 41 5c c3 0f 1f 84 00 00 
>> 00 00 00 f3 0f 1e fa b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 
>> 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 21 0e 12 00 f7 d8 64 
>> 89 02 48
>> [  286.733041] RSP: 002b:00007ffec9342038 EFLAGS: 00000293 ORIG_RAX: 
>> 00000000000000d9
>> [  286.738408] RAX: ffffffffffffffda RBX: 0000564c99e51380 RCX: 
>> 00007fb44617afd7
>> [  286.743834] RDX: 0000000000010000 RSI: 0000564c99e51380 RDI: 
>> 0000000000000004
>> [  286.749041] RBP: 0000564c99e51354 R08: 0000000000000003 R09: 
>> 0000000000000001
>> [  286.754147] R10: 0000000000000fff R11: 0000000000000293 R12: 
>> fffffffffffffe98
>> [  286.759581] R13: 0000000000000000 R14: 0000564c99e51350 R15: 
>> 00000000000010fe
>> [  286.764698]  </TASK>
>> [  286.769321] Modules linked in: ceph(E) libceph(E) nft_fib_inet(E) 
>> nft_fib_ipv4(E) nft_fib_ipv6(E) nft_fib(E) nft_reject_inet(E) 
>> nf_reject_ipv4(E) nf_reject_ipv6(E) nft_reject(E) nft_ct(E) 
>> nft_chain_nat(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) 
>> nf_defrag_ipv4(E) bridge(E) stp(E) llc(E) ip_set(E) rfkill(E) 
>> nf_tables(E) nfnetlink(E) cachefiles(E) fscache(E) netfs(E) sunrpc(E) 
>> iTCO_wdt(E) intel_pmc_bxt(E) iTCO_vendor_support(E) intel_rapl_msr(E) 
>> joydev(E) i2c_i801(E) virtio_balloon(E) i2c_smbus(E) 
>> intel_rapl_common(E) lpc_ich(E) fuse(E) zram(E) ip_tables(E) xfs(E) 
>> crct10dif_pclmul(E) crc32_pclmul(E) crc32c_intel(E) 
>> ghash_clmulni_intel(E) serio_raw(E) virtio_gpu(E) virtio_dma_buf(E) 
>> drm_shmem_helper(E) virtio_console(E) drm_kms_helper(E) virtio_net(E) 
>> cec(E) virtio_blk(E) net_failover(E) failover(E) drm(E) qemu_fw_cfg(E)
>> [  286.811123] ---[ end trace 0000000000000000 ]---
>> [  286.826446] RIP: 0010:ceph_readdir+0x1271/0x1d90 [ceph]
>> [  286.858765] Code: 25 c8 48 8b 95 d0 fa ff ff 4d 89 e9 45 89 f0 4c 
>> 89 f9 48 c7 c6 00 76 32 c1 48 c7 c7 b0 ec 38 c1 e8 c4 10 6d c8 e9 b8 
>> fb ff ff <0f> 0b 48 89 ea b9 02 00 00 00 48 c1 ea 20 89 d0 31 e8 39 
>> d5 0f 44
>> [  286.873795] RSP: 0018:ffff8881156ffce0 EFLAGS: 00010246
>> [  286.888083] RAX: 0000000000000000 RBX: ffff8881648b5e50 RCX: 
>> ffffffffc12d25c1
>> [  286.906391] RDX: dffffc0000000000 RSI: ffffffff8a40007c RDI: 
>> ffff8881648b5e50
>> [  286.922678] RBP: 0000000000000000 R08: ffffffffc12d2523 R09: 
>> 0000000000000000
>> [  286.938922] R10: 0000000000000001 R11: 0000000000000001 R12: 
>> ffff8881156ffeb0
>> [  286.954630] R13: ffff8881156ffeb8 R14: ffff8881648b5e78 R15: 
>> 0ff7caa620000002
>> [  286.970468] FS:  00007fb446008800(0000) GS:ffff88841d400000(0000) 
>> knlGS:0000000000000000
>> [  286.977032] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [  286.990098] CR2: 0000564c99ee90e8 CR3: 0000000117e16000 CR4: 
>> 00000000003506e0
>>
diff mbox series

Patch

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 6df2a91af236..19321a1f7399 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -316,8 +316,7 @@  static int ceph_readdir(struct file *file, struct dir_context *ctx)
 	int err;
 	unsigned frag = -1;
 	struct ceph_mds_reply_info_parsed *rinfo;
-	struct fscrypt_str tname = FSTR_INIT(NULL, 0);
-	struct fscrypt_str oname = FSTR_INIT(NULL, 0);
+	char *dentry_name = NULL;
 
 	dout("readdir %p file %p pos %llx\n", inode, file, ctx->pos);
 	if (dfi->file_info.flags & CEPH_F_ATEND)
@@ -369,14 +368,6 @@  static int ceph_readdir(struct file *file, struct dir_context *ctx)
 		spin_unlock(&ci->i_ceph_lock);
 	}
 
-	err = ceph_fname_alloc_buffer(inode, &tname);
-	if (err < 0)
-		goto out;
-
-	err = ceph_fname_alloc_buffer(inode, &oname);
-	if (err < 0)
-		goto out;
-
 	/* proceed with a normal readdir */
 more:
 	/* do we have the correct frag content buffered? */
@@ -528,31 +519,39 @@  static int ceph_readdir(struct file *file, struct dir_context *ctx)
 			}
 		}
 	}
+
+	dentry_name = kmalloc(NAME_MAX, GFP_KERNEL);
+	if (!dentry_name) {
+		err = -ENOMEM;
+		ceph_mdsc_put_request(dfi->last_readdir);
+		dfi->last_readdir = NULL;
+		goto out;
+	}
+
 	for (; i < rinfo->dir_nr; i++) {
 		struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;
-		struct ceph_fname fname = { .dir	= inode,
-					    .name	= rde->name,
-					    .name_len	= rde->name_len,
-					    .ctext	= rde->altname,
-					    .ctext_len	= rde->altname_len };
-		u32 olen = oname.len;
-
-		err = ceph_fname_to_usr(&fname, &tname, &oname, NULL);
-		if (err) {
-			pr_err("%s unable to decode %.*s, got %d\n", __func__,
-			       rde->name_len, rde->name, err);
-			goto out;
-		}
+		struct dentry *dn = rde->dentry;
+		int name_len;
 
 		BUG_ON(rde->offset < ctx->pos);
 		BUG_ON(!rde->inode.in);
+		BUG_ON(!rde->dentry);
 
 		ctx->pos = rde->offset;
-		dout("readdir (%d/%d) -> %llx '%.*s' %p\n",
-		     i, rinfo->dir_nr, ctx->pos,
-		     rde->name_len, rde->name, &rde->inode.in);
 
-		if (!dir_emit(ctx, oname.name, oname.len,
+		spin_lock(&dn->d_lock);
+		memcpy(dentry_name, dn->d_name.name, dn->d_name.len);
+		name_len = dn->d_name.len;
+		spin_unlock(&dn->d_lock);
+
+		dentry_name[name_len] = '\0';
+		dout("readdir (%d/%d) -> %llx '%s' %p\n",
+		     i, rinfo->dir_nr, ctx->pos, dentry_name, &rde->inode.in);
+
+		dput(dn);
+		rde->dentry = NULL;
+
+		if (!dir_emit(ctx, dentry_name, name_len,
 			      ceph_present_ino(inode->i_sb, le64_to_cpu(rde->inode.in->ino)),
 			      le32_to_cpu(rde->inode.in->mode) >> 12)) {
 			/*
@@ -566,8 +565,6 @@  static int ceph_readdir(struct file *file, struct dir_context *ctx)
 			goto out;
 		}
 
-		/* Reset the lengths to their original allocated vals */
-		oname.len = olen;
 		ctx->pos++;
 	}
 
@@ -625,8 +622,8 @@  static int ceph_readdir(struct file *file, struct dir_context *ctx)
 	err = 0;
 	dout("readdir %p file %p done.\n", inode, file);
 out:
-	ceph_fname_free_buffer(inode, &tname);
-	ceph_fname_free_buffer(inode, &oname);
+	if (dentry_name)
+		kfree(dentry_name);
 	return err;
 }
 
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index b573a0f33450..19e5275eae1c 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1909,6 +1909,7 @@  int ceph_readdir_prepopulate(struct ceph_mds_request *req,
 			goto out;
 		}
 
+		rde->dentry = NULL;
 		dname.name = oname.name;
 		dname.len = oname.len;
 		dname.hash = full_name_hash(parent, dname.name, dname.len);
@@ -1969,6 +1970,12 @@  int ceph_readdir_prepopulate(struct ceph_mds_request *req,
 			goto retry_lookup;
 		}
 
+		/*
+		 * ceph_readdir will use the dentry to get the name
+		 * to avoid doing the dencrypt again there.
+		 */
+		rde->dentry = dget(dn);
+
 		/* inode */
 		if (d_really_is_positive(dn)) {
 			in = d_inode(dn);
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 8d704ddd7291..215a52169a1a 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -733,6 +733,8 @@  static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 
 		kfree(rde->inode.fscrypt_auth);
 		kfree(rde->inode.fscrypt_file);
+		dput(rde->dentry);
+		rde->dentry = NULL;
 	}
 	free_pages((unsigned long)info->dir_entries, get_order(info->dir_buf_size));
 }
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index 0dfe24f94567..663d7754d57d 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -96,6 +96,7 @@  struct ceph_mds_reply_info_in {
 };
 
 struct ceph_mds_reply_dir_entry {
+	struct dentry		      *dentry;
 	char                          *name;
 	u8			      *altname;
 	u32                           name_len;