mirror of https://gitee.com/openkylin/linux.git
NFS: Use the 64-bit server readdir cookies when possible
When we're running as a 64-bit architecture and are not running in 32-bit compatibility mode, it is better to use the 64-bit readdir cookies that supplied by the server. Doing so improves the accuracy of telldir()/seekdir(), particularly when the directory is changing, for instance, when doing 'rm -rf'. We still fall back to using the 32-bit offsets on 32-bit architectures and when in compatibility mode. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
Trond Myklebust
parent
fb33c6510d
commit
59e356a967
57
fs/nfs/dir.c
57
fs/nfs/dir.c
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@ -144,7 +144,6 @@ struct nfs_cache_array {
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struct nfs_cache_array_entry array[0];
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};
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typedef int (*decode_dirent_t)(struct xdr_stream *, struct nfs_entry *, bool);
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typedef struct {
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struct file *file;
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struct page *page;
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@ -153,7 +152,7 @@ typedef struct {
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u64 *dir_cookie;
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u64 last_cookie;
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loff_t current_index;
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decode_dirent_t decode;
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loff_t prev_index;
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unsigned long dir_verifier;
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unsigned long timestamp;
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@ -240,6 +239,25 @@ int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
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return ret;
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}
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static inline
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int is_32bit_api(void)
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{
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#ifdef CONFIG_COMPAT
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return in_compat_syscall();
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#else
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return (BITS_PER_LONG == 32);
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#endif
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}
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static
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bool nfs_readdir_use_cookie(const struct file *filp)
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{
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if ((filp->f_mode & FMODE_32BITHASH) ||
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(!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
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return false;
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return true;
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}
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static
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int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
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{
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@ -289,7 +307,7 @@ int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_des
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!nfs_readdir_inode_mapping_valid(nfsi)) {
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ctx->duped = 0;
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ctx->attr_gencount = nfsi->attr_gencount;
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} else if (new_pos < desc->ctx->pos) {
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} else if (new_pos < desc->prev_index) {
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if (ctx->duped > 0
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&& ctx->dup_cookie == *desc->dir_cookie) {
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if (printk_ratelimit()) {
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@ -305,7 +323,11 @@ int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_des
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ctx->dup_cookie = *desc->dir_cookie;
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ctx->duped = -1;
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}
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if (nfs_readdir_use_cookie(desc->file))
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desc->ctx->pos = *desc->dir_cookie;
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else
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desc->ctx->pos = new_pos;
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desc->prev_index = new_pos;
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desc->cache_entry_index = i;
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return 0;
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}
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@ -376,9 +398,10 @@ int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc,
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static int xdr_decode(nfs_readdir_descriptor_t *desc,
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struct nfs_entry *entry, struct xdr_stream *xdr)
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{
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struct inode *inode = file_inode(desc->file);
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int error;
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error = desc->decode(xdr, entry, desc->plus);
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error = NFS_PROTO(inode)->decode_dirent(xdr, entry, desc->plus);
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if (error)
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return error;
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entry->fattr->time_start = desc->timestamp;
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@ -756,6 +779,7 @@ int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
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if (desc->page_index == 0) {
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desc->current_index = 0;
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desc->prev_index = 0;
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desc->last_cookie = 0;
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}
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do {
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@ -786,11 +810,14 @@ int nfs_do_filldir(nfs_readdir_descriptor_t *desc)
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desc->eof = true;
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break;
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}
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desc->ctx->pos++;
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if (i < (array->size-1))
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*desc->dir_cookie = array->array[i+1].cookie;
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else
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*desc->dir_cookie = array->last_cookie;
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if (nfs_readdir_use_cookie(file))
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desc->ctx->pos = *desc->dir_cookie;
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else
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desc->ctx->pos++;
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if (ctx->duped != 0)
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ctx->duped = 1;
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}
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@ -860,9 +887,14 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
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{
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struct dentry *dentry = file_dentry(file);
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struct inode *inode = d_inode(dentry);
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nfs_readdir_descriptor_t my_desc,
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*desc = &my_desc;
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struct nfs_open_dir_context *dir_ctx = file->private_data;
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nfs_readdir_descriptor_t my_desc = {
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.file = file,
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.ctx = ctx,
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.dir_cookie = &dir_ctx->dir_cookie,
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.plus = nfs_use_readdirplus(inode, ctx),
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},
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*desc = &my_desc;
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int res = 0;
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dfprintk(FILE, "NFS: readdir(%pD2) starting at cookie %llu\n",
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@ -875,14 +907,6 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
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* to either find the entry with the appropriate number or
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* revalidate the cookie.
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*/
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memset(desc, 0, sizeof(*desc));
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desc->file = file;
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desc->ctx = ctx;
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desc->dir_cookie = &dir_ctx->dir_cookie;
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desc->decode = NFS_PROTO(inode)->decode_dirent;
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desc->plus = nfs_use_readdirplus(inode, ctx);
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if (ctx->pos == 0 || nfs_attribute_cache_expired(inode))
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res = nfs_revalidate_mapping(inode, file->f_mapping);
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if (res < 0)
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@ -954,6 +978,9 @@ static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)
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}
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if (offset != filp->f_pos) {
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filp->f_pos = offset;
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if (nfs_readdir_use_cookie(filp))
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dir_ctx->dir_cookie = offset;
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else
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dir_ctx->dir_cookie = 0;
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dir_ctx->duped = 0;
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}
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