From patchwork Wed Nov 16 10:45:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jingbo Xu X-Patchwork-Id: 13044898 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 283C6C433FE for ; Wed, 16 Nov 2022 10:56:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233425AbiKPK4p (ORCPT ); Wed, 16 Nov 2022 05:56:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36858 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239047AbiKPK4Y (ORCPT ); Wed, 16 Nov 2022 05:56:24 -0500 Received: from out30-131.freemail.mail.aliyun.com (out30-131.freemail.mail.aliyun.com [115.124.30.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E55FC5984C; Wed, 16 Nov 2022 02:45:08 -0800 (PST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R141e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045176;MF=jefflexu@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0VUxfD83_1668595505; Received: from localhost(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0VUxfD83_1668595505) by smtp.aliyun-inc.com; Wed, 16 Nov 2022 18:45:06 +0800 From: Jingbo Xu To: xiang@kernel.org, chao@kernel.org, jlayton@kernel.org, linux-erofs@lists.ozlabs.org, linux-cachefs@redhat.com, dhowells@redhat.com Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v3 1/2] fscache,cachefiles: add prepare_ondemand_read() callback Date: Wed, 16 Nov 2022 18:45:01 +0800 Message-Id: <20221116104502.107431-2-jefflexu@linux.alibaba.com> X-Mailer: git-send-email 2.19.1.6.gb485710b In-Reply-To: <20221116104502.107431-1-jefflexu@linux.alibaba.com> References: <20221116104502.107431-1-jefflexu@linux.alibaba.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add prepare_ondemand_read() callback dedicated for the on-demand read scenario, so that callers from this scenario can be decoupled from netfs_io_subrequest. The original cachefiles_prepare_read() is now refactored to a generic routine accepting a parameter list instead of netfs_io_subrequest. There's no logic change, except that some debug info retrieved from netfs_io_subrequest is removed from trace_cachefiles_prep_read(). Signed-off-by: Jingbo Xu --- fs/cachefiles/io.c | 75 ++++++++++++++++++++----------- include/linux/netfs.h | 7 +++ include/trace/events/cachefiles.h | 27 ++++++----- 3 files changed, 68 insertions(+), 41 deletions(-) diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c index 000a28f46e59..3eeafef21c4e 100644 --- a/fs/cachefiles/io.c +++ b/fs/cachefiles/io.c @@ -385,38 +385,35 @@ static int cachefiles_write(struct netfs_cache_resources *cres, term_func, term_func_priv); } -/* - * Prepare a read operation, shortening it to a cached/uncached - * boundary as appropriate. - */ -static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest *subreq, - loff_t i_size) +static enum netfs_io_source cachefiles_do_prepare_read(struct netfs_cache_resources *cres, + loff_t *_start, size_t *_len, + unsigned long *_flags, loff_t i_size) { enum cachefiles_prepare_read_trace why; - struct netfs_io_request *rreq = subreq->rreq; - struct netfs_cache_resources *cres = &rreq->cache_resources; - struct cachefiles_object *object; + struct cachefiles_object *object = NULL; struct cachefiles_cache *cache; struct fscache_cookie *cookie = fscache_cres_cookie(cres); const struct cred *saved_cred; struct file *file = cachefiles_cres_file(cres); enum netfs_io_source ret = NETFS_DOWNLOAD_FROM_SERVER; + loff_t start = *_start; + size_t len = *_len; loff_t off, to; ino_t ino = file ? file_inode(file)->i_ino : 0; int rc; - _enter("%zx @%llx/%llx", subreq->len, subreq->start, i_size); + _enter("%zx @%llx/%llx", len, start, i_size); - if (subreq->start >= i_size) { + if (start >= i_size) { ret = NETFS_FILL_WITH_ZEROES; why = cachefiles_trace_read_after_eof; goto out_no_object; } if (test_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags)) { - __set_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags); + __set_bit(NETFS_SREQ_COPY_TO_CACHE, _flags); why = cachefiles_trace_read_no_data; - if (!test_bit(NETFS_SREQ_ONDEMAND, &subreq->flags)) + if (!test_bit(NETFS_SREQ_ONDEMAND, _flags)) goto out_no_object; } @@ -437,7 +434,7 @@ static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest * retry: off = cachefiles_inject_read_error(); if (off == 0) - off = vfs_llseek(file, subreq->start, SEEK_DATA); + off = vfs_llseek(file, start, SEEK_DATA); if (off < 0 && off >= (loff_t)-MAX_ERRNO) { if (off == (loff_t)-ENXIO) { why = cachefiles_trace_read_seek_nxio; @@ -449,21 +446,22 @@ static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest * goto out; } - if (off >= subreq->start + subreq->len) { + if (off >= start + len) { why = cachefiles_trace_read_found_hole; goto download_and_store; } - if (off > subreq->start) { + if (off > start) { off = round_up(off, cache->bsize); - subreq->len = off - subreq->start; + len = off - start; + *_len = len; why = cachefiles_trace_read_found_part; goto download_and_store; } to = cachefiles_inject_read_error(); if (to == 0) - to = vfs_llseek(file, subreq->start, SEEK_HOLE); + to = vfs_llseek(file, start, SEEK_HOLE); if (to < 0 && to >= (loff_t)-MAX_ERRNO) { trace_cachefiles_io_error(object, file_inode(file), to, cachefiles_trace_seek_error); @@ -471,12 +469,13 @@ static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest * goto out; } - if (to < subreq->start + subreq->len) { - if (subreq->start + subreq->len >= i_size) + if (to < start + len) { + if (start + len >= i_size) to = round_up(to, cache->bsize); else to = round_down(to, cache->bsize); - subreq->len = to - subreq->start; + len = to - start; + *_len = len; } why = cachefiles_trace_read_have_data; @@ -484,12 +483,11 @@ static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest * goto out; download_and_store: - __set_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags); - if (test_bit(NETFS_SREQ_ONDEMAND, &subreq->flags)) { - rc = cachefiles_ondemand_read(object, subreq->start, - subreq->len); + __set_bit(NETFS_SREQ_COPY_TO_CACHE, _flags); + if (test_bit(NETFS_SREQ_ONDEMAND, _flags)) { + rc = cachefiles_ondemand_read(object, start, len); if (!rc) { - __clear_bit(NETFS_SREQ_ONDEMAND, &subreq->flags); + __clear_bit(NETFS_SREQ_ONDEMAND, _flags); goto retry; } ret = NETFS_INVALID_READ; @@ -497,10 +495,32 @@ static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest * out: cachefiles_end_secure(cache, saved_cred); out_no_object: - trace_cachefiles_prep_read(subreq, ret, why, ino); + trace_cachefiles_prep_read(object, start, len, *_flags, ret, why, ino); return ret; } +/* + * Prepare a read operation, shortening it to a cached/uncached + * boundary as appropriate. + */ +static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest *subreq, + loff_t i_size) +{ + return cachefiles_do_prepare_read(&subreq->rreq->cache_resources, + &subreq->start, &subreq->len, &subreq->flags, i_size); +} + +/* + * Prepare an on-demand read operation, shortening it to a cached/uncached + * boundary as appropriate. + */ +static enum netfs_io_source cachefiles_prepare_ondemand_read(struct netfs_cache_resources *cres, + loff_t start, size_t *_len, loff_t i_size) +{ + unsigned long flags = 1 << NETFS_SREQ_ONDEMAND; + return cachefiles_do_prepare_read(cres, &start, _len, &flags, i_size); +} + /* * Prepare for a write to occur. */ @@ -621,6 +641,7 @@ static const struct netfs_cache_ops cachefiles_netfs_cache_ops = { .write = cachefiles_write, .prepare_read = cachefiles_prepare_read, .prepare_write = cachefiles_prepare_write, + .prepare_ondemand_read = cachefiles_prepare_ondemand_read, .query_occupancy = cachefiles_query_occupancy, }; diff --git a/include/linux/netfs.h b/include/linux/netfs.h index f2402ddeafbf..d82071c37133 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -267,6 +267,13 @@ struct netfs_cache_ops { loff_t *_start, size_t *_len, loff_t i_size, bool no_space_allocated_yet); + /* Prepare an on-demand read operation, shortening it to a cached/uncached + * boundary as appropriate. + */ + enum netfs_io_source (*prepare_ondemand_read)(struct netfs_cache_resources *cres, + loff_t start, size_t *_len, + loff_t i_size); + /* Query the occupancy of the cache in a region, returning where the * next chunk of data starts and how long it is. */ diff --git a/include/trace/events/cachefiles.h b/include/trace/events/cachefiles.h index d8d4d73fe7b6..171c0d7f0bb7 100644 --- a/include/trace/events/cachefiles.h +++ b/include/trace/events/cachefiles.h @@ -428,44 +428,43 @@ TRACE_EVENT(cachefiles_vol_coherency, ); TRACE_EVENT(cachefiles_prep_read, - TP_PROTO(struct netfs_io_subrequest *sreq, + TP_PROTO(struct cachefiles_object *obj, + loff_t start, + size_t len, + unsigned short flags, enum netfs_io_source source, enum cachefiles_prepare_read_trace why, ino_t cache_inode), - TP_ARGS(sreq, source, why, cache_inode), + TP_ARGS(obj, start, len, flags, source, why, cache_inode), TP_STRUCT__entry( - __field(unsigned int, rreq ) - __field(unsigned short, index ) + __field(unsigned int, obj ) __field(unsigned short, flags ) __field(enum netfs_io_source, source ) __field(enum cachefiles_prepare_read_trace, why ) __field(size_t, len ) __field(loff_t, start ) - __field(unsigned int, netfs_inode ) __field(unsigned int, cache_inode ) ), TP_fast_assign( - __entry->rreq = sreq->rreq->debug_id; - __entry->index = sreq->debug_index; - __entry->flags = sreq->flags; + __entry->obj = obj ? obj->debug_id : 0; + __entry->flags = flags; __entry->source = source; __entry->why = why; - __entry->len = sreq->len; - __entry->start = sreq->start; - __entry->netfs_inode = sreq->rreq->inode->i_ino; + __entry->len = len; + __entry->start = start; __entry->cache_inode = cache_inode; ), - TP_printk("R=%08x[%u] %s %s f=%02x s=%llx %zx ni=%x B=%x", - __entry->rreq, __entry->index, + TP_printk("o=%08x %s %s f=%02x s=%llx %zx B=%x", + __entry->obj, __print_symbolic(__entry->source, netfs_sreq_sources), __print_symbolic(__entry->why, cachefiles_prepare_read_traces), __entry->flags, __entry->start, __entry->len, - __entry->netfs_inode, __entry->cache_inode) + __entry->cache_inode) ); TRACE_EVENT(cachefiles_read,