![Miklos Szeredi](/assets/img/avatar_default.png)
The d_instantiate(new_dentry, NULL) is superfluous, the dentry is already negative. Rehashing this dummy dentry isn't needed either, d_move() works fine on an unhashed target. The re-checking for busy after a failed nfs_sillyrename() is bogus too: new_dentry->d_count < 2 would be a bug here. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
1981 lines
52 KiB
C
1981 lines
52 KiB
C
/*
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* linux/fs/nfs/dir.c
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*
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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 claus@momo.math.rwth-aachen.de
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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/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>
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#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/sched.h>
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#include "nfs4_fs.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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/* #define NFS_DEBUG_VERBOSE 1 */
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static int nfs_opendir(struct inode *, struct file *);
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static int nfs_readdir(struct file *, void *, filldir_t);
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static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *);
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static int nfs_create(struct inode *, struct dentry *, int, struct nameidata *);
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static int nfs_mkdir(struct inode *, struct dentry *, int);
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static int nfs_rmdir(struct inode *, struct dentry *);
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static int nfs_unlink(struct inode *, struct dentry *);
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static int nfs_symlink(struct inode *, struct dentry *, const char *);
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static int nfs_link(struct dentry *, struct inode *, struct dentry *);
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static int nfs_mknod(struct inode *, struct dentry *, int, dev_t);
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static int nfs_rename(struct inode *, struct dentry *,
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struct inode *, struct dentry *);
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static int nfs_fsync_dir(struct file *, struct dentry *, int);
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static loff_t nfs_llseek_dir(struct file *, loff_t, int);
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const struct file_operations nfs_dir_operations = {
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.llseek = nfs_llseek_dir,
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.read = generic_read_dir,
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.readdir = nfs_readdir,
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.open = nfs_opendir,
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.release = nfs_release,
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.fsync = nfs_fsync_dir,
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};
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const struct inode_operations nfs_dir_inode_operations = {
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.create = nfs_create,
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.lookup = nfs_lookup,
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.link = nfs_link,
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.unlink = nfs_unlink,
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.symlink = nfs_symlink,
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.mkdir = nfs_mkdir,
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.rmdir = nfs_rmdir,
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.mknod = nfs_mknod,
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.rename = nfs_rename,
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.permission = nfs_permission,
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.getattr = nfs_getattr,
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.setattr = nfs_setattr,
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};
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#ifdef CONFIG_NFS_V3
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const struct inode_operations nfs3_dir_inode_operations = {
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.create = nfs_create,
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.lookup = nfs_lookup,
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.link = nfs_link,
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.unlink = nfs_unlink,
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.symlink = nfs_symlink,
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.mkdir = nfs_mkdir,
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.rmdir = nfs_rmdir,
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.mknod = nfs_mknod,
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.rename = nfs_rename,
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.permission = nfs_permission,
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.getattr = nfs_getattr,
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.setattr = nfs_setattr,
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.listxattr = nfs3_listxattr,
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.getxattr = nfs3_getxattr,
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.setxattr = nfs3_setxattr,
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.removexattr = nfs3_removexattr,
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};
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#endif /* CONFIG_NFS_V3 */
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#ifdef CONFIG_NFS_V4
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static struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *);
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const struct inode_operations nfs4_dir_inode_operations = {
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.create = nfs_create,
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.lookup = nfs_atomic_lookup,
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.link = nfs_link,
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.unlink = nfs_unlink,
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.symlink = nfs_symlink,
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.mkdir = nfs_mkdir,
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.rmdir = nfs_rmdir,
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.mknod = nfs_mknod,
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.rename = nfs_rename,
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.permission = nfs_permission,
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.getattr = nfs_getattr,
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.setattr = nfs_setattr,
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.getxattr = nfs4_getxattr,
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.setxattr = nfs4_setxattr,
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.listxattr = nfs4_listxattr,
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};
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#endif /* CONFIG_NFS_V4 */
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/*
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* Open file
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*/
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static int
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nfs_opendir(struct inode *inode, struct file *filp)
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{
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int res;
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dfprintk(FILE, "NFS: open dir(%s/%s)\n",
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filp->f_path.dentry->d_parent->d_name.name,
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filp->f_path.dentry->d_name.name);
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nfs_inc_stats(inode, NFSIOS_VFSOPEN);
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/* Call generic open code in order to cache credentials */
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res = nfs_open(inode, filp);
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return res;
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}
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typedef __be32 * (*decode_dirent_t)(__be32 *, struct nfs_entry *, int);
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typedef struct {
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struct file *file;
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struct page *page;
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unsigned long page_index;
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__be32 *ptr;
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u64 *dir_cookie;
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loff_t current_index;
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struct nfs_entry *entry;
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decode_dirent_t decode;
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int plus;
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unsigned long timestamp;
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unsigned long gencount;
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int timestamp_valid;
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} nfs_readdir_descriptor_t;
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/* Now we cache directories properly, by stuffing the dirent
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* data directly in the page cache.
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*
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* Inode invalidation due to refresh etc. takes care of
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* _everything_, no sloppy entry flushing logic, no extraneous
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* copying, network direct to page cache, the way it was meant
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* to be.
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*
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* NOTE: Dirent information verification is done always by the
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* page-in of the RPC reply, nowhere else, this simplies
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* things substantially.
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*/
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static
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int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page *page)
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{
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struct file *file = desc->file;
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struct inode *inode = file->f_path.dentry->d_inode;
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struct rpc_cred *cred = nfs_file_cred(file);
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unsigned long timestamp, gencount;
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int error;
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dfprintk(DIRCACHE, "NFS: %s: reading cookie %Lu into page %lu\n",
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__func__, (long long)desc->entry->cookie,
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page->index);
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again:
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timestamp = jiffies;
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gencount = nfs_inc_attr_generation_counter();
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error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, desc->entry->cookie, page,
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NFS_SERVER(inode)->dtsize, desc->plus);
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if (error < 0) {
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/* We requested READDIRPLUS, but the server doesn't grok it */
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if (error == -ENOTSUPP && desc->plus) {
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NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS;
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clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
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desc->plus = 0;
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goto again;
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}
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goto error;
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}
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desc->timestamp = timestamp;
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desc->gencount = gencount;
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desc->timestamp_valid = 1;
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SetPageUptodate(page);
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/* Ensure consistent page alignment of the data.
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* Note: assumes we have exclusive access to this mapping either
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* through inode->i_mutex or some other mechanism.
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*/
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if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) {
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/* Should never happen */
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nfs_zap_mapping(inode, inode->i_mapping);
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}
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unlock_page(page);
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return 0;
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error:
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unlock_page(page);
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return -EIO;
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}
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static inline
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int dir_decode(nfs_readdir_descriptor_t *desc)
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{
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__be32 *p = desc->ptr;
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p = desc->decode(p, desc->entry, desc->plus);
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if (IS_ERR(p))
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return PTR_ERR(p);
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desc->ptr = p;
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if (desc->timestamp_valid) {
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desc->entry->fattr->time_start = desc->timestamp;
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desc->entry->fattr->gencount = desc->gencount;
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} else
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desc->entry->fattr->valid &= ~NFS_ATTR_FATTR;
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return 0;
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}
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static inline
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void dir_page_release(nfs_readdir_descriptor_t *desc)
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{
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kunmap(desc->page);
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page_cache_release(desc->page);
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desc->page = NULL;
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desc->ptr = NULL;
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}
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/*
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* Given a pointer to a buffer that has already been filled by a call
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* to readdir, find the next entry with cookie '*desc->dir_cookie'.
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*
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* If the end of the buffer has been reached, return -EAGAIN, if not,
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* return the offset within the buffer of the next entry to be
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* read.
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*/
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static inline
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int find_dirent(nfs_readdir_descriptor_t *desc)
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{
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struct nfs_entry *entry = desc->entry;
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int loop_count = 0,
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status;
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while((status = dir_decode(desc)) == 0) {
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dfprintk(DIRCACHE, "NFS: %s: examining cookie %Lu\n",
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__func__, (unsigned long long)entry->cookie);
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if (entry->prev_cookie == *desc->dir_cookie)
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break;
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if (loop_count++ > 200) {
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loop_count = 0;
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schedule();
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}
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}
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return status;
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}
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/*
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* Given a pointer to a buffer that has already been filled by a call
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* to readdir, find the entry at offset 'desc->file->f_pos'.
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*
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* If the end of the buffer has been reached, return -EAGAIN, if not,
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* return the offset within the buffer of the next entry to be
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* read.
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*/
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static inline
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int find_dirent_index(nfs_readdir_descriptor_t *desc)
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{
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struct nfs_entry *entry = desc->entry;
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int loop_count = 0,
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status;
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for(;;) {
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status = dir_decode(desc);
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if (status)
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break;
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dfprintk(DIRCACHE, "NFS: found cookie %Lu at index %Ld\n",
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(unsigned long long)entry->cookie, desc->current_index);
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if (desc->file->f_pos == desc->current_index) {
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*desc->dir_cookie = entry->cookie;
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break;
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}
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desc->current_index++;
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if (loop_count++ > 200) {
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loop_count = 0;
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schedule();
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}
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}
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return status;
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}
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/*
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* Find the given page, and call find_dirent() or find_dirent_index in
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* order to try to return the next entry.
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*/
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static inline
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int find_dirent_page(nfs_readdir_descriptor_t *desc)
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{
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struct inode *inode = desc->file->f_path.dentry->d_inode;
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struct page *page;
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int status;
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dfprintk(DIRCACHE, "NFS: %s: searching page %ld for target %Lu\n",
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__func__, desc->page_index,
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(long long) *desc->dir_cookie);
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/* If we find the page in the page_cache, we cannot be sure
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* how fresh the data is, so we will ignore readdir_plus attributes.
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*/
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desc->timestamp_valid = 0;
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page = read_cache_page(inode->i_mapping, desc->page_index,
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(filler_t *)nfs_readdir_filler, desc);
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if (IS_ERR(page)) {
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status = PTR_ERR(page);
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goto out;
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}
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/* NOTE: Someone else may have changed the READDIRPLUS flag */
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desc->page = page;
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desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */
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if (*desc->dir_cookie != 0)
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status = find_dirent(desc);
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else
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status = find_dirent_index(desc);
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if (status < 0)
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dir_page_release(desc);
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out:
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dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __func__, status);
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return status;
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}
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/*
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* Recurse through the page cache pages, and return a
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* filled nfs_entry structure of the next directory entry if possible.
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*
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* The target for the search is '*desc->dir_cookie' if non-0,
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* 'desc->file->f_pos' otherwise
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*/
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static inline
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int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
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{
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int loop_count = 0;
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int res;
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/* Always search-by-index from the beginning of the cache */
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if (*desc->dir_cookie == 0) {
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dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for offset %Ld\n",
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(long long)desc->file->f_pos);
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desc->page_index = 0;
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desc->entry->cookie = desc->entry->prev_cookie = 0;
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desc->entry->eof = 0;
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desc->current_index = 0;
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} else
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dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for cookie %Lu\n",
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(unsigned long long)*desc->dir_cookie);
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for (;;) {
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res = find_dirent_page(desc);
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if (res != -EAGAIN)
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break;
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/* Align to beginning of next page */
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desc->page_index ++;
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if (loop_count++ > 200) {
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loop_count = 0;
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schedule();
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}
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}
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dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __func__, res);
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return res;
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}
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static inline unsigned int dt_type(struct inode *inode)
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{
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return (inode->i_mode >> 12) & 15;
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}
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static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc);
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/*
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* Once we've found the start of the dirent within a page: fill 'er up...
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*/
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static
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int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent,
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filldir_t filldir)
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{
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struct file *file = desc->file;
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struct nfs_entry *entry = desc->entry;
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struct dentry *dentry = NULL;
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u64 fileid;
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int loop_count = 0,
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res;
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dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling starting @ cookie %Lu\n",
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(unsigned long long)entry->cookie);
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for(;;) {
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unsigned d_type = DT_UNKNOWN;
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/* Note: entry->prev_cookie contains the cookie for
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* retrieving the current dirent on the server */
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fileid = entry->ino;
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/* Get a dentry if we have one */
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if (dentry != NULL)
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dput(dentry);
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dentry = nfs_readdir_lookup(desc);
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/* Use readdirplus info */
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if (dentry != NULL && dentry->d_inode != NULL) {
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d_type = dt_type(dentry->d_inode);
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fileid = NFS_FILEID(dentry->d_inode);
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}
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res = filldir(dirent, entry->name, entry->len,
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file->f_pos, nfs_compat_user_ino64(fileid),
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d_type);
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if (res < 0)
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break;
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file->f_pos++;
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*desc->dir_cookie = entry->cookie;
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if (dir_decode(desc) != 0) {
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desc->page_index ++;
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break;
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}
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if (loop_count++ > 200) {
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loop_count = 0;
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schedule();
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}
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}
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dir_page_release(desc);
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if (dentry != NULL)
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dput(dentry);
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dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
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(unsigned long long)*desc->dir_cookie, res);
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return res;
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}
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/*
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* If we cannot find a cookie in our cache, we suspect that this is
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* because it points to a deleted file, so we ask the server to return
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* whatever it thinks is the next entry. We then feed this to filldir.
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* If all goes well, we should then be able to find our way round the
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* cache on the next call to readdir_search_pagecache();
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*
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* NOTE: we cannot add the anonymous page to the pagecache because
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* the data it contains might not be page aligned. Besides,
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* we should already have a complete representation of the
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* directory in the page cache by the time we get here.
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*/
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static inline
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int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent,
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filldir_t filldir)
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{
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struct file *file = desc->file;
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struct inode *inode = file->f_path.dentry->d_inode;
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struct rpc_cred *cred = nfs_file_cred(file);
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struct page *page = NULL;
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int status;
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unsigned long timestamp, gencount;
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dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
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(unsigned long long)*desc->dir_cookie);
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page = alloc_page(GFP_HIGHUSER);
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if (!page) {
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status = -ENOMEM;
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goto out;
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}
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timestamp = jiffies;
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gencount = nfs_inc_attr_generation_counter();
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status = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred,
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*desc->dir_cookie, page,
|
|
NFS_SERVER(inode)->dtsize,
|
|
desc->plus);
|
|
desc->page = page;
|
|
desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */
|
|
if (status >= 0) {
|
|
desc->timestamp = timestamp;
|
|
desc->gencount = gencount;
|
|
desc->timestamp_valid = 1;
|
|
if ((status = dir_decode(desc)) == 0)
|
|
desc->entry->prev_cookie = *desc->dir_cookie;
|
|
} else
|
|
status = -EIO;
|
|
if (status < 0)
|
|
goto out_release;
|
|
|
|
status = nfs_do_filldir(desc, dirent, filldir);
|
|
|
|
/* Reset read descriptor so it searches the page cache from
|
|
* the start upon the next call to readdir_search_pagecache() */
|
|
desc->page_index = 0;
|
|
desc->entry->cookie = desc->entry->prev_cookie = 0;
|
|
desc->entry->eof = 0;
|
|
out:
|
|
dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
|
|
__func__, status);
|
|
return status;
|
|
out_release:
|
|
dir_page_release(desc);
|
|
goto out;
|
|
}
|
|
|
|
/* 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 *filp, void *dirent, filldir_t filldir)
|
|
{
|
|
struct dentry *dentry = filp->f_path.dentry;
|
|
struct inode *inode = dentry->d_inode;
|
|
nfs_readdir_descriptor_t my_desc,
|
|
*desc = &my_desc;
|
|
struct nfs_entry my_entry;
|
|
struct nfs_fh fh;
|
|
struct nfs_fattr fattr;
|
|
long res;
|
|
|
|
dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n",
|
|
dentry->d_parent->d_name.name, dentry->d_name.name,
|
|
(long long)filp->f_pos);
|
|
nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);
|
|
|
|
/*
|
|
* filp->f_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.
|
|
*/
|
|
memset(desc, 0, sizeof(*desc));
|
|
|
|
desc->file = filp;
|
|
desc->dir_cookie = &nfs_file_open_context(filp)->dir_cookie;
|
|
desc->decode = NFS_PROTO(inode)->decode_dirent;
|
|
desc->plus = NFS_USE_READDIRPLUS(inode);
|
|
|
|
my_entry.cookie = my_entry.prev_cookie = 0;
|
|
my_entry.eof = 0;
|
|
my_entry.fh = &fh;
|
|
my_entry.fattr = &fattr;
|
|
nfs_fattr_init(&fattr);
|
|
desc->entry = &my_entry;
|
|
|
|
nfs_block_sillyrename(dentry);
|
|
res = nfs_revalidate_mapping_nolock(inode, filp->f_mapping);
|
|
if (res < 0)
|
|
goto out;
|
|
|
|
while(!desc->entry->eof) {
|
|
res = readdir_search_pagecache(desc);
|
|
|
|
if (res == -EBADCOOKIE) {
|
|
/* This means either end of directory */
|
|
if (*desc->dir_cookie && desc->entry->cookie != *desc->dir_cookie) {
|
|
/* Or that the server has 'lost' a cookie */
|
|
res = uncached_readdir(desc, dirent, filldir);
|
|
if (res >= 0)
|
|
continue;
|
|
}
|
|
res = 0;
|
|
break;
|
|
}
|
|
if (res == -ETOOSMALL && desc->plus) {
|
|
clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
|
|
nfs_zap_caches(inode);
|
|
desc->plus = 0;
|
|
desc->entry->eof = 0;
|
|
continue;
|
|
}
|
|
if (res < 0)
|
|
break;
|
|
|
|
res = nfs_do_filldir(desc, dirent, filldir);
|
|
if (res < 0) {
|
|
res = 0;
|
|
break;
|
|
}
|
|
}
|
|
out:
|
|
nfs_unblock_sillyrename(dentry);
|
|
if (res > 0)
|
|
res = 0;
|
|
dfprintk(FILE, "NFS: readdir(%s/%s) returns %ld\n",
|
|
dentry->d_parent->d_name.name, dentry->d_name.name,
|
|
res);
|
|
return res;
|
|
}
|
|
|
|
static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin)
|
|
{
|
|
struct dentry *dentry = filp->f_path.dentry;
|
|
struct inode *inode = dentry->d_inode;
|
|
|
|
dfprintk(FILE, "NFS: llseek dir(%s/%s, %lld, %d)\n",
|
|
dentry->d_parent->d_name.name,
|
|
dentry->d_name.name,
|
|
offset, origin);
|
|
|
|
mutex_lock(&inode->i_mutex);
|
|
switch (origin) {
|
|
case 1:
|
|
offset += filp->f_pos;
|
|
case 0:
|
|
if (offset >= 0)
|
|
break;
|
|
default:
|
|
offset = -EINVAL;
|
|
goto out;
|
|
}
|
|
if (offset != filp->f_pos) {
|
|
filp->f_pos = offset;
|
|
nfs_file_open_context(filp)->dir_cookie = 0;
|
|
}
|
|
out:
|
|
mutex_unlock(&inode->i_mutex);
|
|
return offset;
|
|
}
|
|
|
|
/*
|
|
* All directory operations under NFS are synchronous, so fsync()
|
|
* is a dummy operation.
|
|
*/
|
|
static int nfs_fsync_dir(struct file *filp, struct dentry *dentry, int datasync)
|
|
{
|
|
dfprintk(FILE, "NFS: fsync dir(%s/%s) datasync %d\n",
|
|
dentry->d_parent->d_name.name, dentry->d_name.name,
|
|
datasync);
|
|
|
|
nfs_inc_stats(dentry->d_inode, 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.
|
|
*
|
|
* The caller should be holding dir->i_lock
|
|
*/
|
|
void nfs_force_lookup_revalidate(struct inode *dir)
|
|
{
|
|
NFS_I(dir)->cache_change_attribute++;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
static int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
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_revalidate_inode(NFS_SERVER(dir), dir) < 0)
|
|
return 0;
|
|
if (!nfs_verify_change_attribute(dir, dentry->d_time))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Return the intent data that applies to this particular path component
|
|
*
|
|
* Note that the current set of intents only apply to the very last
|
|
* component of the path.
|
|
* We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT.
|
|
*/
|
|
static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, unsigned int mask)
|
|
{
|
|
if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT))
|
|
return 0;
|
|
return nd->flags & mask;
|
|
}
|
|
|
|
/*
|
|
* 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, struct nameidata *nd)
|
|
{
|
|
if (NFS_PROTO(dir)->version == 2)
|
|
return 0;
|
|
return nd && nfs_lookup_check_intent(nd, 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 inline
|
|
int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd)
|
|
{
|
|
struct nfs_server *server = NFS_SERVER(inode);
|
|
|
|
if (test_bit(NFS_INO_MOUNTPOINT, &NFS_I(inode)->flags))
|
|
return 0;
|
|
if (nd != NULL) {
|
|
/* VFS wants an on-the-wire revalidation */
|
|
if (nd->flags & LOOKUP_REVAL)
|
|
goto out_force;
|
|
/* This is an open(2) */
|
|
if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 &&
|
|
!(server->flags & NFS_MOUNT_NOCTO) &&
|
|
(S_ISREG(inode->i_mode) ||
|
|
S_ISDIR(inode->i_mode)))
|
|
goto out_force;
|
|
return 0;
|
|
}
|
|
return nfs_revalidate_inode(server, inode);
|
|
out_force:
|
|
return __nfs_revalidate_inode(server, inode);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
static inline
|
|
int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
|
|
struct nameidata *nd)
|
|
{
|
|
/* Don't revalidate a negative dentry if we're creating a new file */
|
|
if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0)
|
|
return 0;
|
|
if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG)
|
|
return 1;
|
|
return !nfs_check_verifier(dir, dentry);
|
|
}
|
|
|
|
/*
|
|
* 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_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
|
|
{
|
|
struct inode *dir;
|
|
struct inode *inode;
|
|
struct dentry *parent;
|
|
int error;
|
|
struct nfs_fh fhandle;
|
|
struct nfs_fattr fattr;
|
|
|
|
parent = dget_parent(dentry);
|
|
dir = parent->d_inode;
|
|
nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
|
|
inode = dentry->d_inode;
|
|
|
|
if (!inode) {
|
|
if (nfs_neg_need_reval(dir, dentry, nd))
|
|
goto out_bad;
|
|
goto out_valid;
|
|
}
|
|
|
|
if (is_bad_inode(inode)) {
|
|
dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
|
|
__func__, dentry->d_parent->d_name.name,
|
|
dentry->d_name.name);
|
|
goto out_bad;
|
|
}
|
|
|
|
if (nfs_have_delegation(inode, FMODE_READ))
|
|
goto out_set_verifier;
|
|
|
|
/* Force a full look up iff the parent directory has changed */
|
|
if (!nfs_is_exclusive_create(dir, nd) && nfs_check_verifier(dir, dentry)) {
|
|
if (nfs_lookup_verify_inode(inode, nd))
|
|
goto out_zap_parent;
|
|
goto out_valid;
|
|
}
|
|
|
|
if (NFS_STALE(inode))
|
|
goto out_bad;
|
|
|
|
error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
|
|
if (error)
|
|
goto out_bad;
|
|
if (nfs_compare_fh(NFS_FH(inode), &fhandle))
|
|
goto out_bad;
|
|
if ((error = nfs_refresh_inode(inode, &fattr)) != 0)
|
|
goto out_bad;
|
|
|
|
out_set_verifier:
|
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
|
|
out_valid:
|
|
dput(parent);
|
|
dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n",
|
|
__func__, dentry->d_parent->d_name.name,
|
|
dentry->d_name.name);
|
|
return 1;
|
|
out_zap_parent:
|
|
nfs_zap_caches(dir);
|
|
out_bad:
|
|
nfs_mark_for_revalidate(dir);
|
|
if (inode && S_ISDIR(inode->i_mode)) {
|
|
/* Purge readdir caches. */
|
|
nfs_zap_caches(inode);
|
|
/* If we have submounts, don't unhash ! */
|
|
if (have_submounts(dentry))
|
|
goto out_valid;
|
|
shrink_dcache_parent(dentry);
|
|
}
|
|
d_drop(dentry);
|
|
dput(parent);
|
|
dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
|
|
__func__, dentry->d_parent->d_name.name,
|
|
dentry->d_name.name);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* This is called from dput() when d_count is going to 0.
|
|
*/
|
|
static int nfs_dentry_delete(struct dentry *dentry)
|
|
{
|
|
dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n",
|
|
dentry->d_parent->d_name.name, dentry->d_name.name,
|
|
dentry->d_flags);
|
|
|
|
/* Unhash any dentry with a stale inode */
|
|
if (dentry->d_inode != NULL && NFS_STALE(dentry->d_inode))
|
|
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 & MS_ACTIVE)) {
|
|
/* Unhash it, so that ancestors of killed async unlink
|
|
* files will be cleaned up during umount */
|
|
return 1;
|
|
}
|
|
return 0;
|
|
|
|
}
|
|
|
|
static void nfs_drop_nlink(struct inode *inode)
|
|
{
|
|
spin_lock(&inode->i_lock);
|
|
if (inode->i_nlink > 0)
|
|
drop_nlink(inode);
|
|
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) {
|
|
drop_nlink(inode);
|
|
nfs_complete_unlink(dentry, inode);
|
|
}
|
|
iput(inode);
|
|
}
|
|
|
|
const struct dentry_operations nfs_dentry_operations = {
|
|
.d_revalidate = nfs_lookup_revalidate,
|
|
.d_delete = nfs_dentry_delete,
|
|
.d_iput = nfs_dentry_iput,
|
|
};
|
|
|
|
static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
|
|
{
|
|
struct dentry *res;
|
|
struct dentry *parent;
|
|
struct inode *inode = NULL;
|
|
int error;
|
|
struct nfs_fh fhandle;
|
|
struct nfs_fattr fattr;
|
|
|
|
dfprintk(VFS, "NFS: lookup(%s/%s)\n",
|
|
dentry->d_parent->d_name.name, dentry->d_name.name);
|
|
nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
|
|
|
|
res = ERR_PTR(-ENAMETOOLONG);
|
|
if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
|
|
goto out;
|
|
|
|
res = ERR_PTR(-ENOMEM);
|
|
dentry->d_op = NFS_PROTO(dir)->dentry_ops;
|
|
|
|
/*
|
|
* If we're doing an exclusive create, optimize away the lookup
|
|
* but don't hash the dentry.
|
|
*/
|
|
if (nfs_is_exclusive_create(dir, nd)) {
|
|
d_instantiate(dentry, NULL);
|
|
res = NULL;
|
|
goto out;
|
|
}
|
|
|
|
parent = dentry->d_parent;
|
|
/* Protect against concurrent sillydeletes */
|
|
nfs_block_sillyrename(parent);
|
|
error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
|
|
if (error == -ENOENT)
|
|
goto no_entry;
|
|
if (error < 0) {
|
|
res = ERR_PTR(error);
|
|
goto out_unblock_sillyrename;
|
|
}
|
|
inode = nfs_fhget(dentry->d_sb, &fhandle, &fattr);
|
|
res = (struct dentry *)inode;
|
|
if (IS_ERR(res))
|
|
goto out_unblock_sillyrename;
|
|
|
|
no_entry:
|
|
res = d_materialise_unique(dentry, inode);
|
|
if (res != NULL) {
|
|
if (IS_ERR(res))
|
|
goto out_unblock_sillyrename;
|
|
dentry = res;
|
|
}
|
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
|
|
out_unblock_sillyrename:
|
|
nfs_unblock_sillyrename(parent);
|
|
out:
|
|
return res;
|
|
}
|
|
|
|
#ifdef CONFIG_NFS_V4
|
|
static int nfs_open_revalidate(struct dentry *, struct nameidata *);
|
|
|
|
const struct dentry_operations nfs4_dentry_operations = {
|
|
.d_revalidate = nfs_open_revalidate,
|
|
.d_delete = nfs_dentry_delete,
|
|
.d_iput = nfs_dentry_iput,
|
|
};
|
|
|
|
/*
|
|
* Use intent information to determine whether we need to substitute
|
|
* the NFSv4-style stateful OPEN for the LOOKUP call
|
|
*/
|
|
static int is_atomic_open(struct nameidata *nd)
|
|
{
|
|
if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0)
|
|
return 0;
|
|
/* NFS does not (yet) have a stateful open for directories */
|
|
if (nd->flags & LOOKUP_DIRECTORY)
|
|
return 0;
|
|
/* Are we trying to write to a read only partition? */
|
|
if (__mnt_is_readonly(nd->path.mnt) &&
|
|
(nd->intent.open.flags & (O_CREAT|O_TRUNC|FMODE_WRITE)))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
|
|
{
|
|
struct dentry *res = NULL;
|
|
int error;
|
|
|
|
dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n",
|
|
dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
|
|
|
|
/* Check that we are indeed trying to open this file */
|
|
if (!is_atomic_open(nd))
|
|
goto no_open;
|
|
|
|
if (dentry->d_name.len > NFS_SERVER(dir)->namelen) {
|
|
res = ERR_PTR(-ENAMETOOLONG);
|
|
goto out;
|
|
}
|
|
dentry->d_op = NFS_PROTO(dir)->dentry_ops;
|
|
|
|
/* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash
|
|
* the dentry. */
|
|
if (nd->flags & LOOKUP_EXCL) {
|
|
d_instantiate(dentry, NULL);
|
|
goto out;
|
|
}
|
|
|
|
/* Open the file on the server */
|
|
res = nfs4_atomic_open(dir, dentry, nd);
|
|
if (IS_ERR(res)) {
|
|
error = PTR_ERR(res);
|
|
switch (error) {
|
|
/* Make a negative dentry */
|
|
case -ENOENT:
|
|
res = NULL;
|
|
goto out;
|
|
/* This turned out not to be a regular file */
|
|
case -ENOTDIR:
|
|
goto no_open;
|
|
case -ELOOP:
|
|
if (!(nd->intent.open.flags & O_NOFOLLOW))
|
|
goto no_open;
|
|
/* case -EISDIR: */
|
|
/* case -EINVAL: */
|
|
default:
|
|
goto out;
|
|
}
|
|
} else if (res != NULL)
|
|
dentry = res;
|
|
out:
|
|
return res;
|
|
no_open:
|
|
return nfs_lookup(dir, dentry, nd);
|
|
}
|
|
|
|
static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
|
|
{
|
|
struct dentry *parent = NULL;
|
|
struct inode *inode = dentry->d_inode;
|
|
struct inode *dir;
|
|
int openflags, ret = 0;
|
|
|
|
if (!is_atomic_open(nd))
|
|
goto no_open;
|
|
parent = dget_parent(dentry);
|
|
dir = parent->d_inode;
|
|
/* We can't create new files in nfs_open_revalidate(), so we
|
|
* optimize away revalidation of negative dentries.
|
|
*/
|
|
if (inode == NULL) {
|
|
if (!nfs_neg_need_reval(dir, dentry, nd))
|
|
ret = 1;
|
|
goto out;
|
|
}
|
|
|
|
/* NFS only supports OPEN on regular files */
|
|
if (!S_ISREG(inode->i_mode))
|
|
goto no_open_dput;
|
|
openflags = nd->intent.open.flags;
|
|
/* We cannot do exclusive creation on a positive dentry */
|
|
if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
|
|
goto no_open_dput;
|
|
/* We can't create new files, or truncate existing ones here */
|
|
openflags &= ~(O_CREAT|O_TRUNC);
|
|
|
|
/*
|
|
* Note: we're not holding inode->i_mutex and so may be racing with
|
|
* operations that change the directory. We therefore save the
|
|
* change attribute *before* we do the RPC call.
|
|
*/
|
|
ret = nfs4_open_revalidate(dir, dentry, openflags, nd);
|
|
out:
|
|
dput(parent);
|
|
if (!ret)
|
|
d_drop(dentry);
|
|
return ret;
|
|
no_open_dput:
|
|
dput(parent);
|
|
no_open:
|
|
return nfs_lookup_revalidate(dentry, nd);
|
|
}
|
|
#endif /* CONFIG_NFSV4 */
|
|
|
|
static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc)
|
|
{
|
|
struct dentry *parent = desc->file->f_path.dentry;
|
|
struct inode *dir = parent->d_inode;
|
|
struct nfs_entry *entry = desc->entry;
|
|
struct dentry *dentry, *alias;
|
|
struct qstr name = {
|
|
.name = entry->name,
|
|
.len = entry->len,
|
|
};
|
|
struct inode *inode;
|
|
unsigned long verf = nfs_save_change_attribute(dir);
|
|
|
|
switch (name.len) {
|
|
case 2:
|
|
if (name.name[0] == '.' && name.name[1] == '.')
|
|
return dget_parent(parent);
|
|
break;
|
|
case 1:
|
|
if (name.name[0] == '.')
|
|
return dget(parent);
|
|
}
|
|
|
|
spin_lock(&dir->i_lock);
|
|
if (NFS_I(dir)->cache_validity & NFS_INO_INVALID_DATA) {
|
|
spin_unlock(&dir->i_lock);
|
|
return NULL;
|
|
}
|
|
spin_unlock(&dir->i_lock);
|
|
|
|
name.hash = full_name_hash(name.name, name.len);
|
|
dentry = d_lookup(parent, &name);
|
|
if (dentry != NULL) {
|
|
/* Is this a positive dentry that matches the readdir info? */
|
|
if (dentry->d_inode != NULL &&
|
|
(NFS_FILEID(dentry->d_inode) == entry->ino ||
|
|
d_mountpoint(dentry))) {
|
|
if (!desc->plus || entry->fh->size == 0)
|
|
return dentry;
|
|
if (nfs_compare_fh(NFS_FH(dentry->d_inode),
|
|
entry->fh) == 0)
|
|
goto out_renew;
|
|
}
|
|
/* No, so d_drop to allow one to be created */
|
|
d_drop(dentry);
|
|
dput(dentry);
|
|
}
|
|
if (!desc->plus || !(entry->fattr->valid & NFS_ATTR_FATTR))
|
|
return NULL;
|
|
if (name.len > NFS_SERVER(dir)->namelen)
|
|
return NULL;
|
|
/* Note: caller is already holding the dir->i_mutex! */
|
|
dentry = d_alloc(parent, &name);
|
|
if (dentry == NULL)
|
|
return NULL;
|
|
dentry->d_op = NFS_PROTO(dir)->dentry_ops;
|
|
inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr);
|
|
if (IS_ERR(inode)) {
|
|
dput(dentry);
|
|
return NULL;
|
|
}
|
|
|
|
alias = d_materialise_unique(dentry, inode);
|
|
if (alias != NULL) {
|
|
dput(dentry);
|
|
if (IS_ERR(alias))
|
|
return NULL;
|
|
dentry = alias;
|
|
}
|
|
|
|
out_renew:
|
|
nfs_set_verifier(dentry, verf);
|
|
return dentry;
|
|
}
|
|
|
|
/*
|
|
* Code common to create, mkdir, and mknod.
|
|
*/
|
|
int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
|
|
struct nfs_fattr *fattr)
|
|
{
|
|
struct dentry *parent = dget_parent(dentry);
|
|
struct inode *dir = parent->d_inode;
|
|
struct inode *inode;
|
|
int error = -EACCES;
|
|
|
|
d_drop(dentry);
|
|
|
|
/* We may have been initialized further down */
|
|
if (dentry->d_inode)
|
|
goto out;
|
|
if (fhandle->size == 0) {
|
|
error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
|
|
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);
|
|
if (error < 0)
|
|
goto out_error;
|
|
}
|
|
inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
|
|
error = PTR_ERR(inode);
|
|
if (IS_ERR(inode))
|
|
goto out_error;
|
|
d_add(dentry, inode);
|
|
out:
|
|
dput(parent);
|
|
return 0;
|
|
out_error:
|
|
nfs_mark_for_revalidate(dir);
|
|
dput(parent);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
static int nfs_create(struct inode *dir, struct dentry *dentry, int mode,
|
|
struct nameidata *nd)
|
|
{
|
|
struct iattr attr;
|
|
int error;
|
|
int open_flags = 0;
|
|
|
|
dfprintk(VFS, "NFS: create(%s/%ld), %s\n",
|
|
dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
|
|
|
|
attr.ia_mode = mode;
|
|
attr.ia_valid = ATTR_MODE;
|
|
|
|
if ((nd->flags & LOOKUP_CREATE) != 0)
|
|
open_flags = nd->intent.open.flags;
|
|
|
|
error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, nd);
|
|
if (error != 0)
|
|
goto out_err;
|
|
return 0;
|
|
out_err:
|
|
d_drop(dentry);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* See comments for nfs_proc_create regarding failed operations.
|
|
*/
|
|
static int
|
|
nfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
|
|
{
|
|
struct iattr attr;
|
|
int status;
|
|
|
|
dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n",
|
|
dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
|
|
|
|
if (!new_valid_dev(rdev))
|
|
return -EINVAL;
|
|
|
|
attr.ia_mode = mode;
|
|
attr.ia_valid = ATTR_MODE;
|
|
|
|
status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev);
|
|
if (status != 0)
|
|
goto out_err;
|
|
return 0;
|
|
out_err:
|
|
d_drop(dentry);
|
|
return status;
|
|
}
|
|
|
|
/*
|
|
* See comments for nfs_proc_create regarding failed operations.
|
|
*/
|
|
static int nfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
|
|
{
|
|
struct iattr attr;
|
|
int error;
|
|
|
|
dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n",
|
|
dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
|
|
|
|
attr.ia_valid = ATTR_MODE;
|
|
attr.ia_mode = mode | S_IFDIR;
|
|
|
|
error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr);
|
|
if (error != 0)
|
|
goto out_err;
|
|
return 0;
|
|
out_err:
|
|
d_drop(dentry);
|
|
return error;
|
|
}
|
|
|
|
static void nfs_dentry_handle_enoent(struct dentry *dentry)
|
|
{
|
|
if (dentry->d_inode != NULL && !d_unhashed(dentry))
|
|
d_delete(dentry);
|
|
}
|
|
|
|
static int nfs_rmdir(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
int error;
|
|
|
|
dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n",
|
|
dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
|
|
|
|
error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
|
|
/* Ensure the VFS deletes this inode */
|
|
if (error == 0 && dentry->d_inode != NULL)
|
|
clear_nlink(dentry->d_inode);
|
|
else if (error == -ENOENT)
|
|
nfs_dentry_handle_enoent(dentry);
|
|
|
|
return error;
|
|
}
|
|
|
|
static int nfs_sillyrename(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
static unsigned int sillycounter;
|
|
const int fileidsize = sizeof(NFS_FILEID(dentry->d_inode))*2;
|
|
const int countersize = sizeof(sillycounter)*2;
|
|
const int slen = sizeof(".nfs")+fileidsize+countersize-1;
|
|
char silly[slen+1];
|
|
struct qstr qsilly;
|
|
struct dentry *sdentry;
|
|
int error = -EIO;
|
|
|
|
dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n",
|
|
dentry->d_parent->d_name.name, dentry->d_name.name,
|
|
atomic_read(&dentry->d_count));
|
|
nfs_inc_stats(dir, NFSIOS_SILLYRENAME);
|
|
|
|
/*
|
|
* We don't allow a dentry to be silly-renamed twice.
|
|
*/
|
|
error = -EBUSY;
|
|
if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
|
|
goto out;
|
|
|
|
sprintf(silly, ".nfs%*.*Lx",
|
|
fileidsize, fileidsize,
|
|
(unsigned long long)NFS_FILEID(dentry->d_inode));
|
|
|
|
/* Return delegation in anticipation of the rename */
|
|
nfs_inode_return_delegation(dentry->d_inode);
|
|
|
|
sdentry = NULL;
|
|
do {
|
|
char *suffix = silly + slen - countersize;
|
|
|
|
dput(sdentry);
|
|
sillycounter++;
|
|
sprintf(suffix, "%*.*x", countersize, countersize, sillycounter);
|
|
|
|
dfprintk(VFS, "NFS: trying to rename %s to %s\n",
|
|
dentry->d_name.name, silly);
|
|
|
|
sdentry = lookup_one_len(silly, dentry->d_parent, slen);
|
|
/*
|
|
* N.B. Better to return EBUSY here ... it could be
|
|
* dangerous to delete the file while it's in use.
|
|
*/
|
|
if (IS_ERR(sdentry))
|
|
goto out;
|
|
} while(sdentry->d_inode != NULL); /* need negative lookup */
|
|
|
|
qsilly.name = silly;
|
|
qsilly.len = strlen(silly);
|
|
if (dentry->d_inode) {
|
|
error = NFS_PROTO(dir)->rename(dir, &dentry->d_name,
|
|
dir, &qsilly);
|
|
nfs_mark_for_revalidate(dentry->d_inode);
|
|
} else
|
|
error = NFS_PROTO(dir)->rename(dir, &dentry->d_name,
|
|
dir, &qsilly);
|
|
if (!error) {
|
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
|
|
d_move(dentry, sdentry);
|
|
error = nfs_async_unlink(dir, dentry);
|
|
/* If we return 0 we don't unlink */
|
|
}
|
|
dput(sdentry);
|
|
out:
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* 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 = dentry->d_parent->d_inode;
|
|
struct inode *inode = dentry->d_inode;
|
|
int error = -EBUSY;
|
|
|
|
dfprintk(VFS, "NFS: safe_remove(%s/%s)\n",
|
|
dentry->d_parent->d_name.name, dentry->d_name.name);
|
|
|
|
/* If the dentry was sillyrenamed, we simply call d_delete() */
|
|
if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
|
|
error = 0;
|
|
goto out;
|
|
}
|
|
|
|
if (inode != NULL) {
|
|
nfs_inode_return_delegation(inode);
|
|
error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
|
|
/* The VFS may want to delete this inode */
|
|
if (error == 0)
|
|
nfs_drop_nlink(inode);
|
|
nfs_mark_for_revalidate(inode);
|
|
} else
|
|
error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
|
|
if (error == -ENOENT)
|
|
nfs_dentry_handle_enoent(dentry);
|
|
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.
|
|
*/
|
|
static int nfs_unlink(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
int error;
|
|
int need_rehash = 0;
|
|
|
|
dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id,
|
|
dir->i_ino, dentry->d_name.name);
|
|
|
|
spin_lock(&dcache_lock);
|
|
spin_lock(&dentry->d_lock);
|
|
if (atomic_read(&dentry->d_count) > 1) {
|
|
spin_unlock(&dentry->d_lock);
|
|
spin_unlock(&dcache_lock);
|
|
/* Start asynchronous writeout of the inode */
|
|
write_inode_now(dentry->d_inode, 0);
|
|
error = nfs_sillyrename(dir, dentry);
|
|
return error;
|
|
}
|
|
if (!d_unhashed(dentry)) {
|
|
__d_drop(dentry);
|
|
need_rehash = 1;
|
|
}
|
|
spin_unlock(&dentry->d_lock);
|
|
spin_unlock(&dcache_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);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
static int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
|
|
{
|
|
struct pagevec lru_pvec;
|
|
struct page *page;
|
|
char *kaddr;
|
|
struct iattr attr;
|
|
unsigned int pathlen = strlen(symname);
|
|
int error;
|
|
|
|
dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id,
|
|
dir->i_ino, dentry->d_name.name, symname);
|
|
|
|
if (pathlen > PAGE_SIZE)
|
|
return -ENAMETOOLONG;
|
|
|
|
attr.ia_mode = S_IFLNK | S_IRWXUGO;
|
|
attr.ia_valid = ATTR_MODE;
|
|
|
|
page = alloc_page(GFP_HIGHUSER);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
|
|
kaddr = kmap_atomic(page, KM_USER0);
|
|
memcpy(kaddr, symname, pathlen);
|
|
if (pathlen < PAGE_SIZE)
|
|
memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
|
|
error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr);
|
|
if (error != 0) {
|
|
dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s) error %d\n",
|
|
dir->i_sb->s_id, dir->i_ino,
|
|
dentry->d_name.name, 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.
|
|
*/
|
|
pagevec_init(&lru_pvec, 0);
|
|
if (!add_to_page_cache(page, dentry->d_inode->i_mapping, 0,
|
|
GFP_KERNEL)) {
|
|
pagevec_add(&lru_pvec, page);
|
|
pagevec_lru_add_file(&lru_pvec);
|
|
SetPageUptodate(page);
|
|
unlock_page(page);
|
|
} else
|
|
__free_page(page);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
|
|
{
|
|
struct inode *inode = old_dentry->d_inode;
|
|
int error;
|
|
|
|
dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n",
|
|
old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
|
|
dentry->d_parent->d_name.name, dentry->d_name.name);
|
|
|
|
nfs_inode_return_delegation(inode);
|
|
|
|
d_drop(dentry);
|
|
error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
|
|
if (error == 0) {
|
|
atomic_inc(&inode->i_count);
|
|
d_add(dentry, inode);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
|
|
struct inode *new_dir, struct dentry *new_dentry)
|
|
{
|
|
struct inode *old_inode = old_dentry->d_inode;
|
|
struct inode *new_inode = new_dentry->d_inode;
|
|
struct dentry *dentry = NULL, *rehash = NULL;
|
|
int error = -EBUSY;
|
|
|
|
dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n",
|
|
old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
|
|
new_dentry->d_parent->d_name.name, new_dentry->d_name.name,
|
|
atomic_read(&new_dentry->d_count));
|
|
|
|
/*
|
|
* 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 (atomic_read(&new_dentry->d_count) > 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;
|
|
new_inode = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* ... prune child dentries and writebacks if needed.
|
|
*/
|
|
if (atomic_read(&old_dentry->d_count) > 1) {
|
|
if (S_ISREG(old_inode->i_mode))
|
|
nfs_wb_all(old_inode);
|
|
shrink_dcache_parent(old_dentry);
|
|
}
|
|
nfs_inode_return_delegation(old_inode);
|
|
|
|
if (new_inode != NULL)
|
|
nfs_inode_return_delegation(new_inode);
|
|
|
|
error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name,
|
|
new_dir, &new_dentry->d_name);
|
|
nfs_mark_for_revalidate(old_inode);
|
|
out:
|
|
if (rehash)
|
|
d_rehash(rehash);
|
|
if (!error) {
|
|
if (new_inode != NULL)
|
|
nfs_drop_nlink(new_inode);
|
|
d_move(old_dentry, new_dentry);
|
|
nfs_set_verifier(new_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;
|
|
}
|
|
|
|
static DEFINE_SPINLOCK(nfs_access_lru_lock);
|
|
static LIST_HEAD(nfs_access_lru_list);
|
|
static atomic_long_t nfs_access_nr_entries;
|
|
|
|
static void nfs_access_free_entry(struct nfs_access_entry *entry)
|
|
{
|
|
put_rpccred(entry->cred);
|
|
kfree(entry);
|
|
smp_mb__before_atomic_dec();
|
|
atomic_long_dec(&nfs_access_nr_entries);
|
|
smp_mb__after_atomic_dec();
|
|
}
|
|
|
|
int nfs_access_cache_shrinker(int nr_to_scan, gfp_t gfp_mask)
|
|
{
|
|
LIST_HEAD(head);
|
|
struct nfs_inode *nfsi;
|
|
struct nfs_access_entry *cache;
|
|
|
|
restart:
|
|
spin_lock(&nfs_access_lru_lock);
|
|
list_for_each_entry(nfsi, &nfs_access_lru_list, access_cache_inode_lru) {
|
|
struct rw_semaphore *s_umount;
|
|
struct inode *inode;
|
|
|
|
if (nr_to_scan-- == 0)
|
|
break;
|
|
s_umount = &nfsi->vfs_inode.i_sb->s_umount;
|
|
if (!down_read_trylock(s_umount))
|
|
continue;
|
|
inode = igrab(&nfsi->vfs_inode);
|
|
if (inode == NULL) {
|
|
up_read(s_umount);
|
|
continue;
|
|
}
|
|
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);
|
|
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);
|
|
clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
|
|
}
|
|
spin_unlock(&inode->i_lock);
|
|
spin_unlock(&nfs_access_lru_lock);
|
|
iput(inode);
|
|
up_read(s_umount);
|
|
goto restart;
|
|
}
|
|
spin_unlock(&nfs_access_lru_lock);
|
|
while (!list_empty(&head)) {
|
|
cache = list_entry(head.next, struct nfs_access_entry, lru);
|
|
list_del(&cache->lru);
|
|
nfs_access_free_entry(cache);
|
|
}
|
|
return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure;
|
|
}
|
|
|
|
static void __nfs_access_zap_cache(struct inode *inode)
|
|
{
|
|
struct nfs_inode *nfsi = NFS_I(inode);
|
|
struct rb_root *root_node = &nfsi->access_cache;
|
|
struct rb_node *n, *dispose = NULL;
|
|
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_del(&entry->lru);
|
|
n->rb_left = dispose;
|
|
dispose = n;
|
|
}
|
|
nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
|
|
spin_unlock(&inode->i_lock);
|
|
|
|
/* Now kill them all! */
|
|
while (dispose != NULL) {
|
|
n = dispose;
|
|
dispose = n->rb_left;
|
|
nfs_access_free_entry(rb_entry(n, struct nfs_access_entry, rb_node));
|
|
}
|
|
}
|
|
|
|
void nfs_access_zap_cache(struct inode *inode)
|
|
{
|
|
/* Remove from global LRU init */
|
|
if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) {
|
|
spin_lock(&nfs_access_lru_lock);
|
|
list_del_init(&NFS_I(inode)->access_cache_inode_lru);
|
|
spin_unlock(&nfs_access_lru_lock);
|
|
}
|
|
|
|
spin_lock(&inode->i_lock);
|
|
/* This will release the spinlock */
|
|
__nfs_access_zap_cache(inode);
|
|
}
|
|
|
|
static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred)
|
|
{
|
|
struct rb_node *n = NFS_I(inode)->access_cache.rb_node;
|
|
struct nfs_access_entry *entry;
|
|
|
|
while (n != NULL) {
|
|
entry = rb_entry(n, struct nfs_access_entry, rb_node);
|
|
|
|
if (cred < entry->cred)
|
|
n = n->rb_left;
|
|
else if (cred > entry->cred)
|
|
n = n->rb_right;
|
|
else
|
|
return entry;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
|
|
{
|
|
struct nfs_inode *nfsi = NFS_I(inode);
|
|
struct nfs_access_entry *cache;
|
|
int err = -ENOENT;
|
|
|
|
spin_lock(&inode->i_lock);
|
|
if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
|
|
goto out_zap;
|
|
cache = nfs_access_search_rbtree(inode, cred);
|
|
if (cache == NULL)
|
|
goto out;
|
|
if (!nfs_have_delegation(inode, FMODE_READ) &&
|
|
!time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo))
|
|
goto out_stale;
|
|
res->jiffies = cache->jiffies;
|
|
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_stale:
|
|
rb_erase(&cache->rb_node, &nfsi->access_cache);
|
|
list_del(&cache->lru);
|
|
spin_unlock(&inode->i_lock);
|
|
nfs_access_free_entry(cache);
|
|
return -ENOENT;
|
|
out_zap:
|
|
/* This will release the spinlock */
|
|
__nfs_access_zap_cache(inode);
|
|
return -ENOENT;
|
|
}
|
|
|
|
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;
|
|
|
|
spin_lock(&inode->i_lock);
|
|
while (*p != NULL) {
|
|
parent = *p;
|
|
entry = rb_entry(parent, struct nfs_access_entry, rb_node);
|
|
|
|
if (set->cred < entry->cred)
|
|
p = &parent->rb_left;
|
|
else if (set->cred > entry->cred)
|
|
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);
|
|
}
|
|
|
|
static 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->jiffies = set->jiffies;
|
|
cache->cred = get_rpccred(set->cred);
|
|
cache->mask = set->mask;
|
|
|
|
nfs_access_add_rbtree(inode, cache);
|
|
|
|
/* Update accounting */
|
|
smp_mb__before_atomic_inc();
|
|
atomic_long_inc(&nfs_access_nr_entries);
|
|
smp_mb__after_atomic_inc();
|
|
|
|
/* Add inode to global LRU list */
|
|
if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) {
|
|
spin_lock(&nfs_access_lru_lock);
|
|
list_add_tail(&NFS_I(inode)->access_cache_inode_lru, &nfs_access_lru_list);
|
|
spin_unlock(&nfs_access_lru_lock);
|
|
}
|
|
}
|
|
|
|
static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask)
|
|
{
|
|
struct nfs_access_entry cache;
|
|
int status;
|
|
|
|
status = nfs_access_get_cached(inode, cred, &cache);
|
|
if (status == 0)
|
|
goto out;
|
|
|
|
/* Be clever: ask server to check for all possible rights */
|
|
cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ;
|
|
cache.cred = cred;
|
|
cache.jiffies = jiffies;
|
|
status = NFS_PROTO(inode)->access(inode, &cache);
|
|
if (status != 0) {
|
|
if (status == -ESTALE) {
|
|
nfs_zap_caches(inode);
|
|
if (!S_ISDIR(inode->i_mode))
|
|
set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
|
|
}
|
|
return status;
|
|
}
|
|
nfs_access_add_cache(inode, &cache);
|
|
out:
|
|
if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
|
|
return 0;
|
|
return -EACCES;
|
|
}
|
|
|
|
static int nfs_open_permission_mask(int openflags)
|
|
{
|
|
int mask = 0;
|
|
|
|
if (openflags & FMODE_READ)
|
|
mask |= MAY_READ;
|
|
if (openflags & FMODE_WRITE)
|
|
mask |= MAY_WRITE;
|
|
if (openflags & FMODE_EXEC)
|
|
mask |= MAY_EXEC;
|
|
return mask;
|
|
}
|
|
|
|
int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags)
|
|
{
|
|
return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags));
|
|
}
|
|
|
|
int nfs_permission(struct inode *inode, int mask)
|
|
{
|
|
struct rpc_cred *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)
|
|
goto force_lookup;
|
|
|
|
switch (inode->i_mode & S_IFMT) {
|
|
case S_IFLNK:
|
|
goto out;
|
|
case S_IFREG:
|
|
/* NFSv4 has atomic_open... */
|
|
if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN)
|
|
&& (mask & MAY_OPEN)
|
|
&& !(mask & MAY_EXEC))
|
|
goto out;
|
|
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;
|
|
|
|
cred = rpc_lookup_cred();
|
|
if (!IS_ERR(cred)) {
|
|
res = nfs_do_access(inode, cred, mask);
|
|
put_rpccred(cred);
|
|
} else
|
|
res = PTR_ERR(cred);
|
|
out:
|
|
if (!res && (mask & MAY_EXEC) && !execute_ok(inode))
|
|
res = -EACCES;
|
|
|
|
dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n",
|
|
inode->i_sb->s_id, inode->i_ino, mask, res);
|
|
return res;
|
|
out_notsup:
|
|
res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
|
|
if (res == 0)
|
|
res = generic_permission(inode, mask, NULL);
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Local variables:
|
|
* version-control: t
|
|
* kept-new-versions: 5
|
|
* End:
|
|
*/
|