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 p9_client_clunk(fid); 89 90 if (retval == -ENOENT) 91 return 0; 92 if (retval < 0) 93 return retval; 94 } 95 out_valid: 96 return 1; 97 } 98 99 const struct dentry_operations v9fs_cached_dentry_operations = { 100 .d_revalidate = v9fs_lookup_revalidate, 101 .d_weak_revalidate = v9fs_lookup_revalidate, 102 .d_delete = v9fs_cached_dentry_delete, 103 .d_release = v9fs_dentry_release, 104 }; 105 106 const struct dentry_operations v9fs_dentry_operations = { 107 .d_delete = always_delete_dentry, 108 .d_release = v9fs_dentry_release, 109 }; 110