From: Trond Myklebust <[email protected]>
Avoid clearing the entire readdir page cache if we're just doing forced
readdirplus for the 'ls -l' heuristic.
Signed-off-by: Trond Myklebust <[email protected]>
---
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
From: Trond Myklebust <[email protected]>
Replace the 'previous cookie' field in struct nfs_entry with the
array->last_cookie.
Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/dir.c | 26 ++++++++++++++------------
fs/nfs/nfs2xdr.c | 1 -
fs/nfs/nfs3xdr.c | 1 -
fs/nfs/nfs4xdr.c | 1 -
include/linux/nfs_xdr.h | 3 +--
5 files changed, 15 insertions(+), 17 deletions(-)
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index f6aac1e8a8b9..033249a72e92 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -301,19 +301,20 @@ static int nfs_readdir_array_can_expand(struct nfs_cache_array *array)
return 0;
}
-static
-int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
+static int nfs_readdir_page_array_append(struct page *page,
+ const struct nfs_entry *entry,
+ u64 *cookie)
{
struct nfs_cache_array *array;
struct nfs_cache_array_entry *cache_entry;
const char *name;
- int ret;
+ int ret = -ENOMEM;
name = nfs_readdir_copy_name(entry->name, entry->len);
- if (!name)
- return -ENOMEM;
array = kmap_atomic(page);
+ if (!name)
+ goto out;
ret = nfs_readdir_array_can_expand(array);
if (ret) {
kfree(name);
@@ -321,7 +322,7 @@ int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
}
cache_entry = &array->array[array->size];
- cache_entry->cookie = entry->prev_cookie;
+ cache_entry->cookie = array->last_cookie;
cache_entry->ino = entry->ino;
cache_entry->d_type = entry->d_type;
cache_entry->name_len = entry->len;
@@ -333,6 +334,7 @@ int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
if (entry->eof != 0)
nfs_readdir_array_set_eof(array);
out:
+ *cookie = array->last_cookie;
kunmap_atomic(array);
return ret;
}
@@ -798,6 +800,7 @@ static int nfs_readdir_page_filler(struct nfs_readdir_descriptor *desc,
struct xdr_stream stream;
struct xdr_buf buf;
struct page *scratch, *new, *page = *arrays;
+ u64 cookie;
int status;
scratch = alloc_page(GFP_KERNEL);
@@ -819,22 +822,21 @@ static int nfs_readdir_page_filler(struct nfs_readdir_descriptor *desc,
nfs_prime_dcache(file_dentry(desc->file), entry,
desc->dir_verifier);
- status = nfs_readdir_add_to_array(entry, page);
+ status = nfs_readdir_page_array_append(page, entry, &cookie);
if (status != -ENOSPC)
continue;
if (page->mapping != mapping) {
if (!--narrays)
break;
- new = nfs_readdir_page_array_alloc(entry->prev_cookie,
- GFP_KERNEL);
+ new = nfs_readdir_page_array_alloc(cookie, GFP_KERNEL);
if (!new)
break;
arrays++;
*arrays = page = new;
} else {
- new = nfs_readdir_page_get_next(
- mapping, entry->prev_cookie, change_attr);
+ new = nfs_readdir_page_get_next(mapping, cookie,
+ change_attr);
if (!new)
break;
if (page != *arrays)
@@ -842,7 +844,7 @@ static int nfs_readdir_page_filler(struct nfs_readdir_descriptor *desc,
page = new;
}
desc->page_index_max++;
- status = nfs_readdir_add_to_array(entry, page);
+ status = nfs_readdir_page_array_append(page, entry, &cookie);
} while (!status && !entry->eof);
switch (status) {
diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index 3d5ba43f44bb..05c3b4b2b3dd 100644
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -955,7 +955,6 @@ int nfs2_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
* The type (size and byte order) of nfscookie isn't defined in
* RFC 1094. This implementation assumes that it's an XDR uint32.
*/
- entry->prev_cookie = entry->cookie;
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
return -EAGAIN;
diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
index d6779ceeb39e..3b0b650c9c5a 100644
--- a/fs/nfs/nfs3xdr.c
+++ b/fs/nfs/nfs3xdr.c
@@ -2024,7 +2024,6 @@ int nfs3_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
zero_nfs_fh3(entry->fh);
}
- entry->prev_cookie = entry->cookie;
entry->cookie = new_cookie;
return 0;
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index b7780b97dc4d..86a5f6516928 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -7508,7 +7508,6 @@ int nfs4_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
if (entry->fattr->valid & NFS_ATTR_FATTR_TYPE)
entry->d_type = nfs_umode_to_dtype(entry->fattr->mode);
- entry->prev_cookie = entry->cookie;
entry->cookie = new_cookie;
return 0;
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 728cb0c1f0b6..82f7c2730b9a 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -745,8 +745,7 @@ struct nfs_auth_info {
*/
struct nfs_entry {
__u64 ino;
- __u64 cookie,
- prev_cookie;
+ __u64 cookie;
const char * name;
unsigned int len;
int eof;
--
2.35.1