| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2 | /* |
| 3 | * linux/fs/9p/vfs_dentry.c |
| 4 | * |
| 5 | * This file contians vfs dentry ops for the 9P2000 protocol. |
| 6 | * |
| 7 | * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> |
| 8 | * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> |
| 9 | */ |
| 10 | |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/errno.h> |
| 13 | #include <linux/fs.h> |
| 14 | #include <linux/file.h> |
| 15 | #include <linux/pagemap.h> |
| 16 | #include <linux/stat.h> |
| 17 | #include <linux/string.h> |
| 18 | #include <linux/inet.h> |
| 19 | #include <linux/namei.h> |
| 20 | #include <linux/idr.h> |
| 21 | #include <linux/sched.h> |
| 22 | #include <linux/slab.h> |
| 23 | #include <net/9p/9p.h> |
| 24 | #include <net/9p/client.h> |
| 25 | |
| 26 | #include "v9fs.h" |
| 27 | #include "v9fs_vfs.h" |
| 28 | #include "fid.h" |
| 29 | |
| 30 | /** |
| 31 | * v9fs_cached_dentry_delete - called when dentry refcount equals 0 |
| 32 | * @dentry: dentry in question |
| 33 | * |
| 34 | */ |
| 35 | static int v9fs_cached_dentry_delete(const struct dentry *dentry) |
| 36 | { |
| 37 | p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n", |
| 38 | dentry, dentry); |
| 39 | |
| 40 | /* Don't cache negative dentries */ |
| 41 | if (d_really_is_negative(dentry)) |
| 42 | return 1; |
| 43 | return 0; |
| 44 | } |
| 45 | |
| 46 | /** |
| 47 | * v9fs_dentry_release - called when dentry is going to be freed |
| 48 | * @dentry: dentry that is being release |
| 49 | * |
| 50 | */ |
| 51 | |
| 52 | static void v9fs_dentry_release(struct dentry *dentry) |
| 53 | { |
| 54 | struct hlist_node *p, *n; |
| 55 | p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n", |
| 56 | dentry, dentry); |
| 57 | hlist_for_each_safe(p, n, (struct hlist_head *)&dentry->d_fsdata) |
| 58 | p9_client_clunk(hlist_entry(p, struct p9_fid, dlist)); |
| 59 | dentry->d_fsdata = NULL; |
| 60 | } |
| 61 | |
| 62 | static int v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags) |
| 63 | { |
| 64 | struct p9_fid *fid; |
| 65 | struct inode *inode; |
| 66 | struct v9fs_inode *v9inode; |
| 67 | |
| 68 | if (flags & LOOKUP_RCU) |
| 69 | return -ECHILD; |
| 70 | |
| 71 | inode = d_inode(dentry); |
| 72 | if (!inode) |
| 73 | goto out_valid; |
| 74 | |
| 75 | v9inode = V9FS_I(inode); |
| 76 | if (v9inode->cache_validity & V9FS_INO_INVALID_ATTR) { |
| 77 | int retval; |
| 78 | struct v9fs_session_info *v9ses; |
| 79 | fid = v9fs_fid_lookup(dentry); |
| 80 | if (IS_ERR(fid)) |
| 81 | return PTR_ERR(fid); |
| 82 | |
| 83 | v9ses = v9fs_inode2v9ses(inode); |
| 84 | if (v9fs_proto_dotl(v9ses)) |
| 85 | retval = v9fs_refresh_inode_dotl(fid, inode); |
| 86 | else |
| 87 | retval = v9fs_refresh_inode(fid, inode); |
| 88 | if (retval == -ENOENT) |
| 89 | return 0; |
| 90 | if (retval < 0) |
| 91 | return retval; |
| 92 | } |
| 93 | out_valid: |
| 94 | return 1; |
| 95 | } |
| 96 | |
| 97 | const struct dentry_operations v9fs_cached_dentry_operations = { |
| 98 | .d_revalidate = v9fs_lookup_revalidate, |
| 99 | .d_weak_revalidate = v9fs_lookup_revalidate, |
| 100 | .d_delete = v9fs_cached_dentry_delete, |
| 101 | .d_release = v9fs_dentry_release, |
| 102 | }; |
| 103 | |
| 104 | const struct dentry_operations v9fs_dentry_operations = { |
| 105 | .d_delete = always_delete_dentry, |
| 106 | .d_release = v9fs_dentry_release, |
| 107 | }; |