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2811 lines
71 KiB
2811 lines
71 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* linux/fs/nfs/dir.c |
|
* |
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* Copyright (C) 1992 Rick Sladkey |
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* |
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* nfs directory handling functions |
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* |
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* 10 Apr 1996 Added silly rename for unlink --okir |
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* 28 Sep 1996 Improved directory cache --okir |
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* 23 Aug 1997 Claus Heine [email protected] |
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* Re-implemented silly rename for unlink, newly implemented |
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* silly rename for nfs_rename() following the suggestions |
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* of Olaf Kirch (okir) found in this file. |
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* Following Linus comments on my original hack, this version |
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* depends only on the dcache stuff and doesn't touch the inode |
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* layer (iput() and friends). |
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* 6 Jun 1999 Cache readdir lookups in the page cache. -DaveM |
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*/ |
|
|
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#include <linux/module.h> |
|
#include <linux/time.h> |
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#include <linux/errno.h> |
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#include <linux/stat.h> |
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#include <linux/fcntl.h> |
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#include <linux/string.h> |
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#include <linux/kernel.h> |
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#include <linux/slab.h> |
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#include <linux/mm.h> |
|
#include <linux/sunrpc/clnt.h> |
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#include <linux/nfs_fs.h> |
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#include <linux/nfs_mount.h> |
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#include <linux/pagemap.h> |
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#include <linux/pagevec.h> |
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#include <linux/namei.h> |
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#include <linux/mount.h> |
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#include <linux/swap.h> |
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#include <linux/sched.h> |
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#include <linux/kmemleak.h> |
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#include <linux/xattr.h> |
|
|
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#include "delegation.h" |
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#include "iostat.h" |
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#include "internal.h" |
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#include "fscache.h" |
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|
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#include "nfstrace.h" |
|
|
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/* #define NFS_DEBUG_VERBOSE 1 */ |
|
|
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static int nfs_opendir(struct inode *, struct file *); |
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static int nfs_closedir(struct inode *, struct file *); |
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static int nfs_readdir(struct file *, struct dir_context *); |
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static int nfs_fsync_dir(struct file *, loff_t, loff_t, int); |
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static loff_t nfs_llseek_dir(struct file *, loff_t, int); |
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static void nfs_readdir_clear_array(struct page*); |
|
|
|
const struct file_operations nfs_dir_operations = { |
|
.llseek = nfs_llseek_dir, |
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.read = generic_read_dir, |
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.iterate_shared = nfs_readdir, |
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.open = nfs_opendir, |
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.release = nfs_closedir, |
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.fsync = nfs_fsync_dir, |
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}; |
|
|
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const struct address_space_operations nfs_dir_aops = { |
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.freepage = nfs_readdir_clear_array, |
|
}; |
|
|
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static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct inode *dir, const struct cred *cred) |
|
{ |
|
struct nfs_inode *nfsi = NFS_I(dir); |
|
struct nfs_open_dir_context *ctx; |
|
ctx = kmalloc(sizeof(*ctx), GFP_KERNEL); |
|
if (ctx != NULL) { |
|
ctx->duped = 0; |
|
ctx->attr_gencount = nfsi->attr_gencount; |
|
ctx->dir_cookie = 0; |
|
ctx->dup_cookie = 0; |
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ctx->cred = get_cred(cred); |
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spin_lock(&dir->i_lock); |
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if (list_empty(&nfsi->open_files) && |
|
(nfsi->cache_validity & NFS_INO_DATA_INVAL_DEFER)) |
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nfsi->cache_validity |= NFS_INO_INVALID_DATA | |
|
NFS_INO_REVAL_FORCED; |
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list_add(&ctx->list, &nfsi->open_files); |
|
spin_unlock(&dir->i_lock); |
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return ctx; |
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} |
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return ERR_PTR(-ENOMEM); |
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} |
|
|
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static void put_nfs_open_dir_context(struct inode *dir, struct nfs_open_dir_context *ctx) |
|
{ |
|
spin_lock(&dir->i_lock); |
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list_del(&ctx->list); |
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spin_unlock(&dir->i_lock); |
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put_cred(ctx->cred); |
|
kfree(ctx); |
|
} |
|
|
|
/* |
|
* Open file |
|
*/ |
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static int |
|
nfs_opendir(struct inode *inode, struct file *filp) |
|
{ |
|
int res = 0; |
|
struct nfs_open_dir_context *ctx; |
|
|
|
dfprintk(FILE, "NFS: open dir(%pD2)\n", filp); |
|
|
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nfs_inc_stats(inode, NFSIOS_VFSOPEN); |
|
|
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ctx = alloc_nfs_open_dir_context(inode, current_cred()); |
|
if (IS_ERR(ctx)) { |
|
res = PTR_ERR(ctx); |
|
goto out; |
|
} |
|
filp->private_data = ctx; |
|
out: |
|
return res; |
|
} |
|
|
|
static int |
|
nfs_closedir(struct inode *inode, struct file *filp) |
|
{ |
|
put_nfs_open_dir_context(file_inode(filp), filp->private_data); |
|
return 0; |
|
} |
|
|
|
struct nfs_cache_array_entry { |
|
u64 cookie; |
|
u64 ino; |
|
struct qstr string; |
|
unsigned char d_type; |
|
}; |
|
|
|
struct nfs_cache_array { |
|
int size; |
|
int eof_index; |
|
u64 last_cookie; |
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struct nfs_cache_array_entry array[]; |
|
}; |
|
|
|
typedef struct { |
|
struct file *file; |
|
struct page *page; |
|
struct dir_context *ctx; |
|
unsigned long page_index; |
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u64 *dir_cookie; |
|
u64 last_cookie; |
|
loff_t current_index; |
|
loff_t prev_index; |
|
|
|
unsigned long dir_verifier; |
|
unsigned long timestamp; |
|
unsigned long gencount; |
|
unsigned int cache_entry_index; |
|
bool plus; |
|
bool eof; |
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} nfs_readdir_descriptor_t; |
|
|
|
static |
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void nfs_readdir_init_array(struct page *page) |
|
{ |
|
struct nfs_cache_array *array; |
|
|
|
array = kmap_atomic(page); |
|
memset(array, 0, sizeof(struct nfs_cache_array)); |
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array->eof_index = -1; |
|
kunmap_atomic(array); |
|
} |
|
|
|
/* |
|
* we are freeing strings created by nfs_add_to_readdir_array() |
|
*/ |
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static |
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void nfs_readdir_clear_array(struct page *page) |
|
{ |
|
struct nfs_cache_array *array; |
|
int i; |
|
|
|
array = kmap_atomic(page); |
|
for (i = 0; i < array->size; i++) |
|
kfree(array->array[i].string.name); |
|
array->size = 0; |
|
kunmap_atomic(array); |
|
} |
|
|
|
/* |
|
* the caller is responsible for freeing qstr.name |
|
* when called by nfs_readdir_add_to_array, the strings will be freed in |
|
* nfs_clear_readdir_array() |
|
*/ |
|
static |
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int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len) |
|
{ |
|
string->len = len; |
|
string->name = kmemdup_nul(name, len, GFP_KERNEL); |
|
if (string->name == NULL) |
|
return -ENOMEM; |
|
/* |
|
* Avoid a kmemleak false positive. The pointer to the name is stored |
|
* in a page cache page which kmemleak does not scan. |
|
*/ |
|
kmemleak_not_leak(string->name); |
|
string->hash = full_name_hash(NULL, name, len); |
|
return 0; |
|
} |
|
|
|
static |
|
int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page) |
|
{ |
|
struct nfs_cache_array *array = kmap(page); |
|
struct nfs_cache_array_entry *cache_entry; |
|
int ret; |
|
|
|
cache_entry = &array->array[array->size]; |
|
|
|
/* Check that this entry lies within the page bounds */ |
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ret = -ENOSPC; |
|
if ((char *)&cache_entry[1] - (char *)page_address(page) > PAGE_SIZE) |
|
goto out; |
|
|
|
cache_entry->cookie = entry->prev_cookie; |
|
cache_entry->ino = entry->ino; |
|
cache_entry->d_type = entry->d_type; |
|
ret = nfs_readdir_make_qstr(&cache_entry->string, entry->name, entry->len); |
|
if (ret) |
|
goto out; |
|
array->last_cookie = entry->cookie; |
|
array->size++; |
|
if (entry->eof != 0) |
|
array->eof_index = array->size; |
|
out: |
|
kunmap(page); |
|
return ret; |
|
} |
|
|
|
static inline |
|
int is_32bit_api(void) |
|
{ |
|
#ifdef CONFIG_COMPAT |
|
return in_compat_syscall(); |
|
#else |
|
return (BITS_PER_LONG == 32); |
|
#endif |
|
} |
|
|
|
static |
|
bool nfs_readdir_use_cookie(const struct file *filp) |
|
{ |
|
if ((filp->f_mode & FMODE_32BITHASH) || |
|
(!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) |
|
return false; |
|
return true; |
|
} |
|
|
|
static |
|
int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc) |
|
{ |
|
loff_t diff = desc->ctx->pos - desc->current_index; |
|
unsigned int index; |
|
|
|
if (diff < 0) |
|
goto out_eof; |
|
if (diff >= array->size) { |
|
if (array->eof_index >= 0) |
|
goto out_eof; |
|
return -EAGAIN; |
|
} |
|
|
|
index = (unsigned int)diff; |
|
*desc->dir_cookie = array->array[index].cookie; |
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desc->cache_entry_index = index; |
|
return 0; |
|
out_eof: |
|
desc->eof = true; |
|
return -EBADCOOKIE; |
|
} |
|
|
|
static bool |
|
nfs_readdir_inode_mapping_valid(struct nfs_inode *nfsi) |
|
{ |
|
if (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA)) |
|
return false; |
|
smp_rmb(); |
|
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) |
|
{ |
|
int i; |
|
loff_t new_pos; |
|
int status = -EAGAIN; |
|
|
|
for (i = 0; i < array->size; i++) { |
|
if (array->array[i].cookie == *desc->dir_cookie) { |
|
struct nfs_inode *nfsi = NFS_I(file_inode(desc->file)); |
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struct nfs_open_dir_context *ctx = desc->file->private_data; |
|
|
|
new_pos = desc->current_index + i; |
|
if (ctx->attr_gencount != nfsi->attr_gencount || |
|
!nfs_readdir_inode_mapping_valid(nfsi)) { |
|
ctx->duped = 0; |
|
ctx->attr_gencount = nfsi->attr_gencount; |
|
} else if (new_pos < desc->prev_index) { |
|
if (ctx->duped > 0 |
|
&& ctx->dup_cookie == *desc->dir_cookie) { |
|
if (printk_ratelimit()) { |
|
pr_notice("NFS: directory %pD2 contains a readdir loop." |
|
"Please contact your server vendor. " |
|
"The file: %.*s has duplicate cookie %llu\n", |
|
desc->file, array->array[i].string.len, |
|
array->array[i].string.name, *desc->dir_cookie); |
|
} |
|
status = -ELOOP; |
|
goto out; |
|
} |
|
ctx->dup_cookie = *desc->dir_cookie; |
|
ctx->duped = -1; |
|
} |
|
if (nfs_readdir_use_cookie(desc->file)) |
|
desc->ctx->pos = *desc->dir_cookie; |
|
else |
|
desc->ctx->pos = new_pos; |
|
desc->prev_index = new_pos; |
|
desc->cache_entry_index = i; |
|
return 0; |
|
} |
|
} |
|
if (array->eof_index >= 0) { |
|
status = -EBADCOOKIE; |
|
if (*desc->dir_cookie == array->last_cookie) |
|
desc->eof = true; |
|
} |
|
out: |
|
return status; |
|
} |
|
|
|
static |
|
int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc) |
|
{ |
|
struct nfs_cache_array *array; |
|
int status; |
|
|
|
array = kmap(desc->page); |
|
|
|
if (*desc->dir_cookie == 0) |
|
status = nfs_readdir_search_for_pos(array, desc); |
|
else |
|
status = nfs_readdir_search_for_cookie(array, desc); |
|
|
|
if (status == -EAGAIN) { |
|
desc->last_cookie = array->last_cookie; |
|
desc->current_index += array->size; |
|
desc->page_index++; |
|
} |
|
kunmap(desc->page); |
|
return status; |
|
} |
|
|
|
/* Fill a page with xdr information before transferring to the cache page */ |
|
static |
|
int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc, |
|
struct nfs_entry *entry, struct file *file, struct inode *inode) |
|
{ |
|
struct nfs_open_dir_context *ctx = file->private_data; |
|
const struct cred *cred = ctx->cred; |
|
unsigned long timestamp, gencount; |
|
int error; |
|
|
|
again: |
|
timestamp = jiffies; |
|
gencount = nfs_inc_attr_generation_counter(); |
|
desc->dir_verifier = nfs_save_change_attribute(inode); |
|
error = NFS_PROTO(inode)->readdir(file_dentry(file), cred, entry->cookie, pages, |
|
NFS_SERVER(inode)->dtsize, desc->plus); |
|
if (error < 0) { |
|
/* We requested READDIRPLUS, but the server doesn't grok it */ |
|
if (error == -ENOTSUPP && desc->plus) { |
|
NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS; |
|
clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags); |
|
desc->plus = false; |
|
goto again; |
|
} |
|
goto error; |
|
} |
|
desc->timestamp = timestamp; |
|
desc->gencount = gencount; |
|
error: |
|
return error; |
|
} |
|
|
|
static int xdr_decode(nfs_readdir_descriptor_t *desc, |
|
struct nfs_entry *entry, struct xdr_stream *xdr) |
|
{ |
|
struct inode *inode = file_inode(desc->file); |
|
int error; |
|
|
|
error = NFS_PROTO(inode)->decode_dirent(xdr, entry, desc->plus); |
|
if (error) |
|
return error; |
|
entry->fattr->time_start = desc->timestamp; |
|
entry->fattr->gencount = desc->gencount; |
|
return 0; |
|
} |
|
|
|
/* Match file and dirent using either filehandle or fileid |
|
* Note: caller is responsible for checking the fsid |
|
*/ |
|
static |
|
int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry) |
|
{ |
|
struct inode *inode; |
|
struct nfs_inode *nfsi; |
|
|
|
if (d_really_is_negative(dentry)) |
|
return 0; |
|
|
|
inode = d_inode(dentry); |
|
if (is_bad_inode(inode) || NFS_STALE(inode)) |
|
return 0; |
|
|
|
nfsi = NFS_I(inode); |
|
if (entry->fattr->fileid != nfsi->fileid) |
|
return 0; |
|
if (entry->fh->size && nfs_compare_fh(entry->fh, &nfsi->fh) != 0) |
|
return 0; |
|
return 1; |
|
} |
|
|
|
static |
|
bool nfs_use_readdirplus(struct inode *dir, struct dir_context *ctx) |
|
{ |
|
if (!nfs_server_capable(dir, NFS_CAP_READDIRPLUS)) |
|
return false; |
|
if (test_and_clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags)) |
|
return true; |
|
if (ctx->pos == 0) |
|
return true; |
|
return false; |
|
} |
|
|
|
/* |
|
* This function is called by the lookup and getattr code to request the |
|
* use of readdirplus to accelerate any future lookups in the same |
|
* directory. |
|
*/ |
|
void nfs_advise_use_readdirplus(struct inode *dir) |
|
{ |
|
struct nfs_inode *nfsi = NFS_I(dir); |
|
|
|
if (nfs_server_capable(dir, NFS_CAP_READDIRPLUS) && |
|
!list_empty(&nfsi->open_files)) |
|
set_bit(NFS_INO_ADVISE_RDPLUS, &nfsi->flags); |
|
} |
|
|
|
/* |
|
* This function is mainly for use by nfs_getattr(). |
|
* |
|
* If this is an 'ls -l', we want to force use of readdirplus. |
|
* Do this by checking if there is an active file descriptor |
|
* and calling nfs_advise_use_readdirplus, then forcing a |
|
* cache flush. |
|
*/ |
|
void nfs_force_use_readdirplus(struct inode *dir) |
|
{ |
|
struct nfs_inode *nfsi = NFS_I(dir); |
|
|
|
if (nfs_server_capable(dir, NFS_CAP_READDIRPLUS) && |
|
!list_empty(&nfsi->open_files)) { |
|
set_bit(NFS_INO_ADVISE_RDPLUS, &nfsi->flags); |
|
invalidate_mapping_pages(dir->i_mapping, |
|
nfsi->page_index + 1, -1); |
|
} |
|
} |
|
|
|
static |
|
void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry, |
|
unsigned long dir_verifier) |
|
{ |
|
struct qstr filename = QSTR_INIT(entry->name, entry->len); |
|
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); |
|
struct dentry *dentry; |
|
struct dentry *alias; |
|
struct inode *inode; |
|
int status; |
|
|
|
if (!(entry->fattr->valid & NFS_ATTR_FATTR_FILEID)) |
|
return; |
|
if (!(entry->fattr->valid & NFS_ATTR_FATTR_FSID)) |
|
return; |
|
if (filename.len == 0) |
|
return; |
|
/* Validate that the name doesn't contain any illegal '\0' */ |
|
if (strnlen(filename.name, filename.len) != filename.len) |
|
return; |
|
/* ...or '/' */ |
|
if (strnchr(filename.name, filename.len, '/')) |
|
return; |
|
if (filename.name[0] == '.') { |
|
if (filename.len == 1) |
|
return; |
|
if (filename.len == 2 && filename.name[1] == '.') |
|
return; |
|
} |
|
filename.hash = full_name_hash(parent, filename.name, filename.len); |
|
|
|
dentry = d_lookup(parent, &filename); |
|
again: |
|
if (!dentry) { |
|
dentry = d_alloc_parallel(parent, &filename, &wq); |
|
if (IS_ERR(dentry)) |
|
return; |
|
} |
|
if (!d_in_lookup(dentry)) { |
|
/* Is there a mountpoint here? If so, just exit */ |
|
if (!nfs_fsid_equal(&NFS_SB(dentry->d_sb)->fsid, |
|
&entry->fattr->fsid)) |
|
goto out; |
|
if (nfs_same_file(dentry, entry)) { |
|
if (!entry->fh->size) |
|
goto out; |
|
nfs_set_verifier(dentry, dir_verifier); |
|
status = nfs_refresh_inode(d_inode(dentry), entry->fattr); |
|
if (!status) |
|
nfs_setsecurity(d_inode(dentry), entry->fattr, entry->label); |
|
goto out; |
|
} else { |
|
d_invalidate(dentry); |
|
dput(dentry); |
|
dentry = NULL; |
|
goto again; |
|
} |
|
} |
|
if (!entry->fh->size) { |
|
d_lookup_done(dentry); |
|
goto out; |
|
} |
|
|
|
inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr, entry->label); |
|
alias = d_splice_alias(inode, dentry); |
|
d_lookup_done(dentry); |
|
if (alias) { |
|
if (IS_ERR(alias)) |
|
goto out; |
|
dput(dentry); |
|
dentry = alias; |
|
} |
|
nfs_set_verifier(dentry, dir_verifier); |
|
out: |
|
dput(dentry); |
|
} |
|
|
|
/* Perform conversion from xdr to cache array */ |
|
static |
|
int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry, |
|
struct page **xdr_pages, struct page *page, unsigned int buflen) |
|
{ |
|
struct xdr_stream stream; |
|
struct xdr_buf buf; |
|
struct page *scratch; |
|
struct nfs_cache_array *array; |
|
unsigned int count = 0; |
|
int status; |
|
|
|
scratch = alloc_page(GFP_KERNEL); |
|
if (scratch == NULL) |
|
return -ENOMEM; |
|
|
|
if (buflen == 0) |
|
goto out_nopages; |
|
|
|
xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen); |
|
xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE); |
|
|
|
do { |
|
if (entry->label) |
|
entry->label->len = NFS4_MAXLABELLEN; |
|
|
|
status = xdr_decode(desc, entry, &stream); |
|
if (status != 0) { |
|
if (status == -EAGAIN) |
|
status = 0; |
|
break; |
|
} |
|
|
|
count++; |
|
|
|
if (desc->plus) |
|
nfs_prime_dcache(file_dentry(desc->file), entry, |
|
desc->dir_verifier); |
|
|
|
status = nfs_readdir_add_to_array(entry, page); |
|
if (status != 0) |
|
break; |
|
} while (!entry->eof); |
|
|
|
out_nopages: |
|
if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) { |
|
array = kmap(page); |
|
array->eof_index = array->size; |
|
status = 0; |
|
kunmap(page); |
|
} |
|
|
|
put_page(scratch); |
|
return status; |
|
} |
|
|
|
static |
|
void nfs_readdir_free_pages(struct page **pages, unsigned int npages) |
|
{ |
|
unsigned int i; |
|
for (i = 0; i < npages; i++) |
|
put_page(pages[i]); |
|
} |
|
|
|
/* |
|
* nfs_readdir_alloc_pages() will allocate pages that must be freed with a call |
|
* to nfs_readdir_free_pages() |
|
*/ |
|
static |
|
int nfs_readdir_alloc_pages(struct page **pages, unsigned int npages) |
|
{ |
|
unsigned int i; |
|
|
|
for (i = 0; i < npages; i++) { |
|
struct page *page = alloc_page(GFP_KERNEL); |
|
if (page == NULL) |
|
goto out_freepages; |
|
pages[i] = page; |
|
} |
|
return 0; |
|
|
|
out_freepages: |
|
nfs_readdir_free_pages(pages, i); |
|
return -ENOMEM; |
|
} |
|
|
|
static |
|
int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode) |
|
{ |
|
struct page *pages[NFS_MAX_READDIR_PAGES]; |
|
struct nfs_entry entry; |
|
struct file *file = desc->file; |
|
struct nfs_cache_array *array; |
|
int status = -ENOMEM; |
|
unsigned int array_size = ARRAY_SIZE(pages); |
|
|
|
nfs_readdir_init_array(page); |
|
|
|
entry.prev_cookie = 0; |
|
entry.cookie = desc->last_cookie; |
|
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) |
|
goto out; |
|
|
|
entry.label = nfs4_label_alloc(NFS_SERVER(inode), GFP_NOWAIT); |
|
if (IS_ERR(entry.label)) { |
|
status = PTR_ERR(entry.label); |
|
goto out; |
|
} |
|
|
|
array = kmap(page); |
|
|
|
status = nfs_readdir_alloc_pages(pages, array_size); |
|
if (status < 0) |
|
goto out_release_array; |
|
do { |
|
unsigned int pglen; |
|
status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode); |
|
|
|
if (status < 0) |
|
break; |
|
pglen = status; |
|
status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen); |
|
if (status < 0) { |
|
if (status == -ENOSPC) |
|
status = 0; |
|
break; |
|
} |
|
} while (array->eof_index < 0); |
|
|
|
nfs_readdir_free_pages(pages, array_size); |
|
out_release_array: |
|
kunmap(page); |
|
nfs4_label_free(entry.label); |
|
out: |
|
nfs_free_fattr(entry.fattr); |
|
nfs_free_fhandle(entry.fh); |
|
return status; |
|
} |
|
|
|
/* |
|
* Now we cache directories properly, by converting xdr information |
|
* to an array that can be used for lookups later. This results in |
|
* fewer cache pages, since we can store more information on each page. |
|
* We only need to convert from xdr once so future lookups are much simpler |
|
*/ |
|
static |
|
int nfs_readdir_filler(void *data, struct page* page) |
|
{ |
|
nfs_readdir_descriptor_t *desc = data; |
|
struct inode *inode = file_inode(desc->file); |
|
int ret; |
|
|
|
ret = nfs_readdir_xdr_to_array(desc, page, inode); |
|
if (ret < 0) |
|
goto error; |
|
SetPageUptodate(page); |
|
|
|
if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) { |
|
/* Should never happen */ |
|
nfs_zap_mapping(inode, inode->i_mapping); |
|
} |
|
unlock_page(page); |
|
return 0; |
|
error: |
|
nfs_readdir_clear_array(page); |
|
unlock_page(page); |
|
return ret; |
|
} |
|
|
|
static |
|
void cache_page_release(nfs_readdir_descriptor_t *desc) |
|
{ |
|
put_page(desc->page); |
|
desc->page = NULL; |
|
} |
|
|
|
static |
|
struct page *get_cache_page(nfs_readdir_descriptor_t *desc) |
|
{ |
|
return read_cache_page(desc->file->f_mapping, desc->page_index, |
|
nfs_readdir_filler, 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) |
|
{ |
|
struct inode *inode = file_inode(desc->file); |
|
struct nfs_inode *nfsi = NFS_I(inode); |
|
int res; |
|
|
|
desc->page = get_cache_page(desc); |
|
if (IS_ERR(desc->page)) |
|
return PTR_ERR(desc->page); |
|
res = lock_page_killable(desc->page); |
|
if (res != 0) |
|
goto error; |
|
res = -EAGAIN; |
|
if (desc->page->mapping != NULL) { |
|
res = nfs_readdir_search_array(desc); |
|
if (res == 0) { |
|
nfsi->page_index = desc->page_index; |
|
return 0; |
|
} |
|
} |
|
unlock_page(desc->page); |
|
error: |
|
cache_page_release(desc); |
|
return res; |
|
} |
|
|
|
/* Search for desc->dir_cookie from the beginning of the page cache */ |
|
static inline |
|
int readdir_search_pagecache(nfs_readdir_descriptor_t *desc) |
|
{ |
|
int res; |
|
|
|
if (desc->page_index == 0) { |
|
desc->current_index = 0; |
|
desc->prev_index = 0; |
|
desc->last_cookie = 0; |
|
} |
|
do { |
|
res = find_and_lock_cache_page(desc); |
|
} while (res == -EAGAIN); |
|
return res; |
|
} |
|
|
|
/* |
|
* Once we've found the start of the dirent within a page: fill 'er up... |
|
*/ |
|
static |
|
int nfs_do_filldir(nfs_readdir_descriptor_t *desc) |
|
{ |
|
struct file *file = desc->file; |
|
int i = 0; |
|
int res = 0; |
|
struct nfs_cache_array *array = NULL; |
|
struct nfs_open_dir_context *ctx = file->private_data; |
|
|
|
array = kmap(desc->page); |
|
for (i = desc->cache_entry_index; i < array->size; i++) { |
|
struct nfs_cache_array_entry *ent; |
|
|
|
ent = &array->array[i]; |
|
if (!dir_emit(desc->ctx, ent->string.name, ent->string.len, |
|
nfs_compat_user_ino64(ent->ino), ent->d_type)) { |
|
desc->eof = true; |
|
break; |
|
} |
|
if (i < (array->size-1)) |
|
*desc->dir_cookie = array->array[i+1].cookie; |
|
else |
|
*desc->dir_cookie = array->last_cookie; |
|
if (nfs_readdir_use_cookie(file)) |
|
desc->ctx->pos = *desc->dir_cookie; |
|
else |
|
desc->ctx->pos++; |
|
if (ctx->duped != 0) |
|
ctx->duped = 1; |
|
} |
|
if (array->eof_index >= 0) |
|
desc->eof = true; |
|
|
|
kunmap(desc->page); |
|
dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n", |
|
(unsigned long long)*desc->dir_cookie, res); |
|
return res; |
|
} |
|
|
|
/* |
|
* If we cannot find a cookie in our cache, we suspect that this is |
|
* because it points to a deleted file, so we ask the server to return |
|
* whatever it thinks is the next entry. We then feed this to filldir. |
|
* If all goes well, we should then be able to find our way round the |
|
* cache on the next call to readdir_search_pagecache(); |
|
* |
|
* NOTE: we cannot add the anonymous page to the pagecache because |
|
* the data it contains might not be page aligned. Besides, |
|
* 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) |
|
{ |
|
struct page *page = NULL; |
|
int status; |
|
struct inode *inode = file_inode(desc->file); |
|
struct nfs_open_dir_context *ctx = desc->file->private_data; |
|
|
|
dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n", |
|
(unsigned long long)*desc->dir_cookie); |
|
|
|
page = alloc_page(GFP_HIGHUSER); |
|
if (!page) { |
|
status = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
desc->page_index = 0; |
|
desc->last_cookie = *desc->dir_cookie; |
|
desc->page = page; |
|
ctx->duped = 0; |
|
|
|
status = nfs_readdir_xdr_to_array(desc, page, inode); |
|
if (status < 0) |
|
goto out_release; |
|
|
|
status = nfs_do_filldir(desc); |
|
|
|
out_release: |
|
nfs_readdir_clear_array(desc->page); |
|
cache_page_release(desc); |
|
out: |
|
dfprintk(DIRCACHE, "NFS: %s: returns %d\n", |
|
__func__, status); |
|
return status; |
|
} |
|
|
|
/* The file offset position represents the dirent entry number. A |
|
last cookie cache takes care of the common case of reading the |
|
whole directory. |
|
*/ |
|
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, |
|
.dir_cookie = &dir_ctx->dir_cookie, |
|
.plus = nfs_use_readdirplus(inode, ctx), |
|
}, |
|
*desc = &my_desc; |
|
int res = 0; |
|
|
|
dfprintk(FILE, "NFS: readdir(%pD2) starting at cookie %llu\n", |
|
file, (long long)ctx->pos); |
|
nfs_inc_stats(inode, NFSIOS_VFSGETDENTS); |
|
|
|
/* |
|
* ctx->pos points to the dirent entry number. |
|
* *desc->dir_cookie has the cookie for the next entry. We have |
|
* to either find the entry with the appropriate number or |
|
* revalidate the cookie. |
|
*/ |
|
if (ctx->pos == 0 || nfs_attribute_cache_expired(inode)) |
|
res = nfs_revalidate_mapping(inode, file->f_mapping); |
|
if (res < 0) |
|
goto out; |
|
|
|
do { |
|
res = readdir_search_pagecache(desc); |
|
|
|
if (res == -EBADCOOKIE) { |
|
res = 0; |
|
/* This means either end of directory */ |
|
if (*desc->dir_cookie && !desc->eof) { |
|
/* Or that the server has 'lost' a cookie */ |
|
res = uncached_readdir(desc); |
|
if (res == 0) |
|
continue; |
|
} |
|
break; |
|
} |
|
if (res == -ETOOSMALL && desc->plus) { |
|
clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags); |
|
nfs_zap_caches(inode); |
|
desc->page_index = 0; |
|
desc->plus = false; |
|
desc->eof = false; |
|
continue; |
|
} |
|
if (res < 0) |
|
break; |
|
|
|
res = nfs_do_filldir(desc); |
|
unlock_page(desc->page); |
|
cache_page_release(desc); |
|
if (res < 0) |
|
break; |
|
} while (!desc->eof); |
|
out: |
|
if (res > 0) |
|
res = 0; |
|
dfprintk(FILE, "NFS: readdir(%pD2) returns %d\n", file, res); |
|
return res; |
|
} |
|
|
|
static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence) |
|
{ |
|
struct nfs_open_dir_context *dir_ctx = filp->private_data; |
|
|
|
dfprintk(FILE, "NFS: llseek dir(%pD2, %lld, %d)\n", |
|
filp, offset, whence); |
|
|
|
switch (whence) { |
|
default: |
|
return -EINVAL; |
|
case SEEK_SET: |
|
if (offset < 0) |
|
return -EINVAL; |
|
spin_lock(&filp->f_lock); |
|
break; |
|
case SEEK_CUR: |
|
if (offset == 0) |
|
return filp->f_pos; |
|
spin_lock(&filp->f_lock); |
|
offset += filp->f_pos; |
|
if (offset < 0) { |
|
spin_unlock(&filp->f_lock); |
|
return -EINVAL; |
|
} |
|
} |
|
if (offset != filp->f_pos) { |
|
filp->f_pos = offset; |
|
if (nfs_readdir_use_cookie(filp)) |
|
dir_ctx->dir_cookie = offset; |
|
else |
|
dir_ctx->dir_cookie = 0; |
|
dir_ctx->duped = 0; |
|
} |
|
spin_unlock(&filp->f_lock); |
|
return offset; |
|
} |
|
|
|
/* |
|
* All directory operations under NFS are synchronous, so fsync() |
|
* is a dummy operation. |
|
*/ |
|
static int nfs_fsync_dir(struct file *filp, loff_t start, loff_t end, |
|
int datasync) |
|
{ |
|
dfprintk(FILE, "NFS: fsync dir(%pD2) datasync %d\n", filp, datasync); |
|
|
|
nfs_inc_stats(file_inode(filp), NFSIOS_VFSFSYNC); |
|
return 0; |
|
} |
|
|
|
/** |
|
* nfs_force_lookup_revalidate - Mark the directory as having changed |
|
* @dir: pointer to directory inode |
|
* |
|
* This forces the revalidation code in nfs_lookup_revalidate() to do a |
|
* full lookup on all child dentries of 'dir' whenever a change occurs |
|
* on the server that might have invalidated our dcache. |
|
* |
|
* Note that we reserve bit '0' as a tag to let us know when a dentry |
|
* was revalidated while holding a delegation on its inode. |
|
* |
|
* The caller should be holding dir->i_lock |
|
*/ |
|
void nfs_force_lookup_revalidate(struct inode *dir) |
|
{ |
|
NFS_I(dir)->cache_change_attribute += 2; |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_force_lookup_revalidate); |
|
|
|
/** |
|
* nfs_verify_change_attribute - Detects NFS remote directory changes |
|
* @dir: pointer to parent directory inode |
|
* @verf: previously saved change attribute |
|
* |
|
* Return "false" if the verifiers doesn't match the change attribute. |
|
* This would usually indicate that the directory contents have changed on |
|
* the server, and that any dentries need revalidating. |
|
*/ |
|
static bool nfs_verify_change_attribute(struct inode *dir, unsigned long verf) |
|
{ |
|
return (verf & ~1UL) == nfs_save_change_attribute(dir); |
|
} |
|
|
|
static void nfs_set_verifier_delegated(unsigned long *verf) |
|
{ |
|
*verf |= 1UL; |
|
} |
|
|
|
#if IS_ENABLED(CONFIG_NFS_V4) |
|
static void nfs_unset_verifier_delegated(unsigned long *verf) |
|
{ |
|
*verf &= ~1UL; |
|
} |
|
#endif /* IS_ENABLED(CONFIG_NFS_V4) */ |
|
|
|
static bool nfs_test_verifier_delegated(unsigned long verf) |
|
{ |
|
return verf & 1; |
|
} |
|
|
|
static bool nfs_verifier_is_delegated(struct dentry *dentry) |
|
{ |
|
return nfs_test_verifier_delegated(dentry->d_time); |
|
} |
|
|
|
static void nfs_set_verifier_locked(struct dentry *dentry, unsigned long verf) |
|
{ |
|
struct inode *inode = d_inode(dentry); |
|
|
|
if (!nfs_verifier_is_delegated(dentry) && |
|
!nfs_verify_change_attribute(d_inode(dentry->d_parent), verf)) |
|
goto out; |
|
if (inode && NFS_PROTO(inode)->have_delegation(inode, FMODE_READ)) |
|
nfs_set_verifier_delegated(&verf); |
|
out: |
|
dentry->d_time = verf; |
|
} |
|
|
|
/** |
|
* nfs_set_verifier - save a parent directory verifier in the dentry |
|
* @dentry: pointer to dentry |
|
* @verf: verifier to save |
|
* |
|
* Saves the parent directory verifier in @dentry. If the inode has |
|
* a delegation, we also tag the dentry as having been revalidated |
|
* while holding a delegation so that we know we don't have to |
|
* look it up again after a directory change. |
|
*/ |
|
void nfs_set_verifier(struct dentry *dentry, unsigned long verf) |
|
{ |
|
|
|
spin_lock(&dentry->d_lock); |
|
nfs_set_verifier_locked(dentry, verf); |
|
spin_unlock(&dentry->d_lock); |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_set_verifier); |
|
|
|
#if IS_ENABLED(CONFIG_NFS_V4) |
|
/** |
|
* nfs_clear_verifier_delegated - clear the dir verifier delegation tag |
|
* @inode: pointer to inode |
|
* |
|
* Iterates through the dentries in the inode alias list and clears |
|
* the tag used to indicate that the dentry has been revalidated |
|
* while holding a delegation. |
|
* This function is intended for use when the delegation is being |
|
* returned or revoked. |
|
*/ |
|
void nfs_clear_verifier_delegated(struct inode *inode) |
|
{ |
|
struct dentry *alias; |
|
|
|
if (!inode) |
|
return; |
|
spin_lock(&inode->i_lock); |
|
hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) { |
|
spin_lock(&alias->d_lock); |
|
nfs_unset_verifier_delegated(&alias->d_time); |
|
spin_unlock(&alias->d_lock); |
|
} |
|
spin_unlock(&inode->i_lock); |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_clear_verifier_delegated); |
|
#endif /* IS_ENABLED(CONFIG_NFS_V4) */ |
|
|
|
/* |
|
* A check for whether or not the parent directory has changed. |
|
* In the case it has, we assume that the dentries are untrustworthy |
|
* and may need to be looked up again. |
|
* If rcu_walk prevents us from performing a full check, return 0. |
|
*/ |
|
static int nfs_check_verifier(struct inode *dir, struct dentry *dentry, |
|
int rcu_walk) |
|
{ |
|
if (IS_ROOT(dentry)) |
|
return 1; |
|
if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE) |
|
return 0; |
|
if (!nfs_verify_change_attribute(dir, dentry->d_time)) |
|
return 0; |
|
/* Revalidate nfsi->cache_change_attribute before we declare a match */ |
|
if (nfs_mapping_need_revalidate_inode(dir)) { |
|
if (rcu_walk) |
|
return 0; |
|
if (__nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0) |
|
return 0; |
|
} |
|
if (!nfs_verify_change_attribute(dir, dentry->d_time)) |
|
return 0; |
|
return 1; |
|
} |
|
|
|
/* |
|
* Use intent information to check whether or not we're going to do |
|
* an O_EXCL create using this path component. |
|
*/ |
|
static int nfs_is_exclusive_create(struct inode *dir, unsigned int flags) |
|
{ |
|
if (NFS_PROTO(dir)->version == 2) |
|
return 0; |
|
return flags & LOOKUP_EXCL; |
|
} |
|
|
|
/* |
|
* Inode and filehandle revalidation for lookups. |
|
* |
|
* We force revalidation in the cases where the VFS sets LOOKUP_REVAL, |
|
* or if the intent information indicates that we're about to open this |
|
* particular file and the "nocto" mount flag is not set. |
|
* |
|
*/ |
|
static |
|
int nfs_lookup_verify_inode(struct inode *inode, unsigned int flags) |
|
{ |
|
struct nfs_server *server = NFS_SERVER(inode); |
|
int ret; |
|
|
|
if (IS_AUTOMOUNT(inode)) |
|
return 0; |
|
|
|
if (flags & LOOKUP_OPEN) { |
|
switch (inode->i_mode & S_IFMT) { |
|
case S_IFREG: |
|
/* A NFSv4 OPEN will revalidate later */ |
|
if (server->caps & NFS_CAP_ATOMIC_OPEN) |
|
goto out; |
|
fallthrough; |
|
case S_IFDIR: |
|
if (server->flags & NFS_MOUNT_NOCTO) |
|
break; |
|
/* NFS close-to-open cache consistency validation */ |
|
goto out_force; |
|
} |
|
} |
|
|
|
/* VFS wants an on-the-wire revalidation */ |
|
if (flags & LOOKUP_REVAL) |
|
goto out_force; |
|
out: |
|
return (inode->i_nlink == 0) ? -ESTALE : 0; |
|
out_force: |
|
if (flags & LOOKUP_RCU) |
|
return -ECHILD; |
|
ret = __nfs_revalidate_inode(server, inode); |
|
if (ret != 0) |
|
return ret; |
|
goto out; |
|
} |
|
|
|
static void nfs_mark_dir_for_revalidate(struct inode *inode) |
|
{ |
|
struct nfs_inode *nfsi = NFS_I(inode); |
|
|
|
spin_lock(&inode->i_lock); |
|
nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE; |
|
spin_unlock(&inode->i_lock); |
|
} |
|
|
|
/* |
|
* We judge how long we want to trust negative |
|
* dentries by looking at the parent inode mtime. |
|
* |
|
* If parent mtime has changed, we revalidate, else we wait for a |
|
* period corresponding to the parent's attribute cache timeout value. |
|
* |
|
* If LOOKUP_RCU prevents us from performing a full check, return 1 |
|
* suggesting a reval is needed. |
|
* |
|
* Note that when creating a new file, or looking up a rename target, |
|
* then it shouldn't be necessary to revalidate a negative dentry. |
|
*/ |
|
static inline |
|
int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry, |
|
unsigned int flags) |
|
{ |
|
if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET)) |
|
return 0; |
|
if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) |
|
return 1; |
|
return !nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU); |
|
} |
|
|
|
static int |
|
nfs_lookup_revalidate_done(struct inode *dir, struct dentry *dentry, |
|
struct inode *inode, int error) |
|
{ |
|
switch (error) { |
|
case 1: |
|
dfprintk(LOOKUPCACHE, "NFS: %s(%pd2) is valid\n", |
|
__func__, dentry); |
|
return 1; |
|
case 0: |
|
/* |
|
* We can't d_drop the root of a disconnected tree: |
|
* its d_hash is on the s_anon list and d_drop() would hide |
|
* it from shrink_dcache_for_unmount(), leading to busy |
|
* inodes on unmount and further oopses. |
|
*/ |
|
if (inode && IS_ROOT(dentry)) |
|
return 1; |
|
dfprintk(LOOKUPCACHE, "NFS: %s(%pd2) is invalid\n", |
|
__func__, dentry); |
|
return 0; |
|
} |
|
dfprintk(LOOKUPCACHE, "NFS: %s(%pd2) lookup returned error %d\n", |
|
__func__, dentry, error); |
|
return error; |
|
} |
|
|
|
static int |
|
nfs_lookup_revalidate_negative(struct inode *dir, struct dentry *dentry, |
|
unsigned int flags) |
|
{ |
|
int ret = 1; |
|
if (nfs_neg_need_reval(dir, dentry, flags)) { |
|
if (flags & LOOKUP_RCU) |
|
return -ECHILD; |
|
ret = 0; |
|
} |
|
return nfs_lookup_revalidate_done(dir, dentry, NULL, ret); |
|
} |
|
|
|
static int |
|
nfs_lookup_revalidate_delegated(struct inode *dir, struct dentry *dentry, |
|
struct inode *inode) |
|
{ |
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
|
return nfs_lookup_revalidate_done(dir, dentry, inode, 1); |
|
} |
|
|
|
static int |
|
nfs_lookup_revalidate_dentry(struct inode *dir, struct dentry *dentry, |
|
struct inode *inode) |
|
{ |
|
struct nfs_fh *fhandle; |
|
struct nfs_fattr *fattr; |
|
struct nfs4_label *label; |
|
unsigned long dir_verifier; |
|
int ret; |
|
|
|
ret = -ENOMEM; |
|
fhandle = nfs_alloc_fhandle(); |
|
fattr = nfs_alloc_fattr(); |
|
label = nfs4_label_alloc(NFS_SERVER(inode), GFP_KERNEL); |
|
if (fhandle == NULL || fattr == NULL || IS_ERR(label)) |
|
goto out; |
|
|
|
dir_verifier = nfs_save_change_attribute(dir); |
|
ret = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr, label); |
|
if (ret < 0) { |
|
switch (ret) { |
|
case -ESTALE: |
|
case -ENOENT: |
|
ret = 0; |
|
break; |
|
case -ETIMEDOUT: |
|
if (NFS_SERVER(inode)->flags & NFS_MOUNT_SOFTREVAL) |
|
ret = 1; |
|
} |
|
goto out; |
|
} |
|
ret = 0; |
|
if (nfs_compare_fh(NFS_FH(inode), fhandle)) |
|
goto out; |
|
if (nfs_refresh_inode(inode, fattr) < 0) |
|
goto out; |
|
|
|
nfs_setsecurity(inode, fattr, label); |
|
nfs_set_verifier(dentry, dir_verifier); |
|
|
|
/* set a readdirplus hint that we had a cache miss */ |
|
nfs_force_use_readdirplus(dir); |
|
ret = 1; |
|
out: |
|
nfs_free_fattr(fattr); |
|
nfs_free_fhandle(fhandle); |
|
nfs4_label_free(label); |
|
|
|
/* |
|
* If the lookup failed despite the dentry change attribute being |
|
* a match, then we should revalidate the directory cache. |
|
*/ |
|
if (!ret && nfs_verify_change_attribute(dir, dentry->d_time)) |
|
nfs_mark_dir_for_revalidate(dir); |
|
return nfs_lookup_revalidate_done(dir, dentry, inode, ret); |
|
} |
|
|
|
/* |
|
* This is called every time the dcache has a lookup hit, |
|
* and we should check whether we can really trust that |
|
* lookup. |
|
* |
|
* NOTE! The hit can be a negative hit too, don't assume |
|
* we have an inode! |
|
* |
|
* If the parent directory is seen to have changed, we throw out the |
|
* cached dentry and do a new lookup. |
|
*/ |
|
static int |
|
nfs_do_lookup_revalidate(struct inode *dir, struct dentry *dentry, |
|
unsigned int flags) |
|
{ |
|
struct inode *inode; |
|
int error; |
|
|
|
nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE); |
|
inode = d_inode(dentry); |
|
|
|
if (!inode) |
|
return nfs_lookup_revalidate_negative(dir, dentry, flags); |
|
|
|
if (is_bad_inode(inode)) { |
|
dfprintk(LOOKUPCACHE, "%s: %pd2 has dud inode\n", |
|
__func__, dentry); |
|
goto out_bad; |
|
} |
|
|
|
if (nfs_verifier_is_delegated(dentry)) |
|
return nfs_lookup_revalidate_delegated(dir, dentry, inode); |
|
|
|
/* Force a full look up iff the parent directory has changed */ |
|
if (!(flags & (LOOKUP_EXCL | LOOKUP_REVAL)) && |
|
nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU)) { |
|
error = nfs_lookup_verify_inode(inode, flags); |
|
if (error) { |
|
if (error == -ESTALE) |
|
nfs_mark_dir_for_revalidate(dir); |
|
goto out_bad; |
|
} |
|
nfs_advise_use_readdirplus(dir); |
|
goto out_valid; |
|
} |
|
|
|
if (flags & LOOKUP_RCU) |
|
return -ECHILD; |
|
|
|
if (NFS_STALE(inode)) |
|
goto out_bad; |
|
|
|
trace_nfs_lookup_revalidate_enter(dir, dentry, flags); |
|
error = nfs_lookup_revalidate_dentry(dir, dentry, inode); |
|
trace_nfs_lookup_revalidate_exit(dir, dentry, flags, error); |
|
return error; |
|
out_valid: |
|
return nfs_lookup_revalidate_done(dir, dentry, inode, 1); |
|
out_bad: |
|
if (flags & LOOKUP_RCU) |
|
return -ECHILD; |
|
return nfs_lookup_revalidate_done(dir, dentry, inode, 0); |
|
} |
|
|
|
static int |
|
__nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags, |
|
int (*reval)(struct inode *, struct dentry *, unsigned int)) |
|
{ |
|
struct dentry *parent; |
|
struct inode *dir; |
|
int ret; |
|
|
|
if (flags & LOOKUP_RCU) { |
|
parent = READ_ONCE(dentry->d_parent); |
|
dir = d_inode_rcu(parent); |
|
if (!dir) |
|
return -ECHILD; |
|
ret = reval(dir, dentry, flags); |
|
if (parent != READ_ONCE(dentry->d_parent)) |
|
return -ECHILD; |
|
} else { |
|
parent = dget_parent(dentry); |
|
ret = reval(d_inode(parent), dentry, flags); |
|
dput(parent); |
|
} |
|
return ret; |
|
} |
|
|
|
static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags) |
|
{ |
|
return __nfs_lookup_revalidate(dentry, flags, nfs_do_lookup_revalidate); |
|
} |
|
|
|
/* |
|
* A weaker form of d_revalidate for revalidating just the d_inode(dentry) |
|
* when we don't really care about the dentry name. This is called when a |
|
* pathwalk ends on a dentry that was not found via a normal lookup in the |
|
* parent dir (e.g.: ".", "..", procfs symlinks or mountpoint traversals). |
|
* |
|
* In this situation, we just want to verify that the inode itself is OK |
|
* since the dentry might have changed on the server. |
|
*/ |
|
static int nfs_weak_revalidate(struct dentry *dentry, unsigned int flags) |
|
{ |
|
struct inode *inode = d_inode(dentry); |
|
int error = 0; |
|
|
|
/* |
|
* I believe we can only get a negative dentry here in the case of a |
|
* procfs-style symlink. Just assume it's correct for now, but we may |
|
* eventually need to do something more here. |
|
*/ |
|
if (!inode) { |
|
dfprintk(LOOKUPCACHE, "%s: %pd2 has negative inode\n", |
|
__func__, dentry); |
|
return 1; |
|
} |
|
|
|
if (is_bad_inode(inode)) { |
|
dfprintk(LOOKUPCACHE, "%s: %pd2 has dud inode\n", |
|
__func__, dentry); |
|
return 0; |
|
} |
|
|
|
error = nfs_lookup_verify_inode(inode, flags); |
|
dfprintk(LOOKUPCACHE, "NFS: %s: inode %lu is %s\n", |
|
__func__, inode->i_ino, error ? "invalid" : "valid"); |
|
return !error; |
|
} |
|
|
|
/* |
|
* This is called from dput() when d_count is going to 0. |
|
*/ |
|
static int nfs_dentry_delete(const struct dentry *dentry) |
|
{ |
|
dfprintk(VFS, "NFS: dentry_delete(%pd2, %x)\n", |
|
dentry, dentry->d_flags); |
|
|
|
/* Unhash any dentry with a stale inode */ |
|
if (d_really_is_positive(dentry) && NFS_STALE(d_inode(dentry))) |
|
return 1; |
|
|
|
if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { |
|
/* Unhash it, so that ->d_iput() would be called */ |
|
return 1; |
|
} |
|
if (!(dentry->d_sb->s_flags & SB_ACTIVE)) { |
|
/* Unhash it, so that ancestors of killed async unlink |
|
* files will be cleaned up during umount */ |
|
return 1; |
|
} |
|
return 0; |
|
|
|
} |
|
|
|
/* Ensure that we revalidate inode->i_nlink */ |
|
static void nfs_drop_nlink(struct inode *inode) |
|
{ |
|
spin_lock(&inode->i_lock); |
|
/* drop the inode if we're reasonably sure this is the last link */ |
|
if (inode->i_nlink > 0) |
|
drop_nlink(inode); |
|
NFS_I(inode)->attr_gencount = nfs_inc_attr_generation_counter(); |
|
NFS_I(inode)->cache_validity |= NFS_INO_INVALID_CHANGE |
|
| NFS_INO_INVALID_CTIME |
|
| NFS_INO_INVALID_OTHER |
|
| NFS_INO_REVAL_FORCED; |
|
spin_unlock(&inode->i_lock); |
|
} |
|
|
|
/* |
|
* Called when the dentry loses inode. |
|
* We use it to clean up silly-renamed files. |
|
*/ |
|
static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode) |
|
{ |
|
if (S_ISDIR(inode->i_mode)) |
|
/* drop any readdir cache as it could easily be old */ |
|
NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA; |
|
|
|
if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { |
|
nfs_complete_unlink(dentry, inode); |
|
nfs_drop_nlink(inode); |
|
} |
|
iput(inode); |
|
} |
|
|
|
static void nfs_d_release(struct dentry *dentry) |
|
{ |
|
/* free cached devname value, if it survived that far */ |
|
if (unlikely(dentry->d_fsdata)) { |
|
if (dentry->d_flags & DCACHE_NFSFS_RENAMED) |
|
WARN_ON(1); |
|
else |
|
kfree(dentry->d_fsdata); |
|
} |
|
} |
|
|
|
const struct dentry_operations nfs_dentry_operations = { |
|
.d_revalidate = nfs_lookup_revalidate, |
|
.d_weak_revalidate = nfs_weak_revalidate, |
|
.d_delete = nfs_dentry_delete, |
|
.d_iput = nfs_dentry_iput, |
|
.d_automount = nfs_d_automount, |
|
.d_release = nfs_d_release, |
|
}; |
|
EXPORT_SYMBOL_GPL(nfs_dentry_operations); |
|
|
|
struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) |
|
{ |
|
struct dentry *res; |
|
struct inode *inode = NULL; |
|
struct nfs_fh *fhandle = NULL; |
|
struct nfs_fattr *fattr = NULL; |
|
struct nfs4_label *label = NULL; |
|
unsigned long dir_verifier; |
|
int error; |
|
|
|
dfprintk(VFS, "NFS: lookup(%pd2)\n", dentry); |
|
nfs_inc_stats(dir, NFSIOS_VFSLOOKUP); |
|
|
|
if (unlikely(dentry->d_name.len > NFS_SERVER(dir)->namelen)) |
|
return ERR_PTR(-ENAMETOOLONG); |
|
|
|
/* |
|
* If we're doing an exclusive create, optimize away the lookup |
|
* but don't hash the dentry. |
|
*/ |
|
if (nfs_is_exclusive_create(dir, flags) || flags & LOOKUP_RENAME_TARGET) |
|
return NULL; |
|
|
|
res = ERR_PTR(-ENOMEM); |
|
fhandle = nfs_alloc_fhandle(); |
|
fattr = nfs_alloc_fattr(); |
|
if (fhandle == NULL || fattr == NULL) |
|
goto out; |
|
|
|
label = nfs4_label_alloc(NFS_SERVER(dir), GFP_NOWAIT); |
|
if (IS_ERR(label)) |
|
goto out; |
|
|
|
dir_verifier = nfs_save_change_attribute(dir); |
|
trace_nfs_lookup_enter(dir, dentry, flags); |
|
error = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr, label); |
|
if (error == -ENOENT) |
|
goto no_entry; |
|
if (error < 0) { |
|
res = ERR_PTR(error); |
|
goto out_label; |
|
} |
|
inode = nfs_fhget(dentry->d_sb, fhandle, fattr, label); |
|
res = ERR_CAST(inode); |
|
if (IS_ERR(res)) |
|
goto out_label; |
|
|
|
/* Notify readdir to use READDIRPLUS */ |
|
nfs_force_use_readdirplus(dir); |
|
|
|
no_entry: |
|
res = d_splice_alias(inode, dentry); |
|
if (res != NULL) { |
|
if (IS_ERR(res)) |
|
goto out_label; |
|
dentry = res; |
|
} |
|
nfs_set_verifier(dentry, dir_verifier); |
|
out_label: |
|
trace_nfs_lookup_exit(dir, dentry, flags, error); |
|
nfs4_label_free(label); |
|
out: |
|
nfs_free_fattr(fattr); |
|
nfs_free_fhandle(fhandle); |
|
return res; |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_lookup); |
|
|
|
#if IS_ENABLED(CONFIG_NFS_V4) |
|
static int nfs4_lookup_revalidate(struct dentry *, unsigned int); |
|
|
|
const struct dentry_operations nfs4_dentry_operations = { |
|
.d_revalidate = nfs4_lookup_revalidate, |
|
.d_weak_revalidate = nfs_weak_revalidate, |
|
.d_delete = nfs_dentry_delete, |
|
.d_iput = nfs_dentry_iput, |
|
.d_automount = nfs_d_automount, |
|
.d_release = nfs_d_release, |
|
}; |
|
EXPORT_SYMBOL_GPL(nfs4_dentry_operations); |
|
|
|
static fmode_t flags_to_mode(int flags) |
|
{ |
|
fmode_t res = (__force fmode_t)flags & FMODE_EXEC; |
|
if ((flags & O_ACCMODE) != O_WRONLY) |
|
res |= FMODE_READ; |
|
if ((flags & O_ACCMODE) != O_RDONLY) |
|
res |= FMODE_WRITE; |
|
return res; |
|
} |
|
|
|
static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags, struct file *filp) |
|
{ |
|
return alloc_nfs_open_context(dentry, flags_to_mode(open_flags), filp); |
|
} |
|
|
|
static int do_open(struct inode *inode, struct file *filp) |
|
{ |
|
nfs_fscache_open_file(inode, filp); |
|
return 0; |
|
} |
|
|
|
static int nfs_finish_open(struct nfs_open_context *ctx, |
|
struct dentry *dentry, |
|
struct file *file, unsigned open_flags) |
|
{ |
|
int err; |
|
|
|
err = finish_open(file, dentry, do_open); |
|
if (err) |
|
goto out; |
|
if (S_ISREG(file->f_path.dentry->d_inode->i_mode)) |
|
nfs_file_set_open_context(file, ctx); |
|
else |
|
err = -EOPENSTALE; |
|
out: |
|
return err; |
|
} |
|
|
|
int nfs_atomic_open(struct inode *dir, struct dentry *dentry, |
|
struct file *file, unsigned open_flags, |
|
umode_t mode) |
|
{ |
|
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); |
|
struct nfs_open_context *ctx; |
|
struct dentry *res; |
|
struct iattr attr = { .ia_valid = ATTR_OPEN }; |
|
struct inode *inode; |
|
unsigned int lookup_flags = 0; |
|
bool switched = false; |
|
int created = 0; |
|
int err; |
|
|
|
/* Expect a negative dentry */ |
|
BUG_ON(d_inode(dentry)); |
|
|
|
dfprintk(VFS, "NFS: atomic_open(%s/%lu), %pd\n", |
|
dir->i_sb->s_id, dir->i_ino, dentry); |
|
|
|
err = nfs_check_flags(open_flags); |
|
if (err) |
|
return err; |
|
|
|
/* NFS only supports OPEN on regular files */ |
|
if ((open_flags & O_DIRECTORY)) { |
|
if (!d_in_lookup(dentry)) { |
|
/* |
|
* Hashed negative dentry with O_DIRECTORY: dentry was |
|
* revalidated and is fine, no need to perform lookup |
|
* again |
|
*/ |
|
return -ENOENT; |
|
} |
|
lookup_flags = LOOKUP_OPEN|LOOKUP_DIRECTORY; |
|
goto no_open; |
|
} |
|
|
|
if (dentry->d_name.len > NFS_SERVER(dir)->namelen) |
|
return -ENAMETOOLONG; |
|
|
|
if (open_flags & O_CREAT) { |
|
struct nfs_server *server = NFS_SERVER(dir); |
|
|
|
if (!(server->attr_bitmask[2] & FATTR4_WORD2_MODE_UMASK)) |
|
mode &= ~current_umask(); |
|
|
|
attr.ia_valid |= ATTR_MODE; |
|
attr.ia_mode = mode; |
|
} |
|
if (open_flags & O_TRUNC) { |
|
attr.ia_valid |= ATTR_SIZE; |
|
attr.ia_size = 0; |
|
} |
|
|
|
if (!(open_flags & O_CREAT) && !d_in_lookup(dentry)) { |
|
d_drop(dentry); |
|
switched = true; |
|
dentry = d_alloc_parallel(dentry->d_parent, |
|
&dentry->d_name, &wq); |
|
if (IS_ERR(dentry)) |
|
return PTR_ERR(dentry); |
|
if (unlikely(!d_in_lookup(dentry))) |
|
return finish_no_open(file, dentry); |
|
} |
|
|
|
ctx = create_nfs_open_context(dentry, open_flags, file); |
|
err = PTR_ERR(ctx); |
|
if (IS_ERR(ctx)) |
|
goto out; |
|
|
|
trace_nfs_atomic_open_enter(dir, ctx, open_flags); |
|
inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr, &created); |
|
if (created) |
|
file->f_mode |= FMODE_CREATED; |
|
if (IS_ERR(inode)) { |
|
err = PTR_ERR(inode); |
|
trace_nfs_atomic_open_exit(dir, ctx, open_flags, err); |
|
put_nfs_open_context(ctx); |
|
d_drop(dentry); |
|
switch (err) { |
|
case -ENOENT: |
|
d_splice_alias(NULL, dentry); |
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
|
break; |
|
case -EISDIR: |
|
case -ENOTDIR: |
|
goto no_open; |
|
case -ELOOP: |
|
if (!(open_flags & O_NOFOLLOW)) |
|
goto no_open; |
|
break; |
|
/* case -EINVAL: */ |
|
default: |
|
break; |
|
} |
|
goto out; |
|
} |
|
|
|
err = nfs_finish_open(ctx, ctx->dentry, file, open_flags); |
|
trace_nfs_atomic_open_exit(dir, ctx, open_flags, err); |
|
put_nfs_open_context(ctx); |
|
out: |
|
if (unlikely(switched)) { |
|
d_lookup_done(dentry); |
|
dput(dentry); |
|
} |
|
return err; |
|
|
|
no_open: |
|
res = nfs_lookup(dir, dentry, lookup_flags); |
|
if (switched) { |
|
d_lookup_done(dentry); |
|
if (!res) |
|
res = dentry; |
|
else |
|
dput(dentry); |
|
} |
|
if (IS_ERR(res)) |
|
return PTR_ERR(res); |
|
return finish_no_open(file, res); |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_atomic_open); |
|
|
|
static int |
|
nfs4_do_lookup_revalidate(struct inode *dir, struct dentry *dentry, |
|
unsigned int flags) |
|
{ |
|
struct inode *inode; |
|
|
|
if (!(flags & LOOKUP_OPEN) || (flags & LOOKUP_DIRECTORY)) |
|
goto full_reval; |
|
if (d_mountpoint(dentry)) |
|
goto full_reval; |
|
|
|
inode = d_inode(dentry); |
|
|
|
/* We can't create new files in nfs_open_revalidate(), so we |
|
* optimize away revalidation of negative dentries. |
|
*/ |
|
if (inode == NULL) |
|
goto full_reval; |
|
|
|
if (nfs_verifier_is_delegated(dentry)) |
|
return nfs_lookup_revalidate_delegated(dir, dentry, inode); |
|
|
|
/* NFS only supports OPEN on regular files */ |
|
if (!S_ISREG(inode->i_mode)) |
|
goto full_reval; |
|
|
|
/* We cannot do exclusive creation on a positive dentry */ |
|
if (flags & (LOOKUP_EXCL | LOOKUP_REVAL)) |
|
goto reval_dentry; |
|
|
|
/* Check if the directory changed */ |
|
if (!nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU)) |
|
goto reval_dentry; |
|
|
|
/* Let f_op->open() actually open (and revalidate) the file */ |
|
return 1; |
|
reval_dentry: |
|
if (flags & LOOKUP_RCU) |
|
return -ECHILD; |
|
return nfs_lookup_revalidate_dentry(dir, dentry, inode); |
|
|
|
full_reval: |
|
return nfs_do_lookup_revalidate(dir, dentry, flags); |
|
} |
|
|
|
static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags) |
|
{ |
|
return __nfs_lookup_revalidate(dentry, flags, |
|
nfs4_do_lookup_revalidate); |
|
} |
|
|
|
#endif /* CONFIG_NFSV4 */ |
|
|
|
struct dentry * |
|
nfs_add_or_obtain(struct dentry *dentry, struct nfs_fh *fhandle, |
|
struct nfs_fattr *fattr, |
|
struct nfs4_label *label) |
|
{ |
|
struct dentry *parent = dget_parent(dentry); |
|
struct inode *dir = d_inode(parent); |
|
struct inode *inode; |
|
struct dentry *d; |
|
int error; |
|
|
|
d_drop(dentry); |
|
|
|
if (fhandle->size == 0) { |
|
error = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr, NULL); |
|
if (error) |
|
goto out_error; |
|
} |
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
|
if (!(fattr->valid & NFS_ATTR_FATTR)) { |
|
struct nfs_server *server = NFS_SB(dentry->d_sb); |
|
error = server->nfs_client->rpc_ops->getattr(server, fhandle, |
|
fattr, NULL, NULL); |
|
if (error < 0) |
|
goto out_error; |
|
} |
|
inode = nfs_fhget(dentry->d_sb, fhandle, fattr, label); |
|
d = d_splice_alias(inode, dentry); |
|
out: |
|
dput(parent); |
|
return d; |
|
out_error: |
|
d = ERR_PTR(error); |
|
goto out; |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_add_or_obtain); |
|
|
|
/* |
|
* Code common to create, mkdir, and mknod. |
|
*/ |
|
int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle, |
|
struct nfs_fattr *fattr, |
|
struct nfs4_label *label) |
|
{ |
|
struct dentry *d; |
|
|
|
d = nfs_add_or_obtain(dentry, fhandle, fattr, label); |
|
if (IS_ERR(d)) |
|
return PTR_ERR(d); |
|
|
|
/* Callers don't care */ |
|
dput(d); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_instantiate); |
|
|
|
/* |
|
* Following a failed create operation, we drop the dentry rather |
|
* than retain a negative dentry. This avoids a problem in the event |
|
* that the operation succeeded on the server, but an error in the |
|
* reply path made it appear to have failed. |
|
*/ |
|
int nfs_create(struct inode *dir, struct dentry *dentry, |
|
umode_t mode, bool excl) |
|
{ |
|
struct iattr attr; |
|
int open_flags = excl ? O_CREAT | O_EXCL : O_CREAT; |
|
int error; |
|
|
|
dfprintk(VFS, "NFS: create(%s/%lu), %pd\n", |
|
dir->i_sb->s_id, dir->i_ino, dentry); |
|
|
|
attr.ia_mode = mode; |
|
attr.ia_valid = ATTR_MODE; |
|
|
|
trace_nfs_create_enter(dir, dentry, open_flags); |
|
error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags); |
|
trace_nfs_create_exit(dir, dentry, open_flags, error); |
|
if (error != 0) |
|
goto out_err; |
|
return 0; |
|
out_err: |
|
d_drop(dentry); |
|
return error; |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_create); |
|
|
|
/* |
|
* See comments for nfs_proc_create regarding failed operations. |
|
*/ |
|
int |
|
nfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev) |
|
{ |
|
struct iattr attr; |
|
int status; |
|
|
|
dfprintk(VFS, "NFS: mknod(%s/%lu), %pd\n", |
|
dir->i_sb->s_id, dir->i_ino, dentry); |
|
|
|
attr.ia_mode = mode; |
|
attr.ia_valid = ATTR_MODE; |
|
|
|
trace_nfs_mknod_enter(dir, dentry); |
|
status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev); |
|
trace_nfs_mknod_exit(dir, dentry, status); |
|
if (status != 0) |
|
goto out_err; |
|
return 0; |
|
out_err: |
|
d_drop(dentry); |
|
return status; |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_mknod); |
|
|
|
/* |
|
* See comments for nfs_proc_create regarding failed operations. |
|
*/ |
|
int nfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) |
|
{ |
|
struct iattr attr; |
|
int error; |
|
|
|
dfprintk(VFS, "NFS: mkdir(%s/%lu), %pd\n", |
|
dir->i_sb->s_id, dir->i_ino, dentry); |
|
|
|
attr.ia_valid = ATTR_MODE; |
|
attr.ia_mode = mode | S_IFDIR; |
|
|
|
trace_nfs_mkdir_enter(dir, dentry); |
|
error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr); |
|
trace_nfs_mkdir_exit(dir, dentry, error); |
|
if (error != 0) |
|
goto out_err; |
|
return 0; |
|
out_err: |
|
d_drop(dentry); |
|
return error; |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_mkdir); |
|
|
|
static void nfs_dentry_handle_enoent(struct dentry *dentry) |
|
{ |
|
if (simple_positive(dentry)) |
|
d_delete(dentry); |
|
} |
|
|
|
int nfs_rmdir(struct inode *dir, struct dentry *dentry) |
|
{ |
|
int error; |
|
|
|
dfprintk(VFS, "NFS: rmdir(%s/%lu), %pd\n", |
|
dir->i_sb->s_id, dir->i_ino, dentry); |
|
|
|
trace_nfs_rmdir_enter(dir, dentry); |
|
if (d_really_is_positive(dentry)) { |
|
down_write(&NFS_I(d_inode(dentry))->rmdir_sem); |
|
error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name); |
|
/* Ensure the VFS deletes this inode */ |
|
switch (error) { |
|
case 0: |
|
clear_nlink(d_inode(dentry)); |
|
break; |
|
case -ENOENT: |
|
nfs_dentry_handle_enoent(dentry); |
|
} |
|
up_write(&NFS_I(d_inode(dentry))->rmdir_sem); |
|
} else |
|
error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name); |
|
trace_nfs_rmdir_exit(dir, dentry, error); |
|
|
|
return error; |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_rmdir); |
|
|
|
/* |
|
* Remove a file after making sure there are no pending writes, |
|
* and after checking that the file has only one user. |
|
* |
|
* We invalidate the attribute cache and free the inode prior to the operation |
|
* to avoid possible races if the server reuses the inode. |
|
*/ |
|
static int nfs_safe_remove(struct dentry *dentry) |
|
{ |
|
struct inode *dir = d_inode(dentry->d_parent); |
|
struct inode *inode = d_inode(dentry); |
|
int error = -EBUSY; |
|
|
|
dfprintk(VFS, "NFS: safe_remove(%pd2)\n", dentry); |
|
|
|
/* If the dentry was sillyrenamed, we simply call d_delete() */ |
|
if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { |
|
error = 0; |
|
goto out; |
|
} |
|
|
|
trace_nfs_remove_enter(dir, dentry); |
|
if (inode != NULL) { |
|
error = NFS_PROTO(dir)->remove(dir, dentry); |
|
if (error == 0) |
|
nfs_drop_nlink(inode); |
|
} else |
|
error = NFS_PROTO(dir)->remove(dir, dentry); |
|
if (error == -ENOENT) |
|
nfs_dentry_handle_enoent(dentry); |
|
trace_nfs_remove_exit(dir, dentry, error); |
|
out: |
|
return error; |
|
} |
|
|
|
/* We do silly rename. In case sillyrename() returns -EBUSY, the inode |
|
* belongs to an active ".nfs..." file and we return -EBUSY. |
|
* |
|
* If sillyrename() returns 0, we do nothing, otherwise we unlink. |
|
*/ |
|
int nfs_unlink(struct inode *dir, struct dentry *dentry) |
|
{ |
|
int error; |
|
int need_rehash = 0; |
|
|
|
dfprintk(VFS, "NFS: unlink(%s/%lu, %pd)\n", dir->i_sb->s_id, |
|
dir->i_ino, dentry); |
|
|
|
trace_nfs_unlink_enter(dir, dentry); |
|
spin_lock(&dentry->d_lock); |
|
if (d_count(dentry) > 1) { |
|
spin_unlock(&dentry->d_lock); |
|
/* Start asynchronous writeout of the inode */ |
|
write_inode_now(d_inode(dentry), 0); |
|
error = nfs_sillyrename(dir, dentry); |
|
goto out; |
|
} |
|
if (!d_unhashed(dentry)) { |
|
__d_drop(dentry); |
|
need_rehash = 1; |
|
} |
|
spin_unlock(&dentry->d_lock); |
|
error = nfs_safe_remove(dentry); |
|
if (!error || error == -ENOENT) { |
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
|
} else if (need_rehash) |
|
d_rehash(dentry); |
|
out: |
|
trace_nfs_unlink_exit(dir, dentry, error); |
|
return error; |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_unlink); |
|
|
|
/* |
|
* To create a symbolic link, most file systems instantiate a new inode, |
|
* add a page to it containing the path, then write it out to the disk |
|
* using prepare_write/commit_write. |
|
* |
|
* Unfortunately the NFS client can't create the in-core inode first |
|
* because it needs a file handle to create an in-core inode (see |
|
* fs/nfs/inode.c:nfs_fhget). We only have a file handle *after* the |
|
* symlink request has completed on the server. |
|
* |
|
* So instead we allocate a raw page, copy the symname into it, then do |
|
* the SYMLINK request with the page as the buffer. If it succeeds, we |
|
* now have a new file handle and can instantiate an in-core NFS inode |
|
* and move the raw page into its mapping. |
|
*/ |
|
int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) |
|
{ |
|
struct page *page; |
|
char *kaddr; |
|
struct iattr attr; |
|
unsigned int pathlen = strlen(symname); |
|
int error; |
|
|
|
dfprintk(VFS, "NFS: symlink(%s/%lu, %pd, %s)\n", dir->i_sb->s_id, |
|
dir->i_ino, dentry, symname); |
|
|
|
if (pathlen > PAGE_SIZE) |
|
return -ENAMETOOLONG; |
|
|
|
attr.ia_mode = S_IFLNK | S_IRWXUGO; |
|
attr.ia_valid = ATTR_MODE; |
|
|
|
page = alloc_page(GFP_USER); |
|
if (!page) |
|
return -ENOMEM; |
|
|
|
kaddr = page_address(page); |
|
memcpy(kaddr, symname, pathlen); |
|
if (pathlen < PAGE_SIZE) |
|
memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen); |
|
|
|
trace_nfs_symlink_enter(dir, dentry); |
|
error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr); |
|
trace_nfs_symlink_exit(dir, dentry, error); |
|
if (error != 0) { |
|
dfprintk(VFS, "NFS: symlink(%s/%lu, %pd, %s) error %d\n", |
|
dir->i_sb->s_id, dir->i_ino, |
|
dentry, symname, error); |
|
d_drop(dentry); |
|
__free_page(page); |
|
return error; |
|
} |
|
|
|
/* |
|
* No big deal if we can't add this page to the page cache here. |
|
* READLINK will get the missing page from the server if needed. |
|
*/ |
|
if (!add_to_page_cache_lru(page, d_inode(dentry)->i_mapping, 0, |
|
GFP_KERNEL)) { |
|
SetPageUptodate(page); |
|
unlock_page(page); |
|
/* |
|
* add_to_page_cache_lru() grabs an extra page refcount. |
|
* Drop it here to avoid leaking this page later. |
|
*/ |
|
put_page(page); |
|
} else |
|
__free_page(page); |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_symlink); |
|
|
|
int |
|
nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) |
|
{ |
|
struct inode *inode = d_inode(old_dentry); |
|
int error; |
|
|
|
dfprintk(VFS, "NFS: link(%pd2 -> %pd2)\n", |
|
old_dentry, dentry); |
|
|
|
trace_nfs_link_enter(inode, dir, dentry); |
|
d_drop(dentry); |
|
error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name); |
|
if (error == 0) { |
|
ihold(inode); |
|
d_add(dentry, inode); |
|
} |
|
trace_nfs_link_exit(inode, dir, dentry, error); |
|
return error; |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_link); |
|
|
|
/* |
|
* RENAME |
|
* FIXME: Some nfsds, like the Linux user space nfsd, may generate a |
|
* different file handle for the same inode after a rename (e.g. when |
|
* moving to a different directory). A fail-safe method to do so would |
|
* be to look up old_dir/old_name, create a link to new_dir/new_name and |
|
* rename the old file using the sillyrename stuff. This way, the original |
|
* file in old_dir will go away when the last process iput()s the inode. |
|
* |
|
* FIXED. |
|
* |
|
* It actually works quite well. One needs to have the possibility for |
|
* at least one ".nfs..." file in each directory the file ever gets |
|
* moved or linked to which happens automagically with the new |
|
* implementation that only depends on the dcache stuff instead of |
|
* using the inode layer |
|
* |
|
* Unfortunately, things are a little more complicated than indicated |
|
* above. For a cross-directory move, we want to make sure we can get |
|
* rid of the old inode after the operation. This means there must be |
|
* no pending writes (if it's a file), and the use count must be 1. |
|
* If these conditions are met, we can drop the dentries before doing |
|
* the rename. |
|
*/ |
|
int nfs_rename(struct inode *old_dir, struct dentry *old_dentry, |
|
struct inode *new_dir, struct dentry *new_dentry, |
|
unsigned int flags) |
|
{ |
|
struct inode *old_inode = d_inode(old_dentry); |
|
struct inode *new_inode = d_inode(new_dentry); |
|
struct dentry *dentry = NULL, *rehash = NULL; |
|
struct rpc_task *task; |
|
int error = -EBUSY; |
|
|
|
if (flags) |
|
return -EINVAL; |
|
|
|
dfprintk(VFS, "NFS: rename(%pd2 -> %pd2, ct=%d)\n", |
|
old_dentry, new_dentry, |
|
d_count(new_dentry)); |
|
|
|
trace_nfs_rename_enter(old_dir, old_dentry, new_dir, new_dentry); |
|
/* |
|
* For non-directories, check whether the target is busy and if so, |
|
* make a copy of the dentry and then do a silly-rename. If the |
|
* silly-rename succeeds, the copied dentry is hashed and becomes |
|
* the new target. |
|
*/ |
|
if (new_inode && !S_ISDIR(new_inode->i_mode)) { |
|
/* |
|
* To prevent any new references to the target during the |
|
* rename, we unhash the dentry in advance. |
|
*/ |
|
if (!d_unhashed(new_dentry)) { |
|
d_drop(new_dentry); |
|
rehash = new_dentry; |
|
} |
|
|
|
if (d_count(new_dentry) > 2) { |
|
int err; |
|
|
|
/* copy the target dentry's name */ |
|
dentry = d_alloc(new_dentry->d_parent, |
|
&new_dentry->d_name); |
|
if (!dentry) |
|
goto out; |
|
|
|
/* silly-rename the existing target ... */ |
|
err = nfs_sillyrename(new_dir, new_dentry); |
|
if (err) |
|
goto out; |
|
|
|
new_dentry = dentry; |
|
rehash = NULL; |
|
new_inode = NULL; |
|
} |
|
} |
|
|
|
task = nfs_async_rename(old_dir, new_dir, old_dentry, new_dentry, NULL); |
|
if (IS_ERR(task)) { |
|
error = PTR_ERR(task); |
|
goto out; |
|
} |
|
|
|
error = rpc_wait_for_completion_task(task); |
|
if (error != 0) { |
|
((struct nfs_renamedata *)task->tk_calldata)->cancelled = 1; |
|
/* Paired with the atomic_dec_and_test() barrier in rpc_do_put_task() */ |
|
smp_wmb(); |
|
} else |
|
error = task->tk_status; |
|
rpc_put_task(task); |
|
/* Ensure the inode attributes are revalidated */ |
|
if (error == 0) { |
|
spin_lock(&old_inode->i_lock); |
|
NFS_I(old_inode)->attr_gencount = nfs_inc_attr_generation_counter(); |
|
NFS_I(old_inode)->cache_validity |= NFS_INO_INVALID_CHANGE |
|
| NFS_INO_INVALID_CTIME |
|
| NFS_INO_REVAL_FORCED; |
|
spin_unlock(&old_inode->i_lock); |
|
} |
|
out: |
|
if (rehash) |
|
d_rehash(rehash); |
|
trace_nfs_rename_exit(old_dir, old_dentry, |
|
new_dir, new_dentry, error); |
|
if (!error) { |
|
if (new_inode != NULL) |
|
nfs_drop_nlink(new_inode); |
|
/* |
|
* The d_move() should be here instead of in an async RPC completion |
|
* handler because we need the proper locks to move the dentry. If |
|
* we're interrupted by a signal, the async RPC completion handler |
|
* should mark the directories for revalidation. |
|
*/ |
|
d_move(old_dentry, new_dentry); |
|
nfs_set_verifier(old_dentry, |
|
nfs_save_change_attribute(new_dir)); |
|
} else if (error == -ENOENT) |
|
nfs_dentry_handle_enoent(old_dentry); |
|
|
|
/* new dentry created? */ |
|
if (dentry) |
|
dput(dentry); |
|
return error; |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_rename); |
|
|
|
static DEFINE_SPINLOCK(nfs_access_lru_lock); |
|
static LIST_HEAD(nfs_access_lru_list); |
|
static atomic_long_t nfs_access_nr_entries; |
|
|
|
static unsigned long nfs_access_max_cachesize = 4*1024*1024; |
|
module_param(nfs_access_max_cachesize, ulong, 0644); |
|
MODULE_PARM_DESC(nfs_access_max_cachesize, "NFS access maximum total cache length"); |
|
|
|
static void nfs_access_free_entry(struct nfs_access_entry *entry) |
|
{ |
|
put_cred(entry->cred); |
|
kfree_rcu(entry, rcu_head); |
|
smp_mb__before_atomic(); |
|
atomic_long_dec(&nfs_access_nr_entries); |
|
smp_mb__after_atomic(); |
|
} |
|
|
|
static void nfs_access_free_list(struct list_head *head) |
|
{ |
|
struct nfs_access_entry *cache; |
|
|
|
while (!list_empty(head)) { |
|
cache = list_entry(head->next, struct nfs_access_entry, lru); |
|
list_del(&cache->lru); |
|
nfs_access_free_entry(cache); |
|
} |
|
} |
|
|
|
static unsigned long |
|
nfs_do_access_cache_scan(unsigned int nr_to_scan) |
|
{ |
|
LIST_HEAD(head); |
|
struct nfs_inode *nfsi, *next; |
|
struct nfs_access_entry *cache; |
|
long freed = 0; |
|
|
|
spin_lock(&nfs_access_lru_lock); |
|
list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) { |
|
struct inode *inode; |
|
|
|
if (nr_to_scan-- == 0) |
|
break; |
|
inode = &nfsi->vfs_inode; |
|
spin_lock(&inode->i_lock); |
|
if (list_empty(&nfsi->access_cache_entry_lru)) |
|
goto remove_lru_entry; |
|
cache = list_entry(nfsi->access_cache_entry_lru.next, |
|
struct nfs_access_entry, lru); |
|
list_move(&cache->lru, &head); |
|
rb_erase(&cache->rb_node, &nfsi->access_cache); |
|
freed++; |
|
if (!list_empty(&nfsi->access_cache_entry_lru)) |
|
list_move_tail(&nfsi->access_cache_inode_lru, |
|
&nfs_access_lru_list); |
|
else { |
|
remove_lru_entry: |
|
list_del_init(&nfsi->access_cache_inode_lru); |
|
smp_mb__before_atomic(); |
|
clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags); |
|
smp_mb__after_atomic(); |
|
} |
|
spin_unlock(&inode->i_lock); |
|
} |
|
spin_unlock(&nfs_access_lru_lock); |
|
nfs_access_free_list(&head); |
|
return freed; |
|
} |
|
|
|
unsigned long |
|
nfs_access_cache_scan(struct shrinker *shrink, struct shrink_control *sc) |
|
{ |
|
int nr_to_scan = sc->nr_to_scan; |
|
gfp_t gfp_mask = sc->gfp_mask; |
|
|
|
if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL) |
|
return SHRINK_STOP; |
|
return nfs_do_access_cache_scan(nr_to_scan); |
|
} |
|
|
|
|
|
unsigned long |
|
nfs_access_cache_count(struct shrinker *shrink, struct shrink_control *sc) |
|
{ |
|
return vfs_pressure_ratio(atomic_long_read(&nfs_access_nr_entries)); |
|
} |
|
|
|
static void |
|
nfs_access_cache_enforce_limit(void) |
|
{ |
|
long nr_entries = atomic_long_read(&nfs_access_nr_entries); |
|
unsigned long diff; |
|
unsigned int nr_to_scan; |
|
|
|
if (nr_entries < 0 || nr_entries <= nfs_access_max_cachesize) |
|
return; |
|
nr_to_scan = 100; |
|
diff = nr_entries - nfs_access_max_cachesize; |
|
if (diff < nr_to_scan) |
|
nr_to_scan = diff; |
|
nfs_do_access_cache_scan(nr_to_scan); |
|
} |
|
|
|
static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head) |
|
{ |
|
struct rb_root *root_node = &nfsi->access_cache; |
|
struct rb_node *n; |
|
struct nfs_access_entry *entry; |
|
|
|
/* Unhook entries from the cache */ |
|
while ((n = rb_first(root_node)) != NULL) { |
|
entry = rb_entry(n, struct nfs_access_entry, rb_node); |
|
rb_erase(n, root_node); |
|
list_move(&entry->lru, head); |
|
} |
|
nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS; |
|
} |
|
|
|
void nfs_access_zap_cache(struct inode *inode) |
|
{ |
|
LIST_HEAD(head); |
|
|
|
if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0) |
|
return; |
|
/* Remove from global LRU init */ |
|
spin_lock(&nfs_access_lru_lock); |
|
if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) |
|
list_del_init(&NFS_I(inode)->access_cache_inode_lru); |
|
|
|
spin_lock(&inode->i_lock); |
|
__nfs_access_zap_cache(NFS_I(inode), &head); |
|
spin_unlock(&inode->i_lock); |
|
spin_unlock(&nfs_access_lru_lock); |
|
nfs_access_free_list(&head); |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_access_zap_cache); |
|
|
|
static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, const struct cred *cred) |
|
{ |
|
struct rb_node *n = NFS_I(inode)->access_cache.rb_node; |
|
|
|
while (n != NULL) { |
|
struct nfs_access_entry *entry = |
|
rb_entry(n, struct nfs_access_entry, rb_node); |
|
int cmp = cred_fscmp(cred, entry->cred); |
|
|
|
if (cmp < 0) |
|
n = n->rb_left; |
|
else if (cmp > 0) |
|
n = n->rb_right; |
|
else |
|
return entry; |
|
} |
|
return NULL; |
|
} |
|
|
|
static int nfs_access_get_cached_locked(struct inode *inode, const struct cred *cred, struct nfs_access_entry *res, bool may_block) |
|
{ |
|
struct nfs_inode *nfsi = NFS_I(inode); |
|
struct nfs_access_entry *cache; |
|
bool retry = true; |
|
int err; |
|
|
|
spin_lock(&inode->i_lock); |
|
for(;;) { |
|
if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS) |
|
goto out_zap; |
|
cache = nfs_access_search_rbtree(inode, cred); |
|
err = -ENOENT; |
|
if (cache == NULL) |
|
goto out; |
|
/* Found an entry, is our attribute cache valid? */ |
|
if (!nfs_check_cache_invalid(inode, NFS_INO_INVALID_ACCESS)) |
|
break; |
|
if (!retry) |
|
break; |
|
err = -ECHILD; |
|
if (!may_block) |
|
goto out; |
|
spin_unlock(&inode->i_lock); |
|
err = __nfs_revalidate_inode(NFS_SERVER(inode), inode); |
|
if (err) |
|
return err; |
|
spin_lock(&inode->i_lock); |
|
retry = false; |
|
} |
|
res->cred = cache->cred; |
|
res->mask = cache->mask; |
|
list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru); |
|
err = 0; |
|
out: |
|
spin_unlock(&inode->i_lock); |
|
return err; |
|
out_zap: |
|
spin_unlock(&inode->i_lock); |
|
nfs_access_zap_cache(inode); |
|
return -ENOENT; |
|
} |
|
|
|
static int nfs_access_get_cached_rcu(struct inode *inode, const struct cred *cred, struct nfs_access_entry *res) |
|
{ |
|
/* Only check the most recently returned cache entry, |
|
* but do it without locking. |
|
*/ |
|
struct nfs_inode *nfsi = NFS_I(inode); |
|
struct nfs_access_entry *cache; |
|
int err = -ECHILD; |
|
struct list_head *lh; |
|
|
|
rcu_read_lock(); |
|
if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS) |
|
goto out; |
|
lh = rcu_dereference(list_tail_rcu(&nfsi->access_cache_entry_lru)); |
|
cache = list_entry(lh, struct nfs_access_entry, lru); |
|
if (lh == &nfsi->access_cache_entry_lru || |
|
cred_fscmp(cred, cache->cred) != 0) |
|
cache = NULL; |
|
if (cache == NULL) |
|
goto out; |
|
if (nfs_check_cache_invalid(inode, NFS_INO_INVALID_ACCESS)) |
|
goto out; |
|
res->cred = cache->cred; |
|
res->mask = cache->mask; |
|
err = 0; |
|
out: |
|
rcu_read_unlock(); |
|
return err; |
|
} |
|
|
|
int nfs_access_get_cached(struct inode *inode, const struct cred *cred, struct |
|
nfs_access_entry *res, bool may_block) |
|
{ |
|
int status; |
|
|
|
status = nfs_access_get_cached_rcu(inode, cred, res); |
|
if (status != 0) |
|
status = nfs_access_get_cached_locked(inode, cred, res, |
|
may_block); |
|
|
|
return status; |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_access_get_cached); |
|
|
|
static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set) |
|
{ |
|
struct nfs_inode *nfsi = NFS_I(inode); |
|
struct rb_root *root_node = &nfsi->access_cache; |
|
struct rb_node **p = &root_node->rb_node; |
|
struct rb_node *parent = NULL; |
|
struct nfs_access_entry *entry; |
|
int cmp; |
|
|
|
spin_lock(&inode->i_lock); |
|
while (*p != NULL) { |
|
parent = *p; |
|
entry = rb_entry(parent, struct nfs_access_entry, rb_node); |
|
cmp = cred_fscmp(set->cred, entry->cred); |
|
|
|
if (cmp < 0) |
|
p = &parent->rb_left; |
|
else if (cmp > 0) |
|
p = &parent->rb_right; |
|
else |
|
goto found; |
|
} |
|
rb_link_node(&set->rb_node, parent, p); |
|
rb_insert_color(&set->rb_node, root_node); |
|
list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); |
|
spin_unlock(&inode->i_lock); |
|
return; |
|
found: |
|
rb_replace_node(parent, &set->rb_node, root_node); |
|
list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); |
|
list_del(&entry->lru); |
|
spin_unlock(&inode->i_lock); |
|
nfs_access_free_entry(entry); |
|
} |
|
|
|
void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set) |
|
{ |
|
struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL); |
|
if (cache == NULL) |
|
return; |
|
RB_CLEAR_NODE(&cache->rb_node); |
|
cache->cred = get_cred(set->cred); |
|
cache->mask = set->mask; |
|
|
|
/* The above field assignments must be visible |
|
* before this item appears on the lru. We cannot easily |
|
* use rcu_assign_pointer, so just force the memory barrier. |
|
*/ |
|
smp_wmb(); |
|
nfs_access_add_rbtree(inode, cache); |
|
|
|
/* Update accounting */ |
|
smp_mb__before_atomic(); |
|
atomic_long_inc(&nfs_access_nr_entries); |
|
smp_mb__after_atomic(); |
|
|
|
/* Add inode to global LRU list */ |
|
if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) { |
|
spin_lock(&nfs_access_lru_lock); |
|
if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) |
|
list_add_tail(&NFS_I(inode)->access_cache_inode_lru, |
|
&nfs_access_lru_list); |
|
spin_unlock(&nfs_access_lru_lock); |
|
} |
|
nfs_access_cache_enforce_limit(); |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_access_add_cache); |
|
|
|
#define NFS_MAY_READ (NFS_ACCESS_READ) |
|
#define NFS_MAY_WRITE (NFS_ACCESS_MODIFY | \ |
|
NFS_ACCESS_EXTEND | \ |
|
NFS_ACCESS_DELETE) |
|
#define NFS_FILE_MAY_WRITE (NFS_ACCESS_MODIFY | \ |
|
NFS_ACCESS_EXTEND) |
|
#define NFS_DIR_MAY_WRITE NFS_MAY_WRITE |
|
#define NFS_MAY_LOOKUP (NFS_ACCESS_LOOKUP) |
|
#define NFS_MAY_EXECUTE (NFS_ACCESS_EXECUTE) |
|
static int |
|
nfs_access_calc_mask(u32 access_result, umode_t umode) |
|
{ |
|
int mask = 0; |
|
|
|
if (access_result & NFS_MAY_READ) |
|
mask |= MAY_READ; |
|
if (S_ISDIR(umode)) { |
|
if ((access_result & NFS_DIR_MAY_WRITE) == NFS_DIR_MAY_WRITE) |
|
mask |= MAY_WRITE; |
|
if ((access_result & NFS_MAY_LOOKUP) == NFS_MAY_LOOKUP) |
|
mask |= MAY_EXEC; |
|
} else if (S_ISREG(umode)) { |
|
if ((access_result & NFS_FILE_MAY_WRITE) == NFS_FILE_MAY_WRITE) |
|
mask |= MAY_WRITE; |
|
if ((access_result & NFS_MAY_EXECUTE) == NFS_MAY_EXECUTE) |
|
mask |= MAY_EXEC; |
|
} else if (access_result & NFS_MAY_WRITE) |
|
mask |= MAY_WRITE; |
|
return mask; |
|
} |
|
|
|
void nfs_access_set_mask(struct nfs_access_entry *entry, u32 access_result) |
|
{ |
|
entry->mask = access_result; |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_access_set_mask); |
|
|
|
static int nfs_do_access(struct inode *inode, const struct cred *cred, int mask) |
|
{ |
|
struct nfs_access_entry cache; |
|
bool may_block = (mask & MAY_NOT_BLOCK) == 0; |
|
int cache_mask = -1; |
|
int status; |
|
|
|
trace_nfs_access_enter(inode); |
|
|
|
status = nfs_access_get_cached(inode, cred, &cache, may_block); |
|
if (status == 0) |
|
goto out_cached; |
|
|
|
status = -ECHILD; |
|
if (!may_block) |
|
goto out; |
|
|
|
/* |
|
* Determine which access bits we want to ask for... |
|
*/ |
|
cache.mask = NFS_ACCESS_READ | NFS_ACCESS_MODIFY | NFS_ACCESS_EXTEND; |
|
if (nfs_server_capable(inode, NFS_CAP_XATTR)) { |
|
cache.mask |= NFS_ACCESS_XAREAD | NFS_ACCESS_XAWRITE | |
|
NFS_ACCESS_XALIST; |
|
} |
|
if (S_ISDIR(inode->i_mode)) |
|
cache.mask |= NFS_ACCESS_DELETE | NFS_ACCESS_LOOKUP; |
|
else |
|
cache.mask |= NFS_ACCESS_EXECUTE; |
|
cache.cred = cred; |
|
status = NFS_PROTO(inode)->access(inode, &cache); |
|
if (status != 0) { |
|
if (status == -ESTALE) { |
|
if (!S_ISDIR(inode->i_mode)) |
|
nfs_set_inode_stale(inode); |
|
else |
|
nfs_zap_caches(inode); |
|
} |
|
goto out; |
|
} |
|
nfs_access_add_cache(inode, &cache); |
|
out_cached: |
|
cache_mask = nfs_access_calc_mask(cache.mask, inode->i_mode); |
|
if ((mask & ~cache_mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) != 0) |
|
status = -EACCES; |
|
out: |
|
trace_nfs_access_exit(inode, mask, cache_mask, status); |
|
return status; |
|
} |
|
|
|
static int nfs_open_permission_mask(int openflags) |
|
{ |
|
int mask = 0; |
|
|
|
if (openflags & __FMODE_EXEC) { |
|
/* ONLY check exec rights */ |
|
mask = MAY_EXEC; |
|
} else { |
|
if ((openflags & O_ACCMODE) != O_WRONLY) |
|
mask |= MAY_READ; |
|
if ((openflags & O_ACCMODE) != O_RDONLY) |
|
mask |= MAY_WRITE; |
|
} |
|
|
|
return mask; |
|
} |
|
|
|
int nfs_may_open(struct inode *inode, const struct cred *cred, int openflags) |
|
{ |
|
return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags)); |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_may_open); |
|
|
|
static int nfs_execute_ok(struct inode *inode, int mask) |
|
{ |
|
struct nfs_server *server = NFS_SERVER(inode); |
|
int ret = 0; |
|
|
|
if (S_ISDIR(inode->i_mode)) |
|
return 0; |
|
if (nfs_check_cache_invalid(inode, NFS_INO_INVALID_OTHER)) { |
|
if (mask & MAY_NOT_BLOCK) |
|
return -ECHILD; |
|
ret = __nfs_revalidate_inode(server, inode); |
|
} |
|
if (ret == 0 && !execute_ok(inode)) |
|
ret = -EACCES; |
|
return ret; |
|
} |
|
|
|
int nfs_permission(struct inode *inode, int mask) |
|
{ |
|
const struct cred *cred = current_cred(); |
|
int res = 0; |
|
|
|
nfs_inc_stats(inode, NFSIOS_VFSACCESS); |
|
|
|
if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) |
|
goto out; |
|
/* Is this sys_access() ? */ |
|
if (mask & (MAY_ACCESS | MAY_CHDIR)) |
|
goto force_lookup; |
|
|
|
switch (inode->i_mode & S_IFMT) { |
|
case S_IFLNK: |
|
goto out; |
|
case S_IFREG: |
|
if ((mask & MAY_OPEN) && |
|
nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN)) |
|
return 0; |
|
break; |
|
case S_IFDIR: |
|
/* |
|
* Optimize away all write operations, since the server |
|
* will check permissions when we perform the op. |
|
*/ |
|
if ((mask & MAY_WRITE) && !(mask & MAY_READ)) |
|
goto out; |
|
} |
|
|
|
force_lookup: |
|
if (!NFS_PROTO(inode)->access) |
|
goto out_notsup; |
|
|
|
res = nfs_do_access(inode, cred, mask); |
|
out: |
|
if (!res && (mask & MAY_EXEC)) |
|
res = nfs_execute_ok(inode, mask); |
|
|
|
dfprintk(VFS, "NFS: permission(%s/%lu), mask=0x%x, res=%d\n", |
|
inode->i_sb->s_id, inode->i_ino, mask, res); |
|
return res; |
|
out_notsup: |
|
if (mask & MAY_NOT_BLOCK) |
|
return -ECHILD; |
|
|
|
res = nfs_revalidate_inode(NFS_SERVER(inode), inode); |
|
if (res == 0) |
|
res = generic_permission(inode, mask); |
|
goto out; |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_permission); |
|
|
|
/* |
|
* Local variables: |
|
* version-control: t |
|
* kept-new-versions: 5 |
|
* End: |
|
*/
|
|
|