xref: /openbmc/linux/fs/notify/fdinfo.c (revision dea54fba)
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 void show_fdinfo(struct seq_file *m, struct file *f,
24 			void (*show)(struct seq_file *m,
25 				     struct fsnotify_mark *mark))
26 {
27 	struct fsnotify_group *group = f->private_data;
28 	struct fsnotify_mark *mark;
29 
30 	mutex_lock(&group->mark_mutex);
31 	list_for_each_entry(mark, &group->marks_list, g_list) {
32 		show(m, mark);
33 		if (seq_has_overflowed(m))
34 			break;
35 	}
36 	mutex_unlock(&group->mark_mutex);
37 }
38 
39 #if defined(CONFIG_EXPORTFS)
40 static void show_mark_fhandle(struct seq_file *m, struct inode *inode)
41 {
42 	struct {
43 		struct file_handle handle;
44 		u8 pad[MAX_HANDLE_SZ];
45 	} f;
46 	int size, ret, i;
47 
48 	f.handle.handle_bytes = sizeof(f.pad);
49 	size = f.handle.handle_bytes >> 2;
50 
51 	ret = exportfs_encode_inode_fh(inode, (struct fid *)f.handle.f_handle, &size, 0);
52 	if ((ret == FILEID_INVALID) || (ret < 0)) {
53 		WARN_ONCE(1, "Can't encode file handler for inotify: %d\n", ret);
54 		return;
55 	}
56 
57 	f.handle.handle_type = ret;
58 	f.handle.handle_bytes = size * sizeof(u32);
59 
60 	seq_printf(m, "fhandle-bytes:%x fhandle-type:%x f_handle:",
61 		   f.handle.handle_bytes, f.handle.handle_type);
62 
63 	for (i = 0; i < f.handle.handle_bytes; i++)
64 		seq_printf(m, "%02x", (int)f.handle.f_handle[i]);
65 }
66 #else
67 static void show_mark_fhandle(struct seq_file *m, struct inode *inode)
68 {
69 }
70 #endif
71 
72 #ifdef CONFIG_INOTIFY_USER
73 
74 static void inotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
75 {
76 	struct inotify_inode_mark *inode_mark;
77 	struct inode *inode;
78 
79 	if (!(mark->connector->flags & FSNOTIFY_OBJ_TYPE_INODE))
80 		return;
81 
82 	inode_mark = container_of(mark, struct inotify_inode_mark, fsn_mark);
83 	inode = igrab(mark->connector->inode);
84 	if (inode) {
85 		/*
86 		 * IN_ALL_EVENTS represents all of the mask bits
87 		 * that we expose to userspace.  There is at
88 		 * least one bit (FS_EVENT_ON_CHILD) which is
89 		 * used only internally to the kernel.
90 		 */
91 		u32 mask = mark->mask & IN_ALL_EVENTS;
92 		seq_printf(m, "inotify wd:%x ino:%lx sdev:%x mask:%x ignored_mask:%x ",
93 			   inode_mark->wd, inode->i_ino, inode->i_sb->s_dev,
94 			   mask, mark->ignored_mask);
95 		show_mark_fhandle(m, inode);
96 		seq_putc(m, '\n');
97 		iput(inode);
98 	}
99 }
100 
101 void inotify_show_fdinfo(struct seq_file *m, struct file *f)
102 {
103 	show_fdinfo(m, f, inotify_fdinfo);
104 }
105 
106 #endif /* CONFIG_INOTIFY_USER */
107 
108 #ifdef CONFIG_FANOTIFY
109 
110 static void fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
111 {
112 	unsigned int mflags = 0;
113 	struct inode *inode;
114 
115 	if (mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)
116 		mflags |= FAN_MARK_IGNORED_SURV_MODIFY;
117 
118 	if (mark->connector->flags & FSNOTIFY_OBJ_TYPE_INODE) {
119 		inode = igrab(mark->connector->inode);
120 		if (!inode)
121 			return;
122 		seq_printf(m, "fanotify ino:%lx sdev:%x mflags:%x mask:%x ignored_mask:%x ",
123 			   inode->i_ino, inode->i_sb->s_dev,
124 			   mflags, mark->mask, mark->ignored_mask);
125 		show_mark_fhandle(m, inode);
126 		seq_putc(m, '\n');
127 		iput(inode);
128 	} else if (mark->connector->flags & FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
129 		struct mount *mnt = real_mount(mark->connector->mnt);
130 
131 		seq_printf(m, "fanotify mnt_id:%x mflags:%x mask:%x ignored_mask:%x\n",
132 			   mnt->mnt_id, mflags, mark->mask, mark->ignored_mask);
133 	}
134 }
135 
136 void fanotify_show_fdinfo(struct seq_file *m, struct file *f)
137 {
138 	struct fsnotify_group *group = f->private_data;
139 	unsigned int flags = 0;
140 
141 	switch (group->priority) {
142 	case FS_PRIO_0:
143 		flags |= FAN_CLASS_NOTIF;
144 		break;
145 	case FS_PRIO_1:
146 		flags |= FAN_CLASS_CONTENT;
147 		break;
148 	case FS_PRIO_2:
149 		flags |= FAN_CLASS_PRE_CONTENT;
150 		break;
151 	}
152 
153 	if (group->max_events == UINT_MAX)
154 		flags |= FAN_UNLIMITED_QUEUE;
155 
156 	if (group->fanotify_data.max_marks == UINT_MAX)
157 		flags |= FAN_UNLIMITED_MARKS;
158 
159 	seq_printf(m, "fanotify flags:%x event-flags:%x\n",
160 		   flags, group->fanotify_data.f_flags);
161 
162 	show_fdinfo(m, f, fanotify_fdinfo);
163 }
164 
165 #endif /* CONFIG_FANOTIFY */
166 
167 #endif /* CONFIG_INOTIFY_USER || CONFIG_FANOTIFY */
168 
169 #endif /* CONFIG_PROC_FS */
170