| /* |
| * linux/fs/nfs/dir.c |
| * |
| * Copyright (C) 1992 Rick Sladkey |
| * |
| * nfs directory handling functions |
| * |
| * 10 Apr 1996 Added silly rename for unlink --okir |
| * 28 Sep 1996 Improved directory cache --okir |
| * 23 Aug 1997 Claus Heine claus@momo.math.rwth-aachen.de |
| * Re-implemented silly rename for unlink, newly implemented |
| * silly rename for nfs_rename() following the suggestions |
| * of Olaf Kirch (okir) found in this file. |
| * Following Linus comments on my original hack, this version |
| * depends only on the dcache stuff and doesn't touch the inode |
| * layer (iput() and friends). |
| * 6 Jun 1999 Cache readdir lookups in the page cache. -DaveM |
| */ |
| |
| #include <linux/time.h> |
| #include <linux/errno.h> |
| #include <linux/stat.h> |
| #include <linux/fcntl.h> |
| #include <linux/string.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/mm.h> |
| #include <linux/sunrpc/clnt.h> |
| #include <linux/nfs_fs.h> |
| #include <linux/nfs_mount.h> |
| #include <linux/pagemap.h> |
| #include <linux/pagevec.h> |
| #include <linux/namei.h> |
| #include <linux/mount.h> |
| #include <linux/sched.h> |
| #include <linux/kmemleak.h> |
| #include <linux/xattr.h> |
| |
| #include "delegation.h" |
| #include "iostat.h" |
| #include "internal.h" |
| #include "fscache.h" |
| |
| /* #define NFS_DEBUG_VERBOSE 1 */ |
| |
| static int nfs_opendir(struct inode *, struct file *); |
| static int nfs_closedir(struct inode *, struct file *); |
| static int nfs_readdir(struct file *, void *, filldir_t); |
| static struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int); |
| static int nfs_create(struct inode *, struct dentry *, umode_t, struct nameidata *); |
| static int nfs_mkdir(struct inode *, struct dentry *, umode_t); |
| static int nfs_rmdir(struct inode *, struct dentry *); |
| static int nfs_unlink(struct inode *, struct dentry *); |
| static int nfs_symlink(struct inode *, struct dentry *, const char *); |
| static int nfs_link(struct dentry *, struct inode *, struct dentry *); |
| static int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t); |
| static int nfs_rename(struct inode *, struct dentry *, |
| struct inode *, struct dentry *); |
| static int nfs_fsync_dir(struct file *, loff_t, loff_t, int); |
| static loff_t nfs_llseek_dir(struct file *, loff_t, int); |
| static void nfs_readdir_clear_array(struct page*); |
| |
| const struct file_operations nfs_dir_operations = { |
| .llseek = nfs_llseek_dir, |
| .read = generic_read_dir, |
| .readdir = nfs_readdir, |
| .open = nfs_opendir, |
| .release = nfs_closedir, |
| .fsync = nfs_fsync_dir, |
| }; |
| |
| const struct inode_operations nfs_dir_inode_operations = { |
| .create = nfs_create, |
| .lookup = nfs_lookup, |
| .link = nfs_link, |
| .unlink = nfs_unlink, |
| .symlink = nfs_symlink, |
| .mkdir = nfs_mkdir, |
| .rmdir = nfs_rmdir, |
| .mknod = nfs_mknod, |
| .rename = nfs_rename, |
| .permission = nfs_permission, |
| .getattr = nfs_getattr, |
| .setattr = nfs_setattr, |
| }; |
| |
| const struct address_space_operations nfs_dir_aops = { |
| .freepage = nfs_readdir_clear_array, |
| }; |
| |
| #ifdef CONFIG_NFS_V3 |
| const struct inode_operations nfs3_dir_inode_operations = { |
| .create = nfs_create, |
| .lookup = nfs_lookup, |
| .link = nfs_link, |
| .unlink = nfs_unlink, |
| .symlink = nfs_symlink, |
| .mkdir = nfs_mkdir, |
| .rmdir = nfs_rmdir, |
| .mknod = nfs_mknod, |
| .rename = nfs_rename, |
| .permission = nfs_permission, |
| .getattr = nfs_getattr, |
| .setattr = nfs_setattr, |
| .listxattr = nfs3_listxattr, |
| .getxattr = nfs3_getxattr, |
| .setxattr = nfs3_setxattr, |
| .removexattr = nfs3_removexattr, |
| }; |
| #endif /* CONFIG_NFS_V3 */ |
| |
| #ifdef CONFIG_NFS_V4 |
| |
| static int nfs_atomic_open(struct inode *, struct dentry *, |
| struct file *, unsigned, umode_t, |
| int *); |
| const struct inode_operations nfs4_dir_inode_operations = { |
| .create = nfs_create, |
| .lookup = nfs_lookup, |
| .atomic_open = nfs_atomic_open, |
| .link = nfs_link, |
| .unlink = nfs_unlink, |
| .symlink = nfs_symlink, |
| .mkdir = nfs_mkdir, |
| .rmdir = nfs_rmdir, |
| .mknod = nfs_mknod, |
| .rename = nfs_rename, |
| .permission = nfs_permission, |
| .getattr = nfs_getattr, |
| .setattr = nfs_setattr, |
| .getxattr = generic_getxattr, |
| .setxattr = generic_setxattr, |
| .listxattr = generic_listxattr, |
| .removexattr = generic_removexattr, |
| }; |
| |
| #endif /* CONFIG_NFS_V4 */ |
| |
| static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct inode *dir, struct rpc_cred *cred) |
| { |
| struct nfs_open_dir_context *ctx; |
| ctx = kmalloc(sizeof(*ctx), GFP_KERNEL); |
| if (ctx != NULL) { |
| ctx->duped = 0; |
| ctx->attr_gencount = NFS_I(dir)->attr_gencount; |
| ctx->dir_cookie = 0; |
| ctx->dup_cookie = 0; |
| ctx->cred = get_rpccred(cred); |
| return ctx; |
| } |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| static void put_nfs_open_dir_context(struct nfs_open_dir_context *ctx) |
| { |
| put_rpccred(ctx->cred); |
| kfree(ctx); |
| } |
| |
| /* |
| * Open file |
| */ |
| static int |
| nfs_opendir(struct inode *inode, struct file *filp) |
| { |
| int res = 0; |
| struct nfs_open_dir_context *ctx; |
| struct rpc_cred *cred; |
| |
| dfprintk(FILE, "NFS: open dir(%s/%s)\n", |
| filp->f_path.dentry->d_parent->d_name.name, |
| filp->f_path.dentry->d_name.name); |
| |
| nfs_inc_stats(inode, NFSIOS_VFSOPEN); |
| |
| cred = rpc_lookup_cred(); |
| if (IS_ERR(cred)) |
| return PTR_ERR(cred); |
| ctx = alloc_nfs_open_dir_context(inode, cred); |
| if (IS_ERR(ctx)) { |
| res = PTR_ERR(ctx); |
| goto out; |
| } |
| filp->private_data = ctx; |
| if (filp->f_path.dentry == filp->f_path.mnt->mnt_root) { |
| /* This is a mountpoint, so d_revalidate will never |
| * have been called, so we need to refresh the |
| * inode (for close-open consistency) ourselves. |
| */ |
| __nfs_revalidate_inode(NFS_SERVER(inode), inode); |
| } |
| out: |
| put_rpccred(cred); |
| return res; |
| } |
| |
| static int |
| nfs_closedir(struct inode *inode, struct file *filp) |
| { |
| put_nfs_open_dir_context(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; |
| struct nfs_cache_array_entry array[0]; |
| }; |
| |
| typedef int (*decode_dirent_t)(struct xdr_stream *, struct nfs_entry *, int); |
| typedef struct { |
| struct file *file; |
| struct page *page; |
| unsigned long page_index; |
| u64 *dir_cookie; |
| u64 last_cookie; |
| loff_t current_index; |
| decode_dirent_t decode; |
| |
| unsigned long timestamp; |
| unsigned long gencount; |
| unsigned int cache_entry_index; |
| unsigned int plus:1; |
| unsigned int eof:1; |
| } nfs_readdir_descriptor_t; |
| |
| /* |
| * The caller is responsible for calling nfs_readdir_release_array(page) |
| */ |
| static |
| struct nfs_cache_array *nfs_readdir_get_array(struct page *page) |
| { |
| void *ptr; |
| if (page == NULL) |
| return ERR_PTR(-EIO); |
| ptr = kmap(page); |
| if (ptr == NULL) |
| return ERR_PTR(-ENOMEM); |
| return ptr; |
| } |
| |
| static |
| void nfs_readdir_release_array(struct page *page) |
| { |
| kunmap(page); |
| } |
| |
| /* |
| * we are freeing strings created by nfs_add_to_readdir_array() |
| */ |
| static |
| 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); |
| 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 |
| int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len) |
| { |
| string->len = len; |
| string->name = kmemdup(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(name, len); |
| return 0; |
| } |
| |
| static |
| int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page) |
| { |
| struct nfs_cache_array *array = nfs_readdir_get_array(page); |
| struct nfs_cache_array_entry *cache_entry; |
| int ret; |
| |
| if (IS_ERR(array)) |
| return PTR_ERR(array); |
| |
| cache_entry = &array->array[array->size]; |
| |
| /* Check that this entry lies within the page bounds */ |
| 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: |
| nfs_readdir_release_array(page); |
| return ret; |
| } |
| |
| static |
| int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc) |
| { |
| loff_t diff = desc->file->f_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; |
| desc->cache_entry_index = index; |
| return 0; |
| out_eof: |
| desc->eof = 1; |
| return -EBADCOOKIE; |
| } |
| |
| 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(desc->file->f_path.dentry->d_inode); |
| struct nfs_open_dir_context *ctx = desc->file->private_data; |
| |
| new_pos = desc->current_index + i; |
| if (ctx->attr_gencount != nfsi->attr_gencount |
| || (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))) { |
| ctx->duped = 0; |
| ctx->attr_gencount = nfsi->attr_gencount; |
| } else if (new_pos < desc->file->f_pos) { |
| if (ctx->duped > 0 |
| && ctx->dup_cookie == *desc->dir_cookie) { |
| if (printk_ratelimit()) { |
| pr_notice("NFS: directory %s/%s contains a readdir loop." |
| "Please contact your server vendor. " |
| "The file: %s has duplicate cookie %llu\n", |
| desc->file->f_dentry->d_parent->d_name.name, |
| desc->file->f_dentry->d_name.name, |
| array->array[i].string.name, |
| *desc->dir_cookie); |
| } |
| status = -ELOOP; |
| goto out; |
| } |
| ctx->dup_cookie = *desc->dir_cookie; |
| ctx->duped = -1; |
| } |
| desc->file->f_pos = 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 = 1; |
| } |
| out: |
| return status; |
| } |
| |
| static |
| int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc) |
| { |
| struct nfs_cache_array *array; |
| int status; |
| |
| array = nfs_readdir_get_array(desc->page); |
| if (IS_ERR(array)) { |
| status = PTR_ERR(array); |
| goto out; |
| } |
| |
| 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++; |
| } |
| nfs_readdir_release_array(desc->page); |
| out: |
| 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; |
| struct rpc_cred *cred = ctx->cred; |
| unsigned long timestamp, gencount; |
| int error; |
| |
| again: |
| timestamp = jiffies; |
| gencount = nfs_inc_attr_generation_counter(); |
| error = NFS_PROTO(inode)->readdir(file->f_path.dentry, 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 = 0; |
| 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) |
| { |
| int error; |
| |
| error = desc->decode(xdr, entry, desc->plus); |
| if (error) |
| return error; |
| entry->fattr->time_start = desc->timestamp; |
| entry->fattr->gencount = desc->gencount; |
| return 0; |
| } |
| |
| static |
| int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry) |
| { |
| if (dentry->d_inode == NULL) |
| goto different; |
| if (nfs_compare_fh(entry->fh, NFS_FH(dentry->d_inode)) != 0) |
| goto different; |
| return 1; |
| different: |
| return 0; |
| } |
| |
| static |
| void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry) |
| { |
| struct qstr filename = QSTR_INIT(entry->name, entry->len); |
| struct dentry *dentry; |
| struct dentry *alias; |
| struct inode *dir = parent->d_inode; |
| struct inode *inode; |
| |
| if (filename.name[0] == '.') { |
| if (filename.len == 1) |
| return; |
| if (filename.len == 2 && filename.name[1] == '.') |
| return; |
| } |
| filename.hash = full_name_hash(filename.name, filename.len); |
| |
| dentry = d_lookup(parent, &filename); |
| if (dentry != NULL) { |
| if (nfs_same_file(dentry, entry)) { |
| nfs_refresh_inode(dentry->d_inode, entry->fattr); |
| goto out; |
| } else { |
| d_drop(dentry); |
| dput(dentry); |
| } |
| } |
| |
| dentry = d_alloc(parent, &filename); |
| if (dentry == NULL) |
| return; |
| |
| inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr); |
| if (IS_ERR(inode)) |
| goto out; |
| |
| alias = d_materialise_unique(dentry, inode); |
| if (IS_ERR(alias)) |
| goto out; |
| else if (alias) { |
| nfs_set_verifier(alias, nfs_save_change_attribute(dir)); |
| dput(alias); |
| } else |
| nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
| |
| 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; |
| |
| xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen); |
| xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE); |
| |
| do { |
| status = xdr_decode(desc, entry, &stream); |
| if (status != 0) { |
| if (status == -EAGAIN) |
| status = 0; |
| break; |
| } |
| |
| count++; |
| |
| if (desc->plus != 0) |
| nfs_prime_dcache(desc->file->f_path.dentry, entry); |
| |
| status = nfs_readdir_add_to_array(entry, page); |
| if (status != 0) |
| break; |
| } while (!entry->eof); |
| |
| if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) { |
| array = nfs_readdir_get_array(page); |
| if (!IS_ERR(array)) { |
| array->eof_index = array->size; |
| status = 0; |
| nfs_readdir_release_array(page); |
| } else |
| status = PTR_ERR(array); |
| } |
| |
| put_page(scratch); |
| return status; |
| } |
| |
| static |
| void nfs_readdir_free_pagearray(struct page **pages, unsigned int npages) |
| { |
| unsigned int i; |
| for (i = 0; i < npages; i++) |
| put_page(pages[i]); |
| } |
| |
| static |
| void nfs_readdir_free_large_page(void *ptr, struct page **pages, |
| unsigned int npages) |
| { |
| nfs_readdir_free_pagearray(pages, npages); |
| } |
| |
| /* |
| * nfs_readdir_large_page will allocate pages that must be freed with a call |
| * to nfs_readdir_free_large_page |
| */ |
| static |
| int nfs_readdir_large_page(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_pagearray(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]; |
| void *pages_ptr = NULL; |
| struct nfs_entry entry; |
| struct file *file = desc->file; |
| struct nfs_cache_array *array; |
| int status = -ENOMEM; |
| unsigned int array_size = ARRAY_SIZE(pages); |
| |
| 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; |
| |
| array = nfs_readdir_get_array(page); |
| if (IS_ERR(array)) { |
| status = PTR_ERR(array); |
| goto out; |
| } |
| memset(array, 0, sizeof(struct nfs_cache_array)); |
| array->eof_index = -1; |
| |
| status = nfs_readdir_large_page(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_large_page(pages_ptr, pages, array_size); |
| out_release_array: |
| nfs_readdir_release_array(page); |
| 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(nfs_readdir_descriptor_t *desc, struct page* page) |
| { |
| struct inode *inode = desc->file->f_path.dentry->d_inode; |
| 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: |
| unlock_page(page); |
| return ret; |
| } |
| |
| static |
| void cache_page_release(nfs_readdir_descriptor_t *desc) |
| { |
| if (!desc->page->mapping) |
| nfs_readdir_clear_array(desc->page); |
| page_cache_release(desc->page); |
| desc->page = NULL; |
| } |
| |
| static |
| struct page *get_cache_page(nfs_readdir_descriptor_t *desc) |
| { |
| return read_cache_page(desc->file->f_path.dentry->d_inode->i_mapping, |
| desc->page_index, (filler_t *)nfs_readdir_filler, desc); |
| } |
| |
| /* |
| * Returns 0 if desc->dir_cookie was found on page desc->page_index |
| */ |
| static |
| int find_cache_page(nfs_readdir_descriptor_t *desc) |
| { |
| int res; |
| |
| desc->page = get_cache_page(desc); |
| if (IS_ERR(desc->page)) |
| return PTR_ERR(desc->page); |
| |
| res = nfs_readdir_search_array(desc); |
| if (res != 0) |
| 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->last_cookie = 0; |
| } |
| do { |
| res = find_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, void *dirent, |
| filldir_t filldir) |
| { |
| 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 = nfs_readdir_get_array(desc->page); |
| if (IS_ERR(array)) { |
| res = PTR_ERR(array); |
| goto out; |
| } |
| |
| for (i = desc->cache_entry_index; i < array->size; i++) { |
| struct nfs_cache_array_entry *ent; |
| |
| ent = &array->array[i]; |
| if (filldir(dirent, ent->string.name, ent->string.len, |
| file->f_pos, nfs_compat_user_ino64(ent->ino), |
| ent->d_type) < 0) { |
| desc->eof = 1; |
| break; |
| } |
| file->f_pos++; |
| if (i < (array->size-1)) |
| *desc->dir_cookie = array->array[i+1].cookie; |
| else |
| *desc->dir_cookie = array->last_cookie; |
| if (ctx->duped != 0) |
| ctx->duped = 1; |
| } |
| if (array->eof_index >= 0) |
| desc->eof = 1; |
| |
| nfs_readdir_release_array(desc->page); |
| out: |
| cache_page_release(desc); |
| 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, void *dirent, |
| filldir_t filldir) |
| { |
| struct page *page = NULL; |
| int status; |
| struct inode *inode = desc->file->f_path.dentry->d_inode; |
| 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, dirent, filldir); |
| |
| out: |
| dfprintk(DIRCACHE, "NFS: %s: returns %d\n", |
| __func__, status); |
| return status; |
| out_release: |
| cache_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_open_dir_context *dir_ctx = filp->private_data; |
| int 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 = &dir_ctx->dir_cookie; |
| desc->decode = NFS_PROTO(inode)->decode_dirent; |
| desc->plus = NFS_USE_READDIRPLUS(inode); |
| |
| nfs_block_sillyrename(dentry); |
| res = nfs_revalidate_mapping(inode, filp->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 == 0) { |
| /* Or that the server has 'lost' a cookie */ |
| res = uncached_readdir(desc, dirent, filldir); |
| 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 = 0; |
| desc->eof = 0; |
| continue; |
| } |
| if (res < 0) |
| break; |
| |
| res = nfs_do_filldir(desc, dirent, filldir); |
| if (res < 0) |
| break; |
| } while (!desc->eof); |
| out: |
| nfs_unblock_sillyrename(dentry); |
| if (res > 0) |
| res = 0; |
| dfprintk(FILE, "NFS: readdir(%s/%s) returns %d\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; |
| struct nfs_open_dir_context *dir_ctx = filp->private_data; |
| |
| 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; |
| dir_ctx->dir_cookie = 0; |
| dir_ctx->duped = 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, loff_t start, loff_t end, |
| int datasync) |
| { |
| struct dentry *dentry = filp->f_path.dentry; |
| struct inode *inode = dentry->d_inode; |
| |
| dfprintk(FILE, "NFS: fsync dir(%s/%s) datasync %d\n", |
| dentry->d_parent->d_name.name, dentry->d_name.name, |
| datasync); |
| |
| mutex_lock(&inode->i_mutex); |
| nfs_inc_stats(dentry->d_inode, NFSIOS_VFSFSYNC); |
| mutex_unlock(&inode->i_mutex); |
| 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; |
| } |
| |
| /* |
| * 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 inline |
| int nfs_lookup_verify_inode(struct inode *inode, unsigned int flags) |
| { |
| struct nfs_server *server = NFS_SERVER(inode); |
| |
| if (IS_AUTOMOUNT(inode)) |
| return 0; |
| /* VFS wants an on-the-wire revalidation */ |
| if (flags & LOOKUP_REVAL) |
| goto out_force; |
| /* This is an open(2) */ |
| if ((flags & LOOKUP_OPEN) && !(server->flags & NFS_MOUNT_NOCTO) && |
| (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))) |
| goto out_force; |
| return 0; |
| 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, |
| unsigned int flags) |
| { |
| /* Don't revalidate a negative dentry if we're creating a new file */ |
| if (flags & LOOKUP_CREATE) |
| 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, unsigned int flags) |
| { |
| struct inode *dir; |
| struct inode *inode; |
| struct dentry *parent; |
| struct nfs_fh *fhandle = NULL; |
| struct nfs_fattr *fattr = NULL; |
| int error; |
| |
| if (flags & LOOKUP_RCU) |
| return -ECHILD; |
| |
| 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, flags)) |
| 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, flags) && nfs_check_verifier(dir, dentry)) { |
| if (nfs_lookup_verify_inode(inode, flags)) |
| goto out_zap_parent; |
| goto out_valid; |
| } |
| |
| if (NFS_STALE(inode)) |
| goto out_bad; |
| |
| error = -ENOMEM; |
| fhandle = nfs_alloc_fhandle(); |
| fattr = nfs_alloc_fattr(); |
| if (fhandle == NULL || fattr == NULL) |
| goto out_error; |
| |
| error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, 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; |
| |
| nfs_free_fattr(fattr); |
| nfs_free_fhandle(fhandle); |
| 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; |
| if (dentry->d_flags & DCACHE_DISCONNECTED) |
| goto out_valid; |
| shrink_dcache_parent(dentry); |
| } |
| d_drop(dentry); |
| nfs_free_fattr(fattr); |
| nfs_free_fhandle(fhandle); |
| dput(parent); |
| dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n", |
| __func__, dentry->d_parent->d_name.name, |
| dentry->d_name.name); |
| return 0; |
| out_error: |
| nfs_free_fattr(fattr); |
| nfs_free_fhandle(fhandle); |
| dput(parent); |
| dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) lookup returned error %d\n", |
| __func__, dentry->d_parent->d_name.name, |
| dentry->d_name.name, error); |
| 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(%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); |
| } |
| |
| 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_delete = nfs_dentry_delete, |
| .d_iput = nfs_dentry_iput, |
| .d_automount = nfs_d_automount, |
| .d_release = nfs_d_release, |
| }; |
| |
| static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) |
| { |
| struct dentry *res; |
| struct dentry *parent; |
| struct inode *inode = NULL; |
| struct nfs_fh *fhandle = NULL; |
| struct nfs_fattr *fattr = NULL; |
| int error; |
| |
| 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; |
| |
| /* |
| * If we're doing an exclusive create, optimize away the lookup |
| * but don't hash the dentry. |
| */ |
| if (nfs_is_exclusive_create(dir, flags)) { |
| d_instantiate(dentry, NULL); |
| res = NULL; |
| goto out; |
| } |
| |
| res = ERR_PTR(-ENOMEM); |
| fhandle = nfs_alloc_fhandle(); |
| fattr = nfs_alloc_fattr(); |
| if (fhandle == NULL || fattr == NULL) |
| goto out; |
| |
| parent = dentry->d_parent; |
| /* Protect against concurrent sillydeletes */ |
| nfs_block_sillyrename(parent); |
| error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, 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 = ERR_CAST(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: |
| nfs_free_fattr(fattr); |
| nfs_free_fhandle(fhandle); |
| return res; |
| } |
| |
| #ifdef 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_delete = nfs_dentry_delete, |
| .d_iput = nfs_dentry_iput, |
| .d_automount = nfs_d_automount, |
| .d_release = nfs_d_release, |
| }; |
| |
| 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) |
| { |
| return alloc_nfs_open_context(dentry, flags_to_mode(open_flags)); |
| } |
| |
| static int do_open(struct inode *inode, struct file *filp) |
| { |
| nfs_fscache_set_inode_cookie(inode, filp); |
| return 0; |
| } |
| |
| static int nfs_finish_open(struct nfs_open_context *ctx, |
| struct dentry *dentry, |
| struct file *file, unsigned open_flags, |
| int *opened) |
| { |
| int err; |
| |
| if (ctx->dentry != dentry) { |
| dput(ctx->dentry); |
| ctx->dentry = dget(dentry); |
| } |
| |
| /* If the open_intent is for execute, we have an extra check to make */ |
| if (ctx->mode & FMODE_EXEC) { |
| err = nfs_may_open(dentry->d_inode, ctx->cred, open_flags); |
| if (err < 0) |
| goto out; |
| } |
| |
| err = finish_open(file, dentry, do_open, opened); |
| if (err) |
| goto out; |
| nfs_file_set_open_context(file, ctx); |
| |
| out: |
| put_nfs_open_context(ctx); |
| return err; |
| } |
| |
| static int nfs_atomic_open(struct inode *dir, struct dentry *dentry, |
| struct file *file, unsigned open_flags, |
| umode_t mode, int *opened) |
| { |
| struct nfs_open_context *ctx; |
| struct dentry *res; |
| struct iattr attr = { .ia_valid = ATTR_OPEN }; |
| struct inode *inode; |
| int err; |
| |
| /* Expect a negative dentry */ |
| BUG_ON(dentry->d_inode); |
| |
| dfprintk(VFS, "NFS: atomic_open(%s/%ld), %s\n", |
| dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); |
| |
| /* NFS only supports OPEN on regular files */ |
| if ((open_flags & O_DIRECTORY)) { |
| if (!d_unhashed(dentry)) { |
| /* |
| * Hashed negative dentry with O_DIRECTORY: dentry was |
| * revalidated and is fine, no need to perform lookup |
| * again |
| */ |
| return -ENOENT; |
| } |
| goto no_open; |
| } |
| |
| if (dentry->d_name.len > NFS_SERVER(dir)->namelen) |
| return -ENAMETOOLONG; |
| |
| if (open_flags & O_CREAT) { |
| attr.ia_valid |= ATTR_MODE; |
| attr.ia_mode = mode & ~current_umask(); |
| } |
| if (open_flags & O_TRUNC) { |
| attr.ia_valid |= ATTR_SIZE; |
| attr.ia_size = 0; |
| } |
| |
| ctx = create_nfs_open_context(dentry, open_flags); |
| err = PTR_ERR(ctx); |
| if (IS_ERR(ctx)) |
| goto out; |
| |
| nfs_block_sillyrename(dentry->d_parent); |
| inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr); |
| d_drop(dentry); |
| if (IS_ERR(inode)) { |
| nfs_unblock_sillyrename(dentry->d_parent); |
| put_nfs_open_context(ctx); |
| err = PTR_ERR(inode); |
| switch (err) { |
| case -ENOENT: |
| d_add(dentry, NULL); |
| 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; |
| } |
| res = d_add_unique(dentry, inode); |
| if (res != NULL) |
| dentry = res; |
| |
| nfs_unblock_sillyrename(dentry->d_parent); |
| nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
| |
| err = nfs_finish_open(ctx, dentry, file, open_flags, opened); |
| |
| dput(res); |
| out: |
| return err; |
| |
| no_open: |
| res = nfs_lookup(dir, dentry, 0); |
| err = PTR_ERR(res); |
| if (IS_ERR(res)) |
| goto out; |
| |
| return finish_no_open(file, res); |
| } |
| |
| static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags) |
| { |
| struct dentry *parent = NULL; |
| struct inode *inode; |
| struct inode *dir; |
| int ret = 0; |
| |
| if (flags & LOOKUP_RCU) |
| return -ECHILD; |
| |
| if (!(flags & LOOKUP_OPEN) || (flags & LOOKUP_DIRECTORY)) |
| goto no_open; |
| if (d_mountpoint(dentry)) |
| goto no_open; |
| |
| inode = dentry->d_inode; |
| 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, flags)) |
| ret = 1; |
| goto out; |
| } |
| |
| /* NFS only supports OPEN on regular files */ |
| if (!S_ISREG(inode->i_mode)) |
| goto no_open_dput; |
| /* We cannot do exclusive creation on a positive dentry */ |
| if (flags & LOOKUP_EXCL) |
| goto no_open_dput; |
| |
| /* Let f_op->open() actually open (and revalidate) the file */ |
| ret = 1; |
| |
| out: |
| dput(parent); |
| return ret; |
| |
| no_open_dput: |
| dput(parent); |
| no_open: |
| return nfs_lookup_revalidate(dentry, flags); |
| } |
| |
| #endif /* CONFIG_NFSV4 */ |
| |
| /* |
| * 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(NFS_SERVER(dir)->client, 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, |
| umode_t mode, struct nameidata *nd) |
| { |
| struct iattr attr; |
| int error; |
| int open_flags = O_CREAT|O_EXCL; |
| |
| 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 && !(nd->flags & LOOKUP_EXCL)) |
| open_flags = O_CREAT; |
| |
| error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags); |
| 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, umode_t 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, umode_t 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; |
| } |
| |
| /* |
| * 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(&dentry->d_lock); |
| if (dentry->d_count > 1) { |
| spin_unlock(&dentry->d_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); |
| 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); |
| memcpy(kaddr, symname, pathlen); |
| if (pathlen < PAGE_SIZE) |
| memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen); |
| kunmap_atomic(kaddr); |
| |
| 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) { |
| ihold(inode); |
| 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, |
| 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 (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; |
| rehash = NULL; |
| new_inode = NULL; |
| } |
| } |
| |
| 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(); |
| } |
| |
| 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); |
| } |
| } |
| |
| int nfs_access_cache_shrinker(struct shrinker *shrink, |
| struct shrink_control *sc) |
| { |
| LIST_HEAD(head); |
| struct nfs_inode *nfsi, *next; |
| struct nfs_access_entry *cache; |
| int nr_to_scan = sc->nr_to_scan; |
| gfp_t gfp_mask = sc->gfp_mask; |
| |
| if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL) |
| return (nr_to_scan == 0) ? 0 : -1; |
| |
| 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); |
| 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_clear_bit(); |
| clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags); |
| smp_mb__after_clear_bit(); |
| } |
| spin_unlock(&inode->i_lock); |
| } |
| spin_unlock(&nfs_access_lru_lock); |
| nfs_access_free_list(&head); |
| return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure; |
| } |
| |
| 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); |
| } |
| |
| 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_delegated_attributes(inode) && |
| !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: |
| spin_unlock(&inode->i_lock); |
| 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_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); |
| } |
| } |
| |
| 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 & O_ACCMODE) != O_WRONLY) |
| mask |= MAY_READ; |
| if ((openflags & O_ACCMODE) != O_RDONLY) |
| 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; |
| |
| if (mask & MAY_NOT_BLOCK) |
| return -ECHILD; |
| |
| 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: |
| /* 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); |
| goto out; |
| } |
| |
| /* |
| * Local variables: |
| * version-control: t |
| * kept-new-versions: 5 |
| * End: |
| */ |