1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * This file contians vfs dentry ops for the 9P2000 protocol. 4 * 5 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> 6 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> 7 */ 8 9 #include <linux/module.h> 10 #include <linux/errno.h> 11 #include <linux/fs.h> 12 #include <linux/file.h> 13 #include <linux/pagemap.h> 14 #include <linux/stat.h> 15 #include <linux/string.h> 16 #include <linux/inet.h> 17 #include <linux/namei.h> 18 #include <linux/sched.h> 19 #include <linux/slab.h> 20 #include <net/9p/9p.h> 21 #include <net/9p/client.h> 22 23 #include "v9fs.h" 24 #include "v9fs_vfs.h" 25 #include "fid.h" 26 27 /** 28 * v9fs_cached_dentry_delete - called when dentry refcount equals 0 29 * @dentry: dentry in question 30 * 31 */ 32 static int v9fs_cached_dentry_delete(const struct dentry *dentry) 33 { 34 p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n", 35 dentry, dentry); 36 37 /* Don't cache negative dentries */ 38 if (d_really_is_negative(dentry)) 39 return 1; 40 return 0; 41 } 42 43 /** 44 * v9fs_dentry_release - called when dentry is going to be freed 45 * @dentry: dentry that is being release 46 * 47 */ 48 49 static void v9fs_dentry_release(struct dentry *dentry) 50 { 51 struct hlist_node *p, *n; 52 53 p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n", 54 dentry, dentry); 55 hlist_for_each_safe(p, n, (struct hlist_head *)&dentry->d_fsdata) 56 p9_fid_put(hlist_entry(p, struct p9_fid, dlist)); 57 dentry->d_fsdata = NULL; 58 } 59 60 static int v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags) 61 { 62 struct p9_fid *fid; 63 struct inode *inode; 64 struct v9fs_inode *v9inode; 65 66 if (flags & LOOKUP_RCU) 67 return -ECHILD; 68 69 inode = d_inode(dentry); 70 if (!inode) 71 goto out_valid; 72 73 v9inode = V9FS_I(inode); 74 if (v9inode->cache_validity & V9FS_INO_INVALID_ATTR) { 75 int retval; 76 struct v9fs_session_info *v9ses; 77 78 fid = v9fs_fid_lookup(dentry); 79 if (IS_ERR(fid)) 80 return PTR_ERR(fid); 81 82 v9ses = v9fs_inode2v9ses(inode); 83 if (v9fs_proto_dotl(v9ses)) 84 retval = v9fs_refresh_inode_dotl(fid, inode); 85 else 86 retval = v9fs_refresh_inode(fid, inode); 87 p9_fid_put(fid); 88 89 if (retval == -ENOENT) 90 return 0; 91 if (retval < 0) 92 return retval; 93 } 94 out_valid: 95 return 1; 96 } 97 98 const struct dentry_operations v9fs_cached_dentry_operations = { 99 .d_revalidate = v9fs_lookup_revalidate, 100 .d_weak_revalidate = v9fs_lookup_revalidate, 101 .d_delete = v9fs_cached_dentry_delete, 102 .d_release = v9fs_dentry_release, 103 }; 104 105 const struct dentry_operations v9fs_dentry_operations = { 106 .d_delete = always_delete_dentry, 107 .d_release = v9fs_dentry_release, 108 }; 109