On 3/9/22 9:05 PM, Jeff Layton wrote:
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; +
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.cindex 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
