1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <sys/types.h>
18#include <sys/stat.h>
19#include <fcntl.h>
20#include <unistd.h>
21#include <sys/ioctl.h>
22#include <string.h>
23#include <limits.h>
24#include <linux/fs.h>
25#include <time.h>
26#include <fs_mgr.h>
27#include <pthread.h>
28#define LOG_TAG "fstrim"
29#include "cutils/log.h"
30#include "hardware_legacy/power.h"
31
32/* These numbers must match what the MountService specified in
33 * frameworks/base/services/java/com/android/server/EventLogTags.logtags
34 */
35#define LOG_FSTRIM_START  2755
36#define LOG_FSTRIM_FINISH 2756
37
38#define FSTRIM_WAKELOCK "dofstrim"
39
40#define UNUSED __attribute__((unused))
41
42/* From a would-be kernel header */
43#define FIDTRIM         _IOWR('f', 128, struct fstrim_range)    /* Deep discard trim */
44
45static unsigned long long get_boot_time_ms(void)
46{
47    struct timespec t;
48    unsigned long long time_ms;
49
50    t.tv_sec = 0;
51    t.tv_nsec = 0;
52    clock_gettime(CLOCK_BOOTTIME, &t);
53    time_ms = (t.tv_sec * 1000LL) + (t.tv_nsec / 1000000);
54
55    return time_ms;
56}
57
58static void *do_fstrim_filesystems(void *thread_arg)
59{
60    int i;
61    int fd;
62    int ret = 0;
63    struct fstrim_range range = { 0 };
64    struct stat sb;
65    extern struct fstab *fstab;
66    int deep_trim = !!thread_arg;
67
68    SLOGI("Starting fstrim work...\n");
69
70    /* Log the start time in the event log */
71    LOG_EVENT_LONG(LOG_FSTRIM_START, get_boot_time_ms());
72
73    for (i = 0; i < fstab->num_entries; i++) {
74        /* Skip raw partitions */
75        if (!strcmp(fstab->recs[i].fs_type, "emmc") ||
76            !strcmp(fstab->recs[i].fs_type, "mtd")) {
77            continue;
78        }
79        /* Skip read-only filesystems */
80        if (fstab->recs[i].flags & MS_RDONLY) {
81            continue;
82        }
83        if (fs_mgr_is_voldmanaged(&fstab->recs[i])) {
84            continue; /* Should we trim fat32 filesystems? */
85        }
86
87        if (stat(fstab->recs[i].mount_point, &sb) == -1) {
88            SLOGE("Cannot stat mount point %s\n", fstab->recs[i].mount_point);
89            ret = -1;
90            continue;
91        }
92        if (!S_ISDIR(sb.st_mode)) {
93            SLOGE("%s is not a directory\n", fstab->recs[i].mount_point);
94            ret = -1;
95            continue;
96        }
97
98        fd = open(fstab->recs[i].mount_point, O_RDONLY);
99        if (fd < 0) {
100            SLOGE("Cannot open %s for FITRIM\n", fstab->recs[i].mount_point);
101            ret = -1;
102            continue;
103        }
104
105        memset(&range, 0, sizeof(range));
106        range.len = ULLONG_MAX;
107        SLOGI("Invoking %s ioctl on %s", deep_trim ? "FIDTRIM" : "FITRIM", fstab->recs[i].mount_point);
108
109        ret = ioctl(fd, deep_trim ? FIDTRIM : FITRIM, &range);
110        if (ret) {
111            SLOGE("%s ioctl failed on %s (error %d/%s)", deep_trim ? "FIDTRIM" : "FITRIM", fstab->recs[i].mount_point, errno, strerror(errno));
112            ret = -1;
113        } else {
114            SLOGI("Trimmed %llu bytes on %s\n", range.len, fstab->recs[i].mount_point);
115        }
116        close(fd);
117    }
118
119    /* Log the finish time in the event log */
120    LOG_EVENT_LONG(LOG_FSTRIM_FINISH, get_boot_time_ms());
121
122    SLOGI("Finished fstrim work.\n");
123
124    /* Release the wakelock that let us work */
125    release_wake_lock(FSTRIM_WAKELOCK);
126
127    return (void *)(uintptr_t)ret;
128}
129
130int fstrim_filesystems(int deep_trim)
131{
132    pthread_t t;
133    int ret;
134
135    /* Get a wakelock as this may take a while, and we don't want the
136     * device to sleep on us.
137     */
138    acquire_wake_lock(PARTIAL_WAKE_LOCK, FSTRIM_WAKELOCK);
139
140    /* Depending on the emmc chip and size, this can take upwards
141     * of a few minutes.  If done in the same thread as the caller
142     * of this function, that would block vold from accepting any
143     * commands until the trim is finished.  So start another thread
144     * to do the work, and return immediately.
145     *
146     * This function should not be called more than once per day, but
147     * even if it is called a second time before the first one finishes,
148     * the kernel will "do the right thing" and split the work between
149     * the two ioctls invoked in separate threads.
150     */
151    ret = pthread_create(&t, NULL, do_fstrim_filesystems, (void *)(intptr_t)deep_trim);
152    if (ret) {
153        SLOGE("Cannot create thread to do fstrim");
154        return ret;
155    }
156
157    ret = pthread_detach(t);
158    if (ret) {
159        SLOGE("Cannot detach thread doing fstrim");
160        return ret;
161    }
162
163    return 0;
164}
165