From: trondmy@kernel.org
To: linux-nfs@vger.kernel.org
Subject: [PATCH 12/12] NFS: Reduce readdir stack usage
Date: Mon, 2 Nov 2020 13:06:58 -0500 [thread overview]
Message-ID: <20201102180658.6218-13-trondmy@kernel.org> (raw)
In-Reply-To: <20201102180658.6218-12-trondmy@kernel.org>
From: Trond Myklebust <trond.myklebust@hammerspace.com>
The descriptor and the struct nfs_entry are both large structures,
so don't allocate them from the stack.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
fs/nfs/dir.c | 88 +++++++++++++++++++++++++++-------------------------
1 file changed, 46 insertions(+), 42 deletions(-)
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index a2cebd365948..966e8fc6c9b7 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -144,7 +144,7 @@ struct nfs_cache_array {
struct nfs_cache_array_entry array[];
};
-typedef struct nfs_readdir_descriptor {
+struct nfs_readdir_descriptor {
struct file *file;
struct page *page;
struct dir_context *ctx;
@@ -163,7 +163,7 @@ typedef struct nfs_readdir_descriptor {
signed char duped;
bool plus;
bool eof;
-} nfs_readdir_descriptor_t;
+};
static void nfs_readdir_array_init(struct nfs_cache_array *array)
{
@@ -358,8 +358,8 @@ bool nfs_readdir_use_cookie(const struct file *filp)
return true;
}
-static
-int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
+static int nfs_readdir_search_for_pos(struct nfs_cache_array *array,
+ struct nfs_readdir_descriptor *desc)
{
loff_t diff = desc->ctx->pos - desc->current_index;
unsigned int index;
@@ -390,8 +390,8 @@ nfs_readdir_inode_mapping_valid(struct nfs_inode *nfsi)
return !test_bit(NFS_INO_INVALIDATING, &nfsi->flags);
}
-static
-int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
+static int nfs_readdir_search_for_cookie(struct nfs_cache_array *array,
+ struct nfs_readdir_descriptor *desc)
{
int i;
loff_t new_pos;
@@ -439,8 +439,7 @@ int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_des
return status;
}
-static
-int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc)
+static int nfs_readdir_search_array(struct nfs_readdir_descriptor *desc)
{
struct nfs_cache_array *array;
int status;
@@ -493,7 +492,7 @@ static int nfs_readdir_xdr_filler(struct nfs_readdir_descriptor *desc,
return error;
}
-static int xdr_decode(nfs_readdir_descriptor_t *desc,
+static int xdr_decode(struct nfs_readdir_descriptor *desc,
struct nfs_entry *entry, struct xdr_stream *xdr)
{
struct inode *inode = file_inode(desc->file);
@@ -757,27 +756,28 @@ static struct page **nfs_readdir_alloc_pages(size_t npages)
return NULL;
}
-static
-int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
+static int nfs_readdir_xdr_to_array(struct nfs_readdir_descriptor *desc,
+ struct page *page, struct inode *inode)
{
struct page **pages;
- struct nfs_entry entry;
+ struct nfs_entry *entry;
size_t array_size;
size_t dtsize = NFS_SERVER(inode)->dtsize;
int status = -ENOMEM;
- entry.prev_cookie = 0;
- entry.cookie = nfs_readdir_page_last_cookie(page);
- entry.eof = 0;
- entry.fh = nfs_alloc_fhandle();
- entry.fattr = nfs_alloc_fattr();
- entry.server = NFS_SERVER(inode);
- if (entry.fh == NULL || entry.fattr == NULL)
+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ return -ENOMEM;
+ entry->cookie = nfs_readdir_page_last_cookie(page);
+ entry->fh = nfs_alloc_fhandle();
+ entry->fattr = nfs_alloc_fattr();
+ entry->server = NFS_SERVER(inode);
+ if (entry->fh == NULL || entry->fattr == NULL)
goto out;
- entry.label = nfs4_label_alloc(NFS_SERVER(inode), GFP_NOWAIT);
- if (IS_ERR(entry.label)) {
- status = PTR_ERR(entry.label);
+ entry->label = nfs4_label_alloc(NFS_SERVER(inode), GFP_NOWAIT);
+ if (IS_ERR(entry->label)) {
+ status = PTR_ERR(entry->label);
goto out;
}
@@ -788,7 +788,7 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page,
do {
unsigned int pglen;
- status = nfs_readdir_xdr_filler(desc, entry.cookie,
+ status = nfs_readdir_xdr_filler(desc, entry->cookie,
pages, dtsize);
if (status < 0)
break;
@@ -799,15 +799,16 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page,
break;
}
- status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen);
+ status = nfs_readdir_page_filler(desc, entry, pages, page, pglen);
} while (!status && nfs_readdir_page_needs_filling(page));
nfs_readdir_free_pages(pages, array_size);
out_release_label:
- nfs4_label_free(entry.label);
+ nfs4_label_free(entry->label);
out:
- nfs_free_fattr(entry.fattr);
- nfs_free_fhandle(entry.fh);
+ nfs_free_fattr(entry->fattr);
+ nfs_free_fhandle(entry->fh);
+ kfree(entry);
return status;
}
@@ -829,8 +830,7 @@ nfs_readdir_page_get_cached(struct nfs_readdir_descriptor *desc)
* Returns 0 if desc->dir_cookie was found on page desc->page_index
* and locks the page to prevent removal from the page cache.
*/
-static
-int find_and_lock_cache_page(nfs_readdir_descriptor_t *desc)
+static int find_and_lock_cache_page(struct nfs_readdir_descriptor *desc)
{
struct inode *inode = file_inode(desc->file);
struct nfs_inode *nfsi = NFS_I(inode);
@@ -856,8 +856,7 @@ int find_and_lock_cache_page(nfs_readdir_descriptor_t *desc)
}
/* Search for desc->dir_cookie from the beginning of the page cache */
-static inline
-int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
+static int readdir_search_pagecache(struct nfs_readdir_descriptor *desc)
{
int res;
@@ -922,8 +921,7 @@ static void nfs_do_filldir(struct nfs_readdir_descriptor *desc)
* we should already have a complete representation of the
* directory in the page cache by the time we get here.
*/
-static inline
-int uncached_readdir(nfs_readdir_descriptor_t *desc)
+static int uncached_readdir(struct nfs_readdir_descriptor *desc)
{
struct page *page = NULL;
int status;
@@ -968,13 +966,8 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
struct dentry *dentry = file_dentry(file);
struct inode *inode = d_inode(dentry);
struct nfs_open_dir_context *dir_ctx = file->private_data;
- nfs_readdir_descriptor_t my_desc = {
- .file = file,
- .ctx = ctx,
- .plus = nfs_use_readdirplus(inode, ctx),
- },
- *desc = &my_desc;
- int res = 0;
+ struct nfs_readdir_descriptor *desc;
+ int res;
dfprintk(FILE, "NFS: readdir(%pD2) starting at cookie %llu\n",
file, (long long)ctx->pos);
@@ -986,10 +979,19 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
* to either find the entry with the appropriate number or
* revalidate the cookie.
*/
- if (ctx->pos == 0 || nfs_attribute_cache_expired(inode))
+ if (ctx->pos == 0 || nfs_attribute_cache_expired(inode)) {
res = nfs_revalidate_mapping(inode, file->f_mapping);
- if (res < 0)
+ if (res < 0)
+ goto out;
+ }
+
+ res = -ENOMEM;
+ desc = kzalloc(sizeof(*desc), GFP_KERNEL);
+ if (!desc)
goto out;
+ desc->file = file;
+ desc->ctx = ctx;
+ desc->plus = nfs_use_readdirplus(inode, ctx);
spin_lock(&file->f_lock);
desc->dir_cookie = dir_ctx->dir_cookie;
@@ -1035,6 +1037,8 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
dir_ctx->attr_gencount = desc->attr_gencount;
spin_unlock(&file->f_lock);
+ kfree(desc);
+
out:
dfprintk(FILE, "NFS: readdir(%pD2) returns %d\n", file, res);
return res;
--
2.28.0
next prev parent reply other threads:[~2020-11-02 18:17 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-02 18:06 [PATCH 00/12] Readdir enhancements trondmy
2020-11-02 18:06 ` [PATCH 01/12] NFS: Ensure contents of struct nfs_open_dir_context are consistent trondmy
2020-11-02 18:06 ` [PATCH 02/12] NFS: Clean up readdir struct nfs_cache_array trondmy
2020-11-02 18:06 ` [PATCH 03/12] NFS: Clean up nfs_readdir_page_filler() trondmy
2020-11-02 18:06 ` [PATCH 04/12] NFS: Clean up directory array handling trondmy
2020-11-02 18:06 ` [PATCH 05/12] NFS: Don't discard readdir results trondmy
2020-11-02 18:06 ` [PATCH 06/12] NFS: Remove unnecessary kmap in nfs_readdir_xdr_to_array() trondmy
2020-11-02 18:06 ` [PATCH 07/12] NFS: Replace kmap() with kmap_atomic() in nfs_readdir_search_array() trondmy
2020-11-02 18:06 ` [PATCH 08/12] NFS: Simplify struct nfs_cache_array_entry trondmy
2020-11-02 18:06 ` [PATCH 09/12] NFS: Support larger readdir buffers trondmy
2020-11-02 18:06 ` [PATCH 10/12] NFS: More readdir cleanups trondmy
2020-11-02 18:06 ` [PATCH 11/12] NFS: nfs_do_filldir() does not return a value trondmy
2020-11-02 18:06 ` trondmy [this message]
2020-11-03 14:18 ` [PATCH 03/12] NFS: Clean up nfs_readdir_page_filler() Benjamin Coddington
2020-11-03 14:24 ` Benjamin Coddington
2020-11-03 13:35 ` [PATCH 02/12] NFS: Clean up readdir struct nfs_cache_array Benjamin Coddington
2020-11-03 14:09 ` Benjamin Coddington
2020-11-03 14:34 ` Benjamin Coddington
2020-11-02 20:40 ` [PATCH 00/12] Readdir enhancements David Wysochanski
2020-11-02 21:32 ` Trond Myklebust
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