From b0365ccb0712efacf99936e94e92eb7ae63de4d5 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 23 Feb 2022 13:29:59 -0500 Subject: NFS: Fix up forced readdirplus Avoid clearing the entire readdir page cache if we're just doing forced readdirplus for the 'ls -l' heuristic. Signed-off-by: Trond Myklebust --- fs/nfs/dir.c | 56 +++++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 39 insertions(+), 17 deletions(-) (limited to 'fs/nfs/dir.c') 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 @@ out: #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)); -- cgit v1.2.3