Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/nfs/symlink.c |
| 3 | * |
| 4 | * Copyright (C) 1992 Rick Sladkey |
| 5 | * |
| 6 | * Optimization changes Copyright (C) 1994 Florian La Roche |
| 7 | * |
| 8 | * Jun 7 1999, cache symlink lookups in the page cache. -DaveM |
| 9 | * |
| 10 | * nfs symlink handling code |
| 11 | */ |
| 12 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/time.h> |
| 14 | #include <linux/errno.h> |
| 15 | #include <linux/sunrpc/clnt.h> |
| 16 | #include <linux/nfs.h> |
| 17 | #include <linux/nfs2.h> |
| 18 | #include <linux/nfs_fs.h> |
| 19 | #include <linux/pagemap.h> |
| 20 | #include <linux/stat.h> |
| 21 | #include <linux/mm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <linux/string.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | |
| 24 | /* Symlink caching in the page cache is even more simplistic |
| 25 | * and straight-forward than readdir caching. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | */ |
| 27 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | static int nfs_symlink_filler(struct inode *inode, struct page *page) |
| 29 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | int error; |
| 31 | |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 32 | error = NFS_PROTO(inode)->readlink(inode, page, 0, PAGE_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | if (error < 0) |
| 34 | goto error; |
| 35 | SetPageUptodate(page); |
| 36 | unlock_page(page); |
| 37 | return 0; |
| 38 | |
| 39 | error: |
| 40 | SetPageError(page); |
| 41 | unlock_page(page); |
| 42 | return -EIO; |
| 43 | } |
| 44 | |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 45 | static const char *nfs_get_link(struct dentry *dentry, |
| 46 | struct inode *inode, void **cookie) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | struct page *page; |
Trond Myklebust | 717d44e | 2007-01-24 11:54:55 -0800 | [diff] [blame] | 49 | void *err; |
| 50 | |
Al Viro | 0d0def4 | 2015-11-17 21:14:24 -0500 | [diff] [blame] | 51 | if (!dentry) { |
| 52 | err = ERR_PTR(nfs_revalidate_mapping_rcu(inode)); |
| 53 | if (err) |
| 54 | return err; |
| 55 | page = find_get_page(inode->i_mapping, 0); |
| 56 | if (!page) |
| 57 | return ERR_PTR(-ECHILD); |
| 58 | if (!PageUptodate(page)) { |
| 59 | put_page(page); |
| 60 | return ERR_PTR(-ECHILD); |
| 61 | } |
| 62 | } else { |
| 63 | err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping)); |
| 64 | if (err) |
| 65 | return err; |
| 66 | page = read_cache_page(&inode->i_data, 0, |
| 67 | (filler_t *)nfs_symlink_filler, inode); |
| 68 | if (IS_ERR(page)) |
| 69 | return ERR_CAST(page); |
| 70 | } |
Al Viro | 680baac | 2015-05-02 13:32:22 -0400 | [diff] [blame] | 71 | *cookie = page; |
Al Viro | 21fc61c | 2015-11-17 01:07:57 -0500 | [diff] [blame] | 72 | return page_address(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | } |
| 74 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | /* |
| 76 | * symlinks can't do much... |
| 77 | */ |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 78 | const struct inode_operations nfs_symlink_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | .readlink = generic_readlink, |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 80 | .get_link = nfs_get_link, |
Alexey Dobriyan | 9bf2aa1 | 2006-06-25 02:41:28 -0700 | [diff] [blame] | 81 | .put_link = page_put_link, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | .getattr = nfs_getattr, |
| 83 | .setattr = nfs_setattr, |
| 84 | }; |