From ec1bd37123c607ca6485beb4542a792a4db765aa Mon Sep 17 00:00:00 2001 From: Khalid Masum Date: Thu, 18 Aug 2022 10:07:38 +0600 Subject: [PATCH 1/3] fscache: fix misdocumented parameter This patch fixes two warnings generated by make docs. The functions fscache_use_cookie and fscache_unuse_cookie, both have a parameter named cookie. But they are documented with the name "object" with unclear description. Which generates the warning when creating docs. This commit will replace the currently misdocumented parameter names with the correct ones while adding proper descriptions. CC: Randy Dunlap Signed-off-by: Khalid Masum Signed-off-by: David Howells Link: https://lore.kernel.org/r/20220521142446.4746-1-khalid.masum.92@gmail.com/ # v1 Link: https://lore.kernel.org/r/20220818040738.12036-1-khalid.masum.92@gmail.com/ # v2 Link: https://lore.kernel.org/r/880d7d25753fb326ee17ac08005952112fcf9bdb.1657360984.git.mchehab@kernel.org/ # Mauro's version --- include/linux/fscache.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/fscache.h b/include/linux/fscache.h index 720874e6ee947..36e5dd84cf599 100644 --- a/include/linux/fscache.h +++ b/include/linux/fscache.h @@ -258,7 +258,7 @@ struct fscache_cookie *fscache_acquire_cookie(struct fscache_volume *volume, /** * fscache_use_cookie - Request usage of cookie attached to an object - * @object: Object description + * @cookie: The cookie representing the cache object * @will_modify: If cache is expected to be modified locally * * Request usage of the cookie attached to an object. The caller should tell @@ -274,7 +274,7 @@ static inline void fscache_use_cookie(struct fscache_cookie *cookie, /** * fscache_unuse_cookie - Cease usage of cookie attached to an object - * @object: Object description + * @cookie: The cookie representing the cache object * @aux_data: Updated auxiliary data (or NULL) * @object_size: Revised size of the object (or NULL) * From c93ccd63b18c8d108c57b2bb0e5f3b058b9d2029 Mon Sep 17 00:00:00 2001 From: Sun Ke Date: Fri, 26 Aug 2022 10:35:15 +0800 Subject: [PATCH 2/3] cachefiles: fix error return code in cachefiles_ondemand_copen() The cache_size field of copen is specified by the user daemon. If cache_size < 0, then the OPEN request is expected to fail, while copen itself shall succeed. However, returning 0 is indeed unexpected when cache_size is an invalid error code. Fix this by returning error when cache_size is an invalid error code. Changes ======= v4: update the code suggested by Dan v3: update the commit log suggested by Jingbo. Fixes: c8383054506c ("cachefiles: notify the user daemon when looking up cookie") Signed-off-by: Sun Ke Suggested-by: Jeffle Xu Suggested-by: Dan Carpenter Signed-off-by: David Howells Reviewed-by: Gao Xiang Reviewed-by: Jingbo Xu Reviewed-by: Dan Carpenter Link: https://lore.kernel.org/r/20220818111935.1683062-1-sunke32@huawei.com/ # v2 Link: https://lore.kernel.org/r/20220818125038.2247720-1-sunke32@huawei.com/ # v3 Link: https://lore.kernel.org/r/20220826023515.3437469-1-sunke32@huawei.com/ # v4 --- fs/cachefiles/ondemand.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c index 1fee702d55293..7e1586bd5cf34 100644 --- a/fs/cachefiles/ondemand.c +++ b/fs/cachefiles/ondemand.c @@ -158,9 +158,13 @@ int cachefiles_ondemand_copen(struct cachefiles_cache *cache, char *args) /* fail OPEN request if daemon reports an error */ if (size < 0) { - if (!IS_ERR_VALUE(size)) - size = -EINVAL; - req->error = size; + if (!IS_ERR_VALUE(size)) { + req->error = -EINVAL; + ret = -EINVAL; + } else { + req->error = size; + ret = 0; + } goto out; } From 1122f40072731525c06b1371cfa30112b9b54d27 Mon Sep 17 00:00:00 2001 From: Xin Yin Date: Thu, 25 Aug 2022 10:09:45 +0800 Subject: [PATCH 3/3] cachefiles: make on-demand request distribution fairer For now, enqueuing and dequeuing on-demand requests all start from idx 0, this makes request distribution unfair. In the weighty concurrent I/O scenario, the request stored in higher idx will starve. Searching requests cyclically in cachefiles_ondemand_daemon_read, makes distribution fairer. Fixes: c8383054506c ("cachefiles: notify the user daemon when looking up cookie") Reported-by: Yongqing Li Signed-off-by: Xin Yin Signed-off-by: David Howells Reviewed-by: Jeffle Xu Reviewed-by: Gao Xiang Link: https://lore.kernel.org/r/20220817065200.11543-1-yinxin.x@bytedance.com/ # v1 Link: https://lore.kernel.org/r/20220825020945.2293-1-yinxin.x@bytedance.com/ # v2 --- fs/cachefiles/internal.h | 1 + fs/cachefiles/ondemand.c | 12 +++++++++--- 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h index 6cba2c6de2f96..2ad58c4652084 100644 --- a/fs/cachefiles/internal.h +++ b/fs/cachefiles/internal.h @@ -111,6 +111,7 @@ struct cachefiles_cache { char *tag; /* cache binding tag */ refcount_t unbind_pincount;/* refcount to do daemon unbind */ struct xarray reqs; /* xarray of pending on-demand requests */ + unsigned long req_id_next; struct xarray ondemand_ids; /* xarray for ondemand_id allocation */ u32 ondemand_id_next; }; diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c index 7e1586bd5cf34..0254ed39f68ce 100644 --- a/fs/cachefiles/ondemand.c +++ b/fs/cachefiles/ondemand.c @@ -242,14 +242,19 @@ ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache, unsigned long id = 0; size_t n; int ret = 0; - XA_STATE(xas, &cache->reqs, 0); + XA_STATE(xas, &cache->reqs, cache->req_id_next); /* - * Search for a request that has not ever been processed, to prevent - * requests from being processed repeatedly. + * Cyclically search for a request that has not ever been processed, + * to prevent requests from being processed repeatedly, and make + * request distribution fair. */ xa_lock(&cache->reqs); req = xas_find_marked(&xas, UINT_MAX, CACHEFILES_REQ_NEW); + if (!req && cache->req_id_next > 0) { + xas_set(&xas, 0); + req = xas_find_marked(&xas, cache->req_id_next - 1, CACHEFILES_REQ_NEW); + } if (!req) { xa_unlock(&cache->reqs); return 0; @@ -264,6 +269,7 @@ ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache, } xas_clear_mark(&xas, CACHEFILES_REQ_NEW); + cache->req_id_next = xas.xa_index + 1; xa_unlock(&cache->reqs); id = xas.xa_index;