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 52 p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n", 53 dentry, dentry); 54 hlist_for_each_safe(p, n, (struct hlist_head *)&dentry->d_fsdata) 55 p9_fid_put(hlist_entry(p, struct p9_fid, dlist)); 56 dentry->d_fsdata = NULL; 57 } 58 59 static int v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags) 60 { 61 struct p9_fid *fid; 62 struct inode *inode; 63 struct v9fs_inode *v9inode; 64 65 if (flags & LOOKUP_RCU) 66 return -ECHILD; 67 68 inode = d_inode(dentry); 69 if (!inode) 70 goto out_valid; 71 72 v9inode = V9FS_I(inode); 73 if (v9inode->cache_validity & V9FS_INO_INVALID_ATTR) { 74 int retval; 75 struct v9fs_session_info *v9ses; 76 77 fid = v9fs_fid_lookup(dentry); 78 if (IS_ERR(fid)) 79 return PTR_ERR(fid); 80 81 v9ses = v9fs_inode2v9ses(inode); 82 if (v9fs_proto_dotl(v9ses)) 83 retval = v9fs_refresh_inode_dotl(fid, inode); 84 else 85 retval = v9fs_refresh_inode(fid, inode); 86 p9_fid_put(fid); 87 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 }; 108