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/namei.h> 17 #include <linux/sched.h> 18 #include <linux/slab.h> 19 #include <net/9p/9p.h> 20 #include <net/9p/client.h> 21 22 #include "v9fs.h" 23 #include "v9fs_vfs.h" 24 #include "fid.h" 25 26 /** 27 * v9fs_cached_dentry_delete - called when dentry refcount equals 0 28 * @dentry: dentry in question 29 * 30 */ 31 static int v9fs_cached_dentry_delete(const struct dentry *dentry) 32 { 33 p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n", 34 dentry, dentry); 35 36 /* Don't cache negative dentries */ 37 if (d_really_is_negative(dentry)) 38 return 1; 39 return 0; 40 } 41 42 /** 43 * v9fs_dentry_release - called when dentry is going to be freed 44 * @dentry: dentry that is being release 45 * 46 */ 47 48 static void v9fs_dentry_release(struct dentry *dentry) 49 { 50 struct hlist_node *p, *n; 51 struct hlist_head head; 52 53 p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n", 54 dentry, dentry); 55 56 spin_lock(&dentry->d_lock); 57 hlist_move_list((struct hlist_head *)&dentry->d_fsdata, &head); 58 spin_unlock(&dentry->d_lock); 59 60 hlist_for_each_safe(p, n, &head) 61 p9_fid_put(hlist_entry(p, struct p9_fid, dlist)); 62 } 63 64 static int v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags) 65 { 66 struct p9_fid *fid; 67 struct inode *inode; 68 struct v9fs_inode *v9inode; 69 70 if (flags & LOOKUP_RCU) 71 return -ECHILD; 72 73 inode = d_inode(dentry); 74 if (!inode) 75 goto out_valid; 76 77 v9inode = V9FS_I(inode); 78 if (v9inode->cache_validity & V9FS_INO_INVALID_ATTR) { 79 int retval; 80 struct v9fs_session_info *v9ses; 81 82 fid = v9fs_fid_lookup(dentry); 83 if (IS_ERR(fid)) 84 return PTR_ERR(fid); 85 86 v9ses = v9fs_inode2v9ses(inode); 87 if (v9fs_proto_dotl(v9ses)) 88 retval = v9fs_refresh_inode_dotl(fid, inode); 89 else 90 retval = v9fs_refresh_inode(fid, inode); 91 p9_fid_put(fid); 92 93 if (retval == -ENOENT) 94 return 0; 95 if (retval < 0) 96 return retval; 97 } 98 out_valid: 99 return 1; 100 } 101 102 const struct dentry_operations v9fs_cached_dentry_operations = { 103 .d_revalidate = v9fs_lookup_revalidate, 104 .d_weak_revalidate = v9fs_lookup_revalidate, 105 .d_delete = v9fs_cached_dentry_delete, 106 .d_release = v9fs_dentry_release, 107 }; 108 109 const struct dentry_operations v9fs_dentry_operations = { 110 .d_delete = always_delete_dentry, 111 .d_release = v9fs_dentry_release, 112 }; 113