On Wed, 2022-03-09 at 20:25 +0800, xiubli@xxxxxxxxxx wrote:
> From: Xiubo Li <xiubli@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
> ---
>
> 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
--
Jeff Layton <jlayton@xxxxxxxxxx>
