xref: /openbmc/linux/fs/notify/fdinfo.c (revision aeb64ff3)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/file.h>
3 #include <linux/fs.h>
4 #include <linux/fsnotify_backend.h>
5 #include <linux/idr.h>
6 #include <linux/init.h>
7 #include <linux/inotify.h>
8 #include <linux/fanotify.h>
9 #include <linux/kernel.h>
10 #include <linux/namei.h>
11 #include <linux/sched.h>
12 #include <linux/types.h>
13 #include <linux/seq_file.h>
14 #include <linux/proc_fs.h>
15 #include <linux/exportfs.h>
16 
17 #include "inotify/inotify.h"
18 #include "fdinfo.h"
19 #include "fsnotify.h"
20 
21 #if defined(CONFIG_PROC_FS)
22 
23 #if defined(CONFIG_INOTIFY_USER) || defined(CONFIG_FANOTIFY)
24 
25 static void show_fdinfo(struct seq_file *m, struct file *f,
26 			void (*show)(struct seq_file *m,
27 				     struct fsnotify_mark *mark))
28 {
29 	struct fsnotify_group *group = f->private_data;
30 	struct fsnotify_mark *mark;
31 
32 	mutex_lock(&group->mark_mutex);
33 	list_for_each_entry(mark, &group->marks_list, g_list) {
34 		show(m, mark);
35 		if (seq_has_overflowed(m))
36 			break;
37 	}
38 	mutex_unlock(&group->mark_mutex);
39 }
40 
41 #if defined(CONFIG_EXPORTFS)
42 static void show_mark_fhandle(struct seq_file *m, struct inode *inode)
43 {
44 	struct {
45 		struct file_handle handle;
46 		u8 pad[MAX_HANDLE_SZ];
47 	} f;
48 	int size, ret, i;
49 
50 	f.handle.handle_bytes = sizeof(f.pad);
51 	size = f.handle.handle_bytes >> 2;
52 
53 	ret = exportfs_encode_inode_fh(inode, (struct fid *)f.handle.f_handle, &size, NULL);
54 	if ((ret == FILEID_INVALID) || (ret < 0)) {
55 		WARN_ONCE(1, "Can't encode file handler for inotify: %d\n", ret);
56 		return;
57 	}
58 
59 	f.handle.handle_type = ret;
60 	f.handle.handle_bytes = size * sizeof(u32);
61 
62 	seq_printf(m, "fhandle-bytes:%x fhandle-type:%x f_handle:",
63 		   f.handle.handle_bytes, f.handle.handle_type);
64 
65 	for (i = 0; i < f.handle.handle_bytes; i++)
66 		seq_printf(m, "%02x", (int)f.handle.f_handle[i]);
67 }
68 #else
69 static void show_mark_fhandle(struct seq_file *m, struct inode *inode)
70 {
71 }
72 #endif
73 
74 #ifdef CONFIG_INOTIFY_USER
75 
76 static void inotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
77 {
78 	struct inotify_inode_mark *inode_mark;
79 	struct inode *inode;
80 
81 	if (mark->connector->type != FSNOTIFY_OBJ_TYPE_INODE)
82 		return;
83 
84 	inode_mark = container_of(mark, struct inotify_inode_mark, fsn_mark);
85 	inode = igrab(fsnotify_conn_inode(mark->connector));
86 	if (inode) {
87 		/*
88 		 * IN_ALL_EVENTS represents all of the mask bits
89 		 * that we expose to userspace.  There is at
90 		 * least one bit (FS_EVENT_ON_CHILD) which is
91 		 * used only internally to the kernel.
92 		 */
93 		u32 mask = mark->mask & IN_ALL_EVENTS;
94 		seq_printf(m, "inotify wd:%x ino:%lx sdev:%x mask:%x ignored_mask:%x ",
95 			   inode_mark->wd, inode->i_ino, inode->i_sb->s_dev,
96 			   mask, mark->ignored_mask);
97 		show_mark_fhandle(m, inode);
98 		seq_putc(m, '\n');
99 		iput(inode);
100 	}
101 }
102 
103 void inotify_show_fdinfo(struct seq_file *m, struct file *f)
104 {
105 	show_fdinfo(m, f, inotify_fdinfo);
106 }
107 
108 #endif /* CONFIG_INOTIFY_USER */
109 
110 #ifdef CONFIG_FANOTIFY
111 
112 static void fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
113 {
114 	unsigned int mflags = 0;
115 	struct inode *inode;
116 
117 	if (mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)
118 		mflags |= FAN_MARK_IGNORED_SURV_MODIFY;
119 
120 	if (mark->connector->type == FSNOTIFY_OBJ_TYPE_INODE) {
121 		inode = igrab(fsnotify_conn_inode(mark->connector));
122 		if (!inode)
123 			return;
124 		seq_printf(m, "fanotify ino:%lx sdev:%x mflags:%x mask:%x ignored_mask:%x ",
125 			   inode->i_ino, inode->i_sb->s_dev,
126 			   mflags, mark->mask, mark->ignored_mask);
127 		show_mark_fhandle(m, inode);
128 		seq_putc(m, '\n');
129 		iput(inode);
130 	} else if (mark->connector->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
131 		struct mount *mnt = fsnotify_conn_mount(mark->connector);
132 
133 		seq_printf(m, "fanotify mnt_id:%x mflags:%x mask:%x ignored_mask:%x\n",
134 			   mnt->mnt_id, mflags, mark->mask, mark->ignored_mask);
135 	} else if (mark->connector->type == FSNOTIFY_OBJ_TYPE_SB) {
136 		struct super_block *sb = fsnotify_conn_sb(mark->connector);
137 
138 		seq_printf(m, "fanotify sdev:%x mflags:%x mask:%x ignored_mask:%x\n",
139 			   sb->s_dev, mflags, mark->mask, mark->ignored_mask);
140 	}
141 }
142 
143 void fanotify_show_fdinfo(struct seq_file *m, struct file *f)
144 {
145 	struct fsnotify_group *group = f->private_data;
146 
147 	seq_printf(m, "fanotify flags:%x event-flags:%x\n",
148 		   group->fanotify_data.flags, group->fanotify_data.f_flags);
149 
150 	show_fdinfo(m, f, fanotify_fdinfo);
151 }
152 
153 #endif /* CONFIG_FANOTIFY */
154 
155 #endif /* CONFIG_INOTIFY_USER || CONFIG_FANOTIFY */
156 
157 #endif /* CONFIG_PROC_FS */
158