From: trondmy@kernel.org
To: linux-nfs@vger.kernel.org
Subject: [PATCH v10 24/26] NFS: Fix up forced readdirplus
Date: Sun, 13 Mar 2022 13:05:55 -0400 [thread overview]
Message-ID: <20220313170557.5940-25-trondmy@kernel.org> (raw)
In-Reply-To: <20220313170557.5940-24-trondmy@kernel.org>
From: Trond Myklebust <trond.myklebust@hammerspace.com>
Avoid clearing the entire readdir page cache if we're just doing forced
readdirplus for the 'ls -l' heuristic.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
fs/nfs/dir.c | 56 +++++++++++++++++++++++++++++-------------
fs/nfs/nfstrace.h | 1 +
include/linux/nfs_fs.h | 1 +
3 files changed, 41 insertions(+), 17 deletions(-)
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 8c2552d89310..f6aac1e8a8b9 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -170,6 +170,7 @@ struct nfs_readdir_descriptor {
unsigned int cache_entry_index;
unsigned int buffer_fills;
unsigned int dtsize;
+ bool clear_cache;
bool plus;
bool eob;
bool eof;
@@ -227,6 +228,13 @@ static void nfs_readdir_clear_array(struct page *page)
kunmap_atomic(array);
}
+static void nfs_readdir_page_reinit_array(struct page *page, u64 last_cookie,
+ u64 change_attr)
+{
+ nfs_readdir_clear_array(page);
+ nfs_readdir_page_init_array(page, last_cookie, change_attr);
+}
+
static struct page *
nfs_readdir_page_array_alloc(u64 last_cookie, gfp_t gfp_flags)
{
@@ -428,12 +436,11 @@ static struct page *nfs_readdir_page_get_next(struct address_space *mapping,
struct page *page;
page = nfs_readdir_page_get_locked(mapping, cookie, change_attr);
- if (page) {
- if (nfs_readdir_page_last_cookie(page) == cookie)
- return page;
- nfs_readdir_page_unlock_and_put(page);
- }
- return NULL;
+ if (!page)
+ return NULL;
+ if (nfs_readdir_page_last_cookie(page) != cookie)
+ nfs_readdir_page_reinit_array(page, cookie, change_attr);
+ return page;
}
static inline
@@ -960,9 +967,15 @@ nfs_readdir_page_get_cached(struct nfs_readdir_descriptor *desc)
{
struct address_space *mapping = desc->file->f_mapping;
u64 change_attr = inode_peek_iversion_raw(mapping->host);
+ u64 cookie = desc->last_cookie;
+ struct page *page;
- return nfs_readdir_page_get_locked(mapping, desc->last_cookie,
- change_attr);
+ page = nfs_readdir_page_get_locked(mapping, cookie, change_attr);
+ if (!page)
+ return NULL;
+ if (desc->clear_cache && !nfs_readdir_page_needs_filling(page))
+ nfs_readdir_page_reinit_array(page, cookie, change_attr);
+ return page;
}
/*
@@ -1013,6 +1026,7 @@ static int find_and_lock_cache_page(struct nfs_readdir_descriptor *desc)
trace_nfs_readdir_invalidate_cache_range(
inode, 1, MAX_LFS_FILESIZE);
}
+ desc->clear_cache = false;
}
res = nfs_readdir_search_array(desc);
if (res == 0)
@@ -1147,16 +1161,17 @@ static int uncached_readdir(struct nfs_readdir_descriptor *desc)
#define NFS_READDIR_CACHE_MISS_THRESHOLD (16UL)
-static void nfs_readdir_handle_cache_misses(struct inode *inode,
+static bool nfs_readdir_handle_cache_misses(struct inode *inode,
struct nfs_readdir_descriptor *desc,
- unsigned int cache_misses)
+ unsigned int cache_misses,
+ bool force_clear)
{
- if (desc->ctx->pos == 0 ||
- cache_misses <= NFS_READDIR_CACHE_MISS_THRESHOLD)
- return;
- if (invalidate_mapping_pages(inode->i_mapping, 0, -1) == 0)
- return;
- trace_nfs_readdir_invalidate_cache_range(inode, 0, MAX_LFS_FILESIZE);
+ if (desc->ctx->pos == 0 || !desc->plus)
+ return false;
+ if (cache_misses <= NFS_READDIR_CACHE_MISS_THRESHOLD && !force_clear)
+ return false;
+ trace_nfs_readdir_force_readdirplus(inode);
+ return true;
}
/* The file offset position represents the dirent entry number. A
@@ -1171,6 +1186,7 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
struct nfs_open_dir_context *dir_ctx = file->private_data;
struct nfs_readdir_descriptor *desc;
unsigned int cache_hits, cache_misses;
+ bool force_clear;
int res;
dfprintk(FILE, "NFS: readdir(%pD2) starting at cookie %llu\n",
@@ -1203,6 +1219,7 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
memcpy(desc->verf, dir_ctx->verf, sizeof(desc->verf));
cache_hits = atomic_xchg(&dir_ctx->cache_hits, 0);
cache_misses = atomic_xchg(&dir_ctx->cache_misses, 0);
+ force_clear = dir_ctx->force_clear;
spin_unlock(&file->f_lock);
if (desc->eof) {
@@ -1211,7 +1228,9 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
}
desc->plus = nfs_use_readdirplus(inode, ctx, cache_hits, cache_misses);
- nfs_readdir_handle_cache_misses(inode, desc, cache_misses);
+ force_clear = nfs_readdir_handle_cache_misses(inode, desc, cache_misses,
+ force_clear);
+ desc->clear_cache = force_clear;
do {
res = readdir_search_pagecache(desc);
@@ -1240,6 +1259,8 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
nfs_do_filldir(desc, nfsi->cookieverf);
nfs_readdir_page_unlock_and_put_cached(desc);
+ if (desc->page_index == desc->page_index_max)
+ desc->clear_cache = force_clear;
} while (!desc->eob && !desc->eof);
spin_lock(&file->f_lock);
@@ -1247,6 +1268,7 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
dir_ctx->last_cookie = desc->last_cookie;
dir_ctx->attr_gencount = desc->attr_gencount;
dir_ctx->page_index = desc->page_index;
+ dir_ctx->force_clear = force_clear;
dir_ctx->eof = desc->eof;
dir_ctx->dtsize = desc->dtsize;
memcpy(dir_ctx->verf, desc->verf, sizeof(dir_ctx->verf));
diff --git a/fs/nfs/nfstrace.h b/fs/nfs/nfstrace.h
index ec2645d20abf..59f4ca803fd0 100644
--- a/fs/nfs/nfstrace.h
+++ b/fs/nfs/nfstrace.h
@@ -160,6 +160,7 @@ DEFINE_NFS_INODE_EVENT(nfs_fsync_enter);
DEFINE_NFS_INODE_EVENT_DONE(nfs_fsync_exit);
DEFINE_NFS_INODE_EVENT(nfs_access_enter);
DEFINE_NFS_INODE_EVENT_DONE(nfs_set_cache_invalid);
+DEFINE_NFS_INODE_EVENT(nfs_readdir_force_readdirplus);
DEFINE_NFS_INODE_EVENT_DONE(nfs_readdir_cache_fill_done);
DEFINE_NFS_INODE_EVENT_DONE(nfs_readdir_uncached_done);
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 42aad886d3c0..3893386ceaed 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -109,6 +109,7 @@ struct nfs_open_dir_context {
__u64 last_cookie;
pgoff_t page_index;
unsigned int dtsize;
+ bool force_clear;
bool eof;
struct rcu_head rcu_head;
};
--
2.35.1
next prev parent reply other threads:[~2022-03-13 17:12 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-13 17:05 [PATCH v10 00/26] Readdir improvements trondmy
2022-03-13 17:05 ` [PATCH v10 01/26] NFS: Return valid errors from nfs2/3_decode_dirent() trondmy
2022-03-13 17:05 ` [PATCH v10 02/26] NFS: constify nfs_server_capable() and nfs_have_writebacks() trondmy
2022-03-13 17:05 ` [PATCH v10 03/26] NFS: Trace lookup revalidation failure trondmy
2022-03-13 17:05 ` [PATCH v10 04/26] NFS: Initialise the readdir verifier as best we can in nfs_opendir() trondmy
2022-03-13 17:05 ` [PATCH v10 05/26] NFS: Use kzalloc() to avoid initialising the nfs_open_dir_context trondmy
2022-03-13 17:05 ` [PATCH v10 06/26] NFS: Calculate page offsets algorithmically trondmy
2022-03-13 17:05 ` [PATCH v10 07/26] NFS: Store the change attribute in the directory page cache trondmy
2022-03-13 17:05 ` [PATCH v10 08/26] NFS: Don't re-read the entire page cache to find the next cookie trondmy
2022-03-13 17:05 ` [PATCH v10 09/26] NFS: Don't advance the page pointer unless the page is full trondmy
2022-03-13 17:05 ` [PATCH v10 10/26] NFS: Adjust the amount of readahead performed by NFS readdir trondmy
2022-03-13 17:05 ` [PATCH v10 11/26] NFS: If the cookie verifier changes, we must invalidate the page cache trondmy
2022-03-13 17:05 ` [PATCH v10 12/26] NFS: Simplify nfs_readdir_xdr_to_array() trondmy
2022-03-13 17:05 ` [PATCH v10 13/26] NFS: Reduce use of uncached readdir trondmy
2022-03-13 17:05 ` [PATCH v10 14/26] NFS: Improve heuristic for readdirplus trondmy
2022-03-13 17:05 ` [PATCH v10 15/26] NFS: Don't ask for readdirplus unless it can help nfs_getattr() trondmy
2022-03-13 17:05 ` [PATCH v10 16/26] NFSv4: Ask for a full XDR buffer of readdir goodness trondmy
2022-03-13 17:05 ` [PATCH v10 17/26] NFS: Readdirplus can't help lookup for case insensitive filesystems trondmy
2022-03-13 17:05 ` [PATCH v10 18/26] NFS: Don't request readdirplus when revalidation was forced trondmy
2022-03-13 17:05 ` [PATCH v10 19/26] NFS: Add basic readdir tracing trondmy
2022-03-13 17:05 ` [PATCH v10 20/26] NFS: Trace effects of readdirplus on the dcache trondmy
2022-03-13 17:05 ` [PATCH v10 21/26] NFS: Trace effects of the readdirplus heuristic trondmy
2022-03-13 17:05 ` [PATCH v10 22/26] NFS: Clean up page array initialisation/free trondmy
2022-03-13 17:05 ` [PATCH v10 23/26] NFS: Convert readdir page cache to use a cookie based index trondmy
2022-03-13 17:05 ` trondmy [this message]
2022-03-13 17:05 ` [PATCH v10 25/26] NFS: Optimise away the previous cookie field trondmy
2022-03-13 17:05 ` [PATCH v10 26/26] NFS: Cache all entries in the readdirplus reply trondmy
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220313170557.5940-25-trondmy@kernel.org \
--to=trondmy@kernel.org \
--cc=linux-nfs@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.