| /* |
| * 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/smp_lock.h> |
| #include <linux/pagevec.h> |
| #include <linux/namei.h> |
| #include <linux/mount.h> |
| |
| #include "nfs4_fs.h" |
| #include "delegation.h" |
| #include "iostat.h" |
| |
| #define NFS_PARANOIA 1 |
| /* #define NFS_DEBUG_VERBOSE 1 */ |
| |
| static int nfs_opendir(struct inode *, struct file *); |
| static int nfs_readdir(struct file *, void *, filldir_t); |
| static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *); |
| static int nfs_create(struct inode *, struct dentry *, int, struct nameidata *); |
| static int nfs_mkdir(struct inode *, struct dentry *, int); |
| 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 *, int, dev_t); |
| static int nfs_rename(struct inode *, struct dentry *, |
| struct inode *, struct dentry *); |
| static int nfs_fsync_dir(struct file *, struct dentry *, int); |
| static loff_t nfs_llseek_dir(struct file *, loff_t, int); |
| |
| const struct file_operations nfs_dir_operations = { |
| .llseek = nfs_llseek_dir, |
| .read = generic_read_dir, |
| .readdir = nfs_readdir, |
| .open = nfs_opendir, |
| .release = nfs_release, |
| .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, |
| }; |
| |
| #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 struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *); |
| const struct inode_operations nfs4_dir_inode_operations = { |
| .create = nfs_create, |
| .lookup = nfs_atomic_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, |
| .getxattr = nfs4_getxattr, |
| .setxattr = nfs4_setxattr, |
| .listxattr = nfs4_listxattr, |
| }; |
| |
| #endif /* CONFIG_NFS_V4 */ |
| |
| /* |
| * Open file |
| */ |
| static int |
| nfs_opendir(struct inode *inode, struct file *filp) |
| { |
| int res; |
| |
| dfprintk(VFS, "NFS: opendir(%s/%ld)\n", |
| inode->i_sb->s_id, inode->i_ino); |
| |
| lock_kernel(); |
| /* Call generic open code in order to cache credentials */ |
| res = nfs_open(inode, filp); |
| unlock_kernel(); |
| return res; |
| } |
| |
| typedef __be32 * (*decode_dirent_t)(__be32 *, struct nfs_entry *, int); |
| typedef struct { |
| struct file *file; |
| struct page *page; |
| unsigned long page_index; |
| __be32 *ptr; |
| u64 *dir_cookie; |
| loff_t current_index; |
| struct nfs_entry *entry; |
| decode_dirent_t decode; |
| int plus; |
| int error; |
| unsigned long timestamp; |
| int timestamp_valid; |
| } nfs_readdir_descriptor_t; |
| |
| /* Now we cache directories properly, by stuffing the dirent |
| * data directly in the page cache. |
| * |
| * Inode invalidation due to refresh etc. takes care of |
| * _everything_, no sloppy entry flushing logic, no extraneous |
| * copying, network direct to page cache, the way it was meant |
| * to be. |
| * |
| * NOTE: Dirent information verification is done always by the |
| * page-in of the RPC reply, nowhere else, this simplies |
| * things substantially. |
| */ |
| static |
| int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page *page) |
| { |
| struct file *file = desc->file; |
| struct inode *inode = file->f_path.dentry->d_inode; |
| struct rpc_cred *cred = nfs_file_cred(file); |
| unsigned long timestamp; |
| int error; |
| |
| dfprintk(DIRCACHE, "NFS: %s: reading cookie %Lu into page %lu\n", |
| __FUNCTION__, (long long)desc->entry->cookie, |
| page->index); |
| |
| again: |
| timestamp = jiffies; |
| error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, desc->entry->cookie, page, |
| 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_FLAGS(inode)); |
| desc->plus = 0; |
| goto again; |
| } |
| goto error; |
| } |
| desc->timestamp = timestamp; |
| desc->timestamp_valid = 1; |
| SetPageUptodate(page); |
| spin_lock(&inode->i_lock); |
| NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME; |
| spin_unlock(&inode->i_lock); |
| /* Ensure consistent page alignment of the data. |
| * Note: assumes we have exclusive access to this mapping either |
| * through inode->i_mutex or some other mechanism. |
| */ |
| if (page->index == 0 && invalidate_inode_pages2_range(inode->i_mapping, PAGE_CACHE_SIZE, -1) < 0) { |
| /* Should never happen */ |
| nfs_zap_mapping(inode, inode->i_mapping); |
| } |
| unlock_page(page); |
| return 0; |
| error: |
| SetPageError(page); |
| unlock_page(page); |
| nfs_zap_caches(inode); |
| desc->error = error; |
| return -EIO; |
| } |
| |
| static inline |
| int dir_decode(nfs_readdir_descriptor_t *desc) |
| { |
| __be32 *p = desc->ptr; |
| p = desc->decode(p, desc->entry, desc->plus); |
| if (IS_ERR(p)) |
| return PTR_ERR(p); |
| desc->ptr = p; |
| if (desc->timestamp_valid) |
| desc->entry->fattr->time_start = desc->timestamp; |
| else |
| desc->entry->fattr->valid &= ~NFS_ATTR_FATTR; |
| return 0; |
| } |
| |
| static inline |
| void dir_page_release(nfs_readdir_descriptor_t *desc) |
| { |
| kunmap(desc->page); |
| page_cache_release(desc->page); |
| desc->page = NULL; |
| desc->ptr = NULL; |
| } |
| |
| /* |
| * Given a pointer to a buffer that has already been filled by a call |
| * to readdir, find the next entry with cookie '*desc->dir_cookie'. |
| * |
| * If the end of the buffer has been reached, return -EAGAIN, if not, |
| * return the offset within the buffer of the next entry to be |
| * read. |
| */ |
| static inline |
| int find_dirent(nfs_readdir_descriptor_t *desc) |
| { |
| struct nfs_entry *entry = desc->entry; |
| int loop_count = 0, |
| status; |
| |
| while((status = dir_decode(desc)) == 0) { |
| dfprintk(DIRCACHE, "NFS: %s: examining cookie %Lu\n", |
| __FUNCTION__, (unsigned long long)entry->cookie); |
| if (entry->prev_cookie == *desc->dir_cookie) |
| break; |
| if (loop_count++ > 200) { |
| loop_count = 0; |
| schedule(); |
| } |
| } |
| return status; |
| } |
| |
| /* |
| * Given a pointer to a buffer that has already been filled by a call |
| * to readdir, find the entry at offset 'desc->file->f_pos'. |
| * |
| * If the end of the buffer has been reached, return -EAGAIN, if not, |
| * return the offset within the buffer of the next entry to be |
| * read. |
| */ |
| static inline |
| int find_dirent_index(nfs_readdir_descriptor_t *desc) |
| { |
| struct nfs_entry *entry = desc->entry; |
| int loop_count = 0, |
| status; |
| |
| for(;;) { |
| status = dir_decode(desc); |
| if (status) |
| break; |
| |
| dfprintk(DIRCACHE, "NFS: found cookie %Lu at index %Ld\n", |
| (unsigned long long)entry->cookie, desc->current_index); |
| |
| if (desc->file->f_pos == desc->current_index) { |
| *desc->dir_cookie = entry->cookie; |
| break; |
| } |
| desc->current_index++; |
| if (loop_count++ > 200) { |
| loop_count = 0; |
| schedule(); |
| } |
| } |
| return status; |
| } |
| |
| /* |
| * Find the given page, and call find_dirent() or find_dirent_index in |
| * order to try to return the next entry. |
| */ |
| static inline |
| int find_dirent_page(nfs_readdir_descriptor_t *desc) |
| { |
| struct inode *inode = desc->file->f_path.dentry->d_inode; |
| struct page *page; |
| int status; |
| |
| dfprintk(DIRCACHE, "NFS: %s: searching page %ld for target %Lu\n", |
| __FUNCTION__, desc->page_index, |
| (long long) *desc->dir_cookie); |
| |
| /* If we find the page in the page_cache, we cannot be sure |
| * how fresh the data is, so we will ignore readdir_plus attributes. |
| */ |
| desc->timestamp_valid = 0; |
| page = read_cache_page(inode->i_mapping, desc->page_index, |
| (filler_t *)nfs_readdir_filler, desc); |
| if (IS_ERR(page)) { |
| status = PTR_ERR(page); |
| goto out; |
| } |
| if (!PageUptodate(page)) |
| goto read_error; |
| |
| /* NOTE: Someone else may have changed the READDIRPLUS flag */ |
| desc->page = page; |
| desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */ |
| if (*desc->dir_cookie != 0) |
| status = find_dirent(desc); |
| else |
| status = find_dirent_index(desc); |
| if (status < 0) |
| dir_page_release(desc); |
| out: |
| dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __FUNCTION__, status); |
| return status; |
| read_error: |
| page_cache_release(page); |
| return -EIO; |
| } |
| |
| /* |
| * Recurse through the page cache pages, and return a |
| * filled nfs_entry structure of the next directory entry if possible. |
| * |
| * The target for the search is '*desc->dir_cookie' if non-0, |
| * 'desc->file->f_pos' otherwise |
| */ |
| static inline |
| int readdir_search_pagecache(nfs_readdir_descriptor_t *desc) |
| { |
| int loop_count = 0; |
| int res; |
| |
| /* Always search-by-index from the beginning of the cache */ |
| if (*desc->dir_cookie == 0) { |
| dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for offset %Ld\n", |
| (long long)desc->file->f_pos); |
| desc->page_index = 0; |
| desc->entry->cookie = desc->entry->prev_cookie = 0; |
| desc->entry->eof = 0; |
| desc->current_index = 0; |
| } else |
| dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for cookie %Lu\n", |
| (unsigned long long)*desc->dir_cookie); |
| |
| for (;;) { |
| res = find_dirent_page(desc); |
| if (res != -EAGAIN) |
| break; |
| /* Align to beginning of next page */ |
| desc->page_index ++; |
| if (loop_count++ > 200) { |
| loop_count = 0; |
| schedule(); |
| } |
| } |
| |
| dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __FUNCTION__, res); |
| return res; |
| } |
| |
| static inline unsigned int dt_type(struct inode *inode) |
| { |
| return (inode->i_mode >> 12) & 15; |
| } |
| |
| static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc); |
| |
| /* |
| * 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; |
| struct nfs_entry *entry = desc->entry; |
| struct dentry *dentry = NULL; |
| unsigned long fileid; |
| int loop_count = 0, |
| res; |
| |
| dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling starting @ cookie %Lu\n", |
| (unsigned long long)entry->cookie); |
| |
| for(;;) { |
| unsigned d_type = DT_UNKNOWN; |
| /* Note: entry->prev_cookie contains the cookie for |
| * retrieving the current dirent on the server */ |
| fileid = nfs_fileid_to_ino_t(entry->ino); |
| |
| /* Get a dentry if we have one */ |
| if (dentry != NULL) |
| dput(dentry); |
| dentry = nfs_readdir_lookup(desc); |
| |
| /* Use readdirplus info */ |
| if (dentry != NULL && dentry->d_inode != NULL) { |
| d_type = dt_type(dentry->d_inode); |
| fileid = dentry->d_inode->i_ino; |
| } |
| |
| res = filldir(dirent, entry->name, entry->len, |
| file->f_pos, fileid, d_type); |
| if (res < 0) |
| break; |
| file->f_pos++; |
| *desc->dir_cookie = entry->cookie; |
| if (dir_decode(desc) != 0) { |
| desc->page_index ++; |
| break; |
| } |
| if (loop_count++ > 200) { |
| loop_count = 0; |
| schedule(); |
| } |
| } |
| dir_page_release(desc); |
| if (dentry != NULL) |
| dput(dentry); |
| 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 file *file = desc->file; |
| struct inode *inode = file->f_path.dentry->d_inode; |
| struct rpc_cred *cred = nfs_file_cred(file); |
| struct page *page = NULL; |
| int status; |
| unsigned long timestamp; |
| |
| 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; |
| } |
| timestamp = jiffies; |
| desc->error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, *desc->dir_cookie, |
| page, |
| NFS_SERVER(inode)->dtsize, |
| desc->plus); |
| spin_lock(&inode->i_lock); |
| NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME; |
| spin_unlock(&inode->i_lock); |
| desc->page = page; |
| desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */ |
| if (desc->error >= 0) { |
| desc->timestamp = timestamp; |
| 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", |
| __FUNCTION__, 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(VFS, "NFS: readdir(%s/%s) starting at cookie %Lu\n", |
| dentry->d_parent->d_name.name, dentry->d_name.name, |
| (long long)filp->f_pos); |
| nfs_inc_stats(inode, NFSIOS_VFSGETDENTS); |
| |
| lock_kernel(); |
| |
| res = nfs_revalidate_mapping_nolock(inode, filp->f_mapping); |
| if (res < 0) { |
| unlock_kernel(); |
| return res; |
| } |
| |
| /* |
| * 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 = &((struct nfs_open_context *)filp->private_data)->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; |
| |
| 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_FLAGS(inode)); |
| 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; |
| } |
| } |
| unlock_kernel(); |
| if (res > 0) |
| res = 0; |
| dfprintk(VFS, "NFS: readdir(%s/%s) returns %ld\n", |
| dentry->d_parent->d_name.name, dentry->d_name.name, |
| res); |
| return res; |
| } |
| |
| loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin) |
| { |
| mutex_lock(&filp->f_path.dentry->d_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; |
| ((struct nfs_open_context *)filp->private_data)->dir_cookie = 0; |
| } |
| out: |
| mutex_unlock(&filp->f_path.dentry->d_inode->i_mutex); |
| return offset; |
| } |
| |
| /* |
| * All directory operations under NFS are synchronous, so fsync() |
| * is a dummy operation. |
| */ |
| int nfs_fsync_dir(struct file *filp, struct dentry *dentry, int datasync) |
| { |
| dfprintk(VFS, "NFS: fsync_dir(%s/%s) datasync %d\n", |
| dentry->d_parent->d_name.name, dentry->d_name.name, |
| datasync); |
| |
| return 0; |
| } |
| |
| /* |
| * 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_I(dir)->cache_validity & NFS_INO_INVALID_ATTR) != 0 |
| || nfs_attribute_timeout(dir)) |
| return 0; |
| return nfs_verify_change_attribute(dir, (unsigned long)dentry->d_fsdata); |
| } |
| |
| static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf) |
| { |
| dentry->d_fsdata = (void *)verf; |
| } |
| |
| static void nfs_refresh_verifier(struct dentry * dentry, unsigned long verf) |
| { |
| if (time_after(verf, (unsigned long)dentry->d_fsdata)) |
| nfs_set_verifier(dentry, verf); |
| } |
| |
| /* |
| * Whenever an NFS operation succeeds, we know that the dentry |
| * is valid, so we update the revalidation timestamp. |
| */ |
| static inline void nfs_renew_times(struct dentry * dentry) |
| { |
| dentry->d_time = jiffies; |
| } |
| |
| /* |
| * 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; |
| } |
| |
| /* |
| * 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 (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 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; |
| 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; |
| unsigned long verifier; |
| |
| parent = dget_parent(dentry); |
| lock_kernel(); |
| 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", |
| __FUNCTION__, dentry->d_parent->d_name.name, |
| dentry->d_name.name); |
| goto out_bad; |
| } |
| |
| /* Revalidate parent directory attribute cache */ |
| if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0) |
| goto out_zap_parent; |
| |
| /* Force a full look up iff the parent directory has changed */ |
| if (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; |
| |
| verifier = nfs_save_change_attribute(dir); |
| 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; |
| |
| nfs_renew_times(dentry); |
| nfs_refresh_verifier(dentry, verifier); |
| out_valid: |
| unlock_kernel(); |
| dput(parent); |
| dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n", |
| __FUNCTION__, dentry->d_parent->d_name.name, |
| dentry->d_name.name); |
| return 1; |
| out_zap_parent: |
| nfs_zap_caches(dir); |
| out_bad: |
| NFS_CACHEINV(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); |
| unlock_kernel(); |
| dput(parent); |
| dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n", |
| __FUNCTION__, 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); |
| |
| 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; |
| |
| } |
| |
| /* |
| * 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) |
| { |
| nfs_inode_return_delegation(inode); |
| if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { |
| lock_kernel(); |
| drop_nlink(inode); |
| nfs_complete_unlink(dentry); |
| unlock_kernel(); |
| } |
| /* When creating a negative dentry, we want to renew d_time */ |
| nfs_renew_times(dentry); |
| iput(inode); |
| } |
| |
| struct dentry_operations nfs_dentry_operations = { |
| .d_revalidate = nfs_lookup_revalidate, |
| .d_delete = nfs_dentry_delete, |
| .d_iput = nfs_dentry_iput, |
| }; |
| |
| /* |
| * Use intent information to check whether or not we're going to do |
| * an O_EXCL create using this path component. |
| */ |
| static inline |
| int nfs_is_exclusive_create(struct inode *dir, struct nameidata *nd) |
| { |
| if (NFS_PROTO(dir)->version == 2) |
| return 0; |
| if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_CREATE) == 0) |
| return 0; |
| return (nd->intent.open.flags & O_EXCL) != 0; |
| } |
| |
| static inline int nfs_reval_fsid(struct vfsmount *mnt, struct inode *dir, |
| struct nfs_fh *fh, struct nfs_fattr *fattr) |
| { |
| struct nfs_server *server = NFS_SERVER(dir); |
| |
| if (!nfs_fsid_equal(&server->fsid, &fattr->fsid)) |
| /* Revalidate fsid on root dir */ |
| return __nfs_revalidate_inode(server, mnt->mnt_root->d_inode); |
| return 0; |
| } |
| |
| static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) |
| { |
| struct dentry *res; |
| 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; |
| |
| lock_kernel(); |
| |
| /* |
| * 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_unlock; |
| } |
| |
| 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_unlock; |
| } |
| error = nfs_reval_fsid(nd->mnt, dir, &fhandle, &fattr); |
| if (error < 0) { |
| res = ERR_PTR(error); |
| goto out_unlock; |
| } |
| inode = nfs_fhget(dentry->d_sb, &fhandle, &fattr); |
| res = (struct dentry *)inode; |
| if (IS_ERR(res)) |
| goto out_unlock; |
| |
| no_entry: |
| res = d_materialise_unique(dentry, inode); |
| if (res != NULL) { |
| struct dentry *parent; |
| if (IS_ERR(res)) |
| goto out_unlock; |
| /* Was a directory renamed! */ |
| parent = dget_parent(res); |
| if (!IS_ROOT(parent)) |
| nfs_mark_for_revalidate(parent->d_inode); |
| dput(parent); |
| dentry = res; |
| } |
| nfs_renew_times(dentry); |
| nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
| out_unlock: |
| unlock_kernel(); |
| out: |
| return res; |
| } |
| |
| #ifdef CONFIG_NFS_V4 |
| static int nfs_open_revalidate(struct dentry *, struct nameidata *); |
| |
| 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 inode *dir, 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 (IS_RDONLY(dir) && (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(dir, 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 */ |
| if (nd->intent.open.flags & O_EXCL) { |
| d_add(dentry, NULL); |
| goto out; |
| } |
| |
| /* Open the file on the server */ |
| lock_kernel(); |
| /* Revalidate parent directory attribute cache */ |
| error = nfs_revalidate_inode(NFS_SERVER(dir), dir); |
| if (error < 0) { |
| res = ERR_PTR(error); |
| unlock_kernel(); |
| goto out; |
| } |
| |
| if (nd->intent.open.flags & O_CREAT) { |
| nfs_begin_data_update(dir); |
| res = nfs4_atomic_open(dir, dentry, nd); |
| nfs_end_data_update(dir); |
| } else |
| res = nfs4_atomic_open(dir, dentry, nd); |
| unlock_kernel(); |
| 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 -EISDIR: |
| case -ENOTDIR: |
| goto no_open; |
| case -ELOOP: |
| if (!(nd->intent.open.flags & O_NOFOLLOW)) |
| goto no_open; |
| /* case -EINVAL: */ |
| default: |
| goto out; |
| } |
| } else if (res != NULL) |
| dentry = res; |
| nfs_renew_times(dentry); |
| nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
| 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; |
| unsigned long verifier; |
| int openflags, ret = 0; |
| |
| parent = dget_parent(dentry); |
| dir = parent->d_inode; |
| if (!is_atomic_open(dir, nd)) |
| goto no_open; |
| /* We can't create new files in nfs_open_revalidate(), so we |
| * optimize away revalidation of negative dentries. |
| */ |
| if (inode == NULL) |
| goto out; |
| /* NFS only supports OPEN on regular files */ |
| if (!S_ISREG(inode->i_mode)) |
| goto no_open; |
| 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; |
| /* 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. |
| */ |
| lock_kernel(); |
| verifier = nfs_save_change_attribute(dir); |
| ret = nfs4_open_revalidate(dir, dentry, openflags, nd); |
| if (!ret) |
| nfs_refresh_verifier(dentry, verifier); |
| unlock_kernel(); |
| out: |
| dput(parent); |
| if (!ret) |
| d_drop(dentry); |
| return ret; |
| no_open: |
| dput(parent); |
| if (inode != NULL && nfs_have_delegation(inode, FMODE_READ)) |
| return 1; |
| 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; |
| |
| 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); |
| } |
| 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; |
| /* 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; |
| } |
| |
| nfs_renew_times(dentry); |
| nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
| return dentry; |
| out_renew: |
| nfs_renew_times(dentry); |
| nfs_refresh_verifier(dentry, nfs_save_change_attribute(dir)); |
| return dentry; |
| } |
| |
| /* |
| * Code common to create, mkdir, and mknod. |
| */ |
| int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle, |
| struct nfs_fattr *fattr) |
| { |
| struct inode *inode; |
| int error = -EACCES; |
| |
| /* We may have been initialized further down */ |
| if (dentry->d_inode) |
| return 0; |
| if (fhandle->size == 0) { |
| struct inode *dir = dentry->d_parent->d_inode; |
| error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr); |
| if (error) |
| return error; |
| } |
| 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) |
| return error; |
| } |
| inode = nfs_fhget(dentry->d_sb, fhandle, fattr); |
| error = PTR_ERR(inode); |
| if (IS_ERR(inode)) |
| return error; |
| d_instantiate(dentry, inode); |
| if (d_unhashed(dentry)) |
| d_rehash(dentry); |
| return 0; |
| } |
| |
| /* |
| * 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 && (nd->flags & LOOKUP_CREATE)) |
| open_flags = nd->intent.open.flags; |
| |
| lock_kernel(); |
| nfs_begin_data_update(dir); |
| error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, nd); |
| nfs_end_data_update(dir); |
| if (error != 0) |
| goto out_err; |
| nfs_renew_times(dentry); |
| nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
| unlock_kernel(); |
| return 0; |
| out_err: |
| unlock_kernel(); |
| 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; |
| |
| lock_kernel(); |
| nfs_begin_data_update(dir); |
| status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev); |
| nfs_end_data_update(dir); |
| if (status != 0) |
| goto out_err; |
| nfs_renew_times(dentry); |
| nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
| unlock_kernel(); |
| return 0; |
| out_err: |
| unlock_kernel(); |
| 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; |
| |
| lock_kernel(); |
| nfs_begin_data_update(dir); |
| error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr); |
| nfs_end_data_update(dir); |
| if (error != 0) |
| goto out_err; |
| nfs_renew_times(dentry); |
| nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
| unlock_kernel(); |
| return 0; |
| out_err: |
| d_drop(dentry); |
| unlock_kernel(); |
| return error; |
| } |
| |
| 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); |
| |
| lock_kernel(); |
| nfs_begin_data_update(dir); |
| 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); |
| nfs_end_data_update(dir); |
| unlock_kernel(); |
| |
| return error; |
| } |
| |
| static int nfs_sillyrename(struct inode *dir, struct dentry *dentry) |
| { |
| static unsigned int sillycounter; |
| const int i_inosize = sizeof(dir->i_ino)*2; |
| const int countersize = sizeof(sillycounter)*2; |
| const int slen = sizeof(".nfs") + i_inosize + 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); |
| |
| #ifdef NFS_PARANOIA |
| if (!dentry->d_inode) |
| printk("NFS: silly-renaming %s/%s, negative dentry??\n", |
| dentry->d_parent->d_name.name, dentry->d_name.name); |
| #endif |
| /* |
| * 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", |
| i_inosize, i_inosize, dentry->d_inode->i_ino); |
| |
| /* 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); |
| nfs_begin_data_update(dir); |
| if (dentry->d_inode) { |
| nfs_begin_data_update(dentry->d_inode); |
| error = NFS_PROTO(dir)->rename(dir, &dentry->d_name, |
| dir, &qsilly); |
| nfs_mark_for_revalidate(dentry->d_inode); |
| nfs_end_data_update(dentry->d_inode); |
| } else |
| error = NFS_PROTO(dir)->rename(dir, &dentry->d_name, |
| dir, &qsilly); |
| nfs_end_data_update(dir); |
| if (!error) { |
| nfs_renew_times(dentry); |
| nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
| d_move(dentry, sdentry); |
| error = nfs_async_unlink(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; |
| } |
| |
| nfs_begin_data_update(dir); |
| if (inode != NULL) { |
| nfs_inode_return_delegation(inode); |
| nfs_begin_data_update(inode); |
| error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); |
| /* The VFS may want to delete this inode */ |
| if (error == 0) |
| drop_nlink(inode); |
| nfs_mark_for_revalidate(inode); |
| nfs_end_data_update(inode); |
| } else |
| error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); |
| nfs_end_data_update(dir); |
| 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); |
| |
| lock_kernel(); |
| 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); |
| unlock_kernel(); |
| 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) { |
| nfs_renew_times(dentry); |
| nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
| } else if (need_rehash) |
| d_rehash(dentry); |
| unlock_kernel(); |
| 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; |
| |
| lock_kernel(); |
| |
| page = alloc_page(GFP_KERNEL); |
| if (!page) { |
| unlock_kernel(); |
| 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); |
| |
| nfs_begin_data_update(dir); |
| error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr); |
| nfs_end_data_update(dir); |
| 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); |
| unlock_kernel(); |
| 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(&lru_pvec); |
| SetPageUptodate(page); |
| unlock_page(page); |
| } else |
| __free_page(page); |
| |
| unlock_kernel(); |
| 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); |
| |
| lock_kernel(); |
| nfs_begin_data_update(dir); |
| nfs_begin_data_update(inode); |
| error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name); |
| if (error == 0) { |
| atomic_inc(&inode->i_count); |
| d_instantiate(dentry, inode); |
| } |
| nfs_end_data_update(inode); |
| nfs_end_data_update(dir); |
| unlock_kernel(); |
| 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; |
| |
| /* |
| * To prevent any new references to the target during the rename, |
| * we unhash the dentry and free the inode in advance. |
| */ |
| lock_kernel(); |
| if (!d_unhashed(new_dentry)) { |
| d_drop(new_dentry); |
| rehash = new_dentry; |
| } |
| |
| 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)); |
| |
| /* |
| * First check whether the target is busy ... we can't |
| * safely do _any_ rename if the target is in use. |
| * |
| * For files, 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) |
| goto go_ahead; |
| if (S_ISDIR(new_inode->i_mode)) { |
| error = -EISDIR; |
| if (!S_ISDIR(old_inode->i_mode)) |
| goto out; |
| } else 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) { |
| new_dentry = rehash = dentry; |
| new_inode = NULL; |
| /* instantiate the replacement target */ |
| d_instantiate(new_dentry, NULL); |
| } else if (atomic_read(&new_dentry->d_count) > 1) { |
| /* dentry still busy? */ |
| #ifdef NFS_PARANOIA |
| printk("nfs_rename: target %s/%s busy, d_count=%d\n", |
| new_dentry->d_parent->d_name.name, |
| new_dentry->d_name.name, |
| atomic_read(&new_dentry->d_count)); |
| #endif |
| goto out; |
| } |
| } else |
| drop_nlink(new_inode); |
| |
| go_ahead: |
| /* |
| * ... 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); |
| d_delete(new_dentry); |
| } |
| |
| nfs_begin_data_update(old_dir); |
| nfs_begin_data_update(new_dir); |
| nfs_begin_data_update(old_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); |
| nfs_end_data_update(old_inode); |
| nfs_end_data_update(new_dir); |
| nfs_end_data_update(old_dir); |
| out: |
| if (rehash) |
| d_rehash(rehash); |
| if (!error) { |
| d_move(old_dentry, new_dentry); |
| nfs_renew_times(new_dentry); |
| nfs_refresh_verifier(new_dentry, nfs_save_change_attribute(new_dir)); |
| } |
| |
| /* new dentry created? */ |
| if (dentry) |
| dput(dentry); |
| unlock_kernel(); |
| 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; |
| |
| spin_lock(&nfs_access_lru_lock); |
| restart: |
| list_for_each_entry(nfsi, &nfs_access_lru_list, access_cache_inode_lru) { |
| struct inode *inode; |
| |
| if (nr_to_scan-- == 0) |
| break; |
| inode = igrab(&nfsi->vfs_inode); |
| if (inode == NULL) |
| 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); |
| iput(inode); |
| 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_FLAGS(inode))) { |
| 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; |
| } |
| |
| 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 (time_after(jiffies, cache->jiffies + NFS_ATTRTIMEO(inode))) |
| 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); |
| } |
| |
| 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_FLAGS(inode))) { |
| 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) |
| return status; |
| nfs_access_add_cache(inode, &cache); |
| out: |
| if ((cache.mask & mask) == mask) |
| return 0; |
| return -EACCES; |
| } |
| |
| int nfs_permission(struct inode *inode, int mask, struct nameidata *nd) |
| { |
| struct rpc_cred *cred; |
| int res = 0; |
| |
| nfs_inc_stats(inode, NFSIOS_VFSACCESS); |
| |
| if (mask == 0) |
| goto out; |
| /* Is this sys_access() ? */ |
| if (nd != NULL && (nd->flags & LOOKUP_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) |
| && nd != NULL |
| && (nd->flags & LOOKUP_OPEN)) |
| 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: |
| lock_kernel(); |
| |
| if (!NFS_PROTO(inode)->access) |
| goto out_notsup; |
| |
| cred = rpcauth_lookupcred(NFS_CLIENT(inode)->cl_auth, 0); |
| if (!IS_ERR(cred)) { |
| res = nfs_do_access(inode, cred, mask); |
| put_rpccred(cred); |
| } else |
| res = PTR_ERR(cred); |
| unlock_kernel(); |
| out: |
| 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); |
| unlock_kernel(); |
| goto out; |
| } |
| |
| /* |
| * Local variables: |
| * version-control: t |
| * kept-new-versions: 5 |
| * End: |
| */ |