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
40static unsigned long long get_boot_time_ms(void)
41{
42    struct timespec t;
43    unsigned long long time_ms;
44
45    t.tv_sec = 0;
46    t.tv_nsec = 0;
47    clock_gettime(CLOCK_BOOTTIME, &t);
48    time_ms = (t.tv_sec * 1000LL) + (t.tv_nsec / 1000000);
49
50    return time_ms;
51}
52
53static void *do_fstrim_filesystems(void *ignored)
54{
55    int i;
56    int fd;
57    int ret = 0;
58    struct fstrim_range range = { 0 };
59    struct stat sb;
60    extern struct fstab *fstab;
61
62    SLOGI("Starting fstrim work...\n");
63
64    /* Log the start time in the event log */
65    LOG_EVENT_LONG(LOG_FSTRIM_START, get_boot_time_ms());
66
67    for (i = 0; i < fstab->num_entries; i++) {
68        /* Skip raw partitions */
69        if (!strcmp(fstab->recs[i].fs_type, "emmc") ||
70            !strcmp(fstab->recs[i].fs_type, "mtd")) {
71            continue;
72        }
73        /* Skip read-only filesystems */
74        if (fstab->recs[i].flags & MS_RDONLY) {
75            continue;
76        }
77        if (fs_mgr_is_voldmanaged(&fstab->recs[i])) {
78            continue; /* Should we trim fat32 filesystems? */
79        }
80
81        if (stat(fstab->recs[i].mount_point, &sb) == -1) {
82            SLOGE("Cannot stat mount point %s\n", fstab->recs[i].mount_point);
83            ret = -1;
84            continue;
85        }
86        if (!S_ISDIR(sb.st_mode)) {
87            SLOGE("%s is not a directory\n", fstab->recs[i].mount_point);
88            ret = -1;
89            continue;
90        }
91
92        fd = open(fstab->recs[i].mount_point, O_RDONLY);
93        if (fd < 0) {
94            SLOGE("Cannot open %s for FITRIM\n", fstab->recs[i].mount_point);
95            ret = -1;
96            continue;
97        }
98
99        memset(&range, 0, sizeof(range));
100        range.len = ULLONG_MAX;
101        SLOGI("Invoking FITRIM ioctl on %s", fstab->recs[i].mount_point);
102        if (ioctl(fd, FITRIM, &range)) {
103            SLOGE("FITRIM ioctl failed on %s", fstab->recs[i].mount_point);
104            ret = -1;
105        } else {
106            SLOGI("Trimmed %llu bytes on %s\n", range.len, fstab->recs[i].mount_point);
107        }
108        close(fd);
109    }
110
111    /* Log the finish time in the event log */
112    LOG_EVENT_LONG(LOG_FSTRIM_FINISH, get_boot_time_ms());
113
114    SLOGI("Finished fstrim work.\n");
115
116    /* Release the wakelock that let us work */
117    release_wake_lock(FSTRIM_WAKELOCK);
118
119    return (void *)ret;
120}
121
122int fstrim_filesystems(void)
123{
124    pthread_t t;
125    int ret;
126
127    /* Get a wakelock as this may take a while, and we don't want the
128     * device to sleep on us.
129     */
130    acquire_wake_lock(PARTIAL_WAKE_LOCK, FSTRIM_WAKELOCK);
131
132    /* Depending on the emmc chip and size, this can take upwards
133     * of a few minutes.  If done in the same thread as the caller
134     * of this function, that would block vold from accepting any
135     * commands until the trim is finished.  So start another thread
136     * to do the work, and return immediately.
137     *
138     * This function should not be called more than once per day, but
139     * even if it is called a second time before the first one finishes,
140     * the kernel will "do the right thing" and split the work between
141     * the two ioctls invoked in separate threads.
142     */
143    ret = pthread_create(&t, NULL, do_fstrim_filesystems, NULL);
144    if (ret) {
145        SLOGE("Cannot create thread to do fstrim");
146        return ret;
147    }
148
149    ret = pthread_detach(t);
150    if (ret) {
151        SLOGE("Cannot detach thread doing fstrim");
152        return ret;
153    }
154
155    return 0;
156}
157