xref: /linux/fs/notify/fdinfo.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 #include <linux/file.h>
2 #include <linux/fs.h>
3 #include <linux/fsnotify_backend.h>
4 #include <linux/idr.h>
5 #include <linux/init.h>
6 #include <linux/inotify.h>
7 #include <linux/fanotify.h>
8 #include <linux/kernel.h>
9 #include <linux/namei.h>
10 #include <linux/sched.h>
11 #include <linux/types.h>
12 #include <linux/seq_file.h>
13 #include <linux/proc_fs.h>
14 #include <linux/exportfs.h>
15 
16 #include "inotify/inotify.h"
17 #include "../fs/mount.h"
18 
19 #if defined(CONFIG_PROC_FS)
20 
21 #if defined(CONFIG_INOTIFY_USER) || defined(CONFIG_FANOTIFY)
22 
23 static int show_fdinfo(struct seq_file *m, struct file *f,
24 		       int (*show)(struct seq_file *m, struct fsnotify_mark *mark))
25 {
26 	struct fsnotify_group *group = f->private_data;
27 	struct fsnotify_mark *mark;
28 	int ret = 0;
29 
30 	mutex_lock(&group->mark_mutex);
31 	list_for_each_entry(mark, &group->marks_list, g_list) {
32 		ret = show(m, mark);
33 		if (ret)
34 			break;
35 	}
36 	mutex_unlock(&group->mark_mutex);
37 	return ret;
38 }
39 
40 #if defined(CONFIG_EXPORTFS)
41 static int show_mark_fhandle(struct seq_file *m, struct inode *inode)
42 {
43 	struct {
44 		struct file_handle handle;
45 		u8 pad[64];
46 	} f;
47 	int size, ret, i;
48 
49 	f.handle.handle_bytes = sizeof(f.pad);
50 	size = f.handle.handle_bytes >> 2;
51 
52 	ret = exportfs_encode_inode_fh(inode, (struct fid *)f.handle.f_handle, &size, 0);
53 	if ((ret == 255) || (ret == -ENOSPC)) {
54 		WARN_ONCE(1, "Can't encode file handler for inotify: %d\n", ret);
55 		return 0;
56 	}
57 
58 	f.handle.handle_type = ret;
59 	f.handle.handle_bytes = size * sizeof(u32);
60 
61 	ret = seq_printf(m, "fhandle-bytes:%x fhandle-type:%x f_handle:",
62 			 f.handle.handle_bytes, f.handle.handle_type);
63 
64 	for (i = 0; i < f.handle.handle_bytes; i++)
65 		ret |= seq_printf(m, "%02x", (int)f.handle.f_handle[i]);
66 
67 	return ret;
68 }
69 #else
70 static int show_mark_fhandle(struct seq_file *m, struct inode *inode)
71 {
72 	return 0;
73 }
74 #endif
75 
76 #ifdef CONFIG_INOTIFY_USER
77 
78 static int inotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
79 {
80 	struct inotify_inode_mark *inode_mark;
81 	struct inode *inode;
82 	int ret = 0;
83 
84 	if (!(mark->flags & (FSNOTIFY_MARK_FLAG_ALIVE | FSNOTIFY_MARK_FLAG_INODE)))
85 		return 0;
86 
87 	inode_mark = container_of(mark, struct inotify_inode_mark, fsn_mark);
88 	inode = igrab(mark->i.inode);
89 	if (inode) {
90 		ret = seq_printf(m, "inotify wd:%x ino:%lx sdev:%x "
91 				 "mask:%x ignored_mask:%x ",
92 				 inode_mark->wd, inode->i_ino,
93 				 inode->i_sb->s_dev,
94 				 mark->mask, mark->ignored_mask);
95 		ret |= show_mark_fhandle(m, inode);
96 		ret |= seq_putc(m, '\n');
97 		iput(inode);
98 	}
99 
100 	return ret;
101 }
102 
103 int inotify_show_fdinfo(struct seq_file *m, struct file *f)
104 {
105 	return show_fdinfo(m, f, inotify_fdinfo);
106 }
107 
108 #endif /* CONFIG_INOTIFY_USER */
109 
110 #ifdef CONFIG_FANOTIFY
111 
112 static int fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
113 {
114 	unsigned int mflags = 0;
115 	struct inode *inode;
116 	int ret = 0;
117 
118 	if (!(mark->flags & FSNOTIFY_MARK_FLAG_ALIVE))
119 		return 0;
120 
121 	if (mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)
122 		mflags |= FAN_MARK_IGNORED_SURV_MODIFY;
123 
124 	if (mark->flags & FSNOTIFY_MARK_FLAG_INODE) {
125 		inode = igrab(mark->i.inode);
126 		if (!inode)
127 			goto out;
128 		ret = seq_printf(m, "fanotify ino:%lx sdev:%x "
129 				 "mflags:%x mask:%x ignored_mask:%x ",
130 				 inode->i_ino, inode->i_sb->s_dev,
131 				 mflags, mark->mask, mark->ignored_mask);
132 		ret |= show_mark_fhandle(m, inode);
133 		ret |= seq_putc(m, '\n');
134 		iput(inode);
135 	} else if (mark->flags & FSNOTIFY_MARK_FLAG_VFSMOUNT) {
136 		struct mount *mnt = real_mount(mark->m.mnt);
137 
138 		ret = seq_printf(m, "fanotify mnt_id:%x mflags:%x mask:%x "
139 				 "ignored_mask:%x\n", mnt->mnt_id, mflags,
140 				 mark->mask, mark->ignored_mask);
141 	}
142 out:
143 	return ret;
144 }
145 
146 int fanotify_show_fdinfo(struct seq_file *m, struct file *f)
147 {
148 	struct fsnotify_group *group = f->private_data;
149 	unsigned int flags = 0;
150 
151 	switch (group->priority) {
152 	case FS_PRIO_0:
153 		flags |= FAN_CLASS_NOTIF;
154 		break;
155 	case FS_PRIO_1:
156 		flags |= FAN_CLASS_CONTENT;
157 		break;
158 	case FS_PRIO_2:
159 		flags |= FAN_CLASS_PRE_CONTENT;
160 		break;
161 	}
162 
163 	if (group->max_events == UINT_MAX)
164 		flags |= FAN_UNLIMITED_QUEUE;
165 
166 	if (group->fanotify_data.max_marks == UINT_MAX)
167 		flags |= FAN_UNLIMITED_MARKS;
168 
169 	seq_printf(m, "fanotify flags:%x event-flags:%x\n",
170 		   flags, group->fanotify_data.f_flags);
171 
172 	return show_fdinfo(m, f, fanotify_fdinfo);
173 }
174 
175 #endif /* CONFIG_FANOTIFY */
176 
177 #endif /* CONFIG_INOTIFY_USER || CONFIG_FANOTIFY */
178 
179 #endif /* CONFIG_PROC_FS */
180