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#include <errno.h>
#include <libgen.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/statfs.h>
#include <unistd.h>
#include <dirent.h>
#include <ctype.h>
#include "applypatch.h"
static int EliminateOpenFiles(char** files, int file_count) {
DIR* d;
struct dirent* de;
d = opendir("/proc");
if (d == NULL) {
printf("error opening /proc: %s\n", strerror(errno));
return -1;
}
while ((de = readdir(d)) != 0) {
int i;
for (i = 0; de->d_name[i] != '\0' && isdigit(de->d_name[i]); ++i);
if (de->d_name[i]) continue;
// de->d_name[i] is numeric
char path[FILENAME_MAX];
strcpy(path, "/proc/");
strcat(path, de->d_name);
strcat(path, "/fd/");
DIR* fdd;
struct dirent* fdde;
fdd = opendir(path);
if (fdd == NULL) {
printf("error opening %s: %s\n", path, strerror(errno));
continue;
}
while ((fdde = readdir(fdd)) != 0) {
char fd_path[FILENAME_MAX];
char link[FILENAME_MAX];
strcpy(fd_path, path);
strcat(fd_path, fdde->d_name);
int count;
count = readlink(fd_path, link, sizeof(link)-1);
if (count >= 0) {
link[count] = '\0';
// This is inefficient, but it should only matter if there are
// lots of files in /cache, and lots of them are open (neither
// of which should be true, especially in recovery).
if (strncmp(link, "/cache/", 7) == 0) {
int j;
for (j = 0; j < file_count; ++j) {
if (files[j] && strcmp(files[j], link) == 0) {
printf("%s is open by %s\n", link, de->d_name);
free(files[j]);
files[j] = NULL;
}
}
}
}
}
closedir(fdd);
}
closedir(d);
return 0;
}
int FindExpendableFiles(char*** names, int* entries) {
DIR* d;
struct dirent* de;
int size = 32;
*entries = 0;
*names = malloc(size * sizeof(char*));
char path[FILENAME_MAX];
// We're allowed to delete unopened regular files in any of these
// directories.
const char* dirs[2] = {"/cache", "/cache/recovery/otatest"};
unsigned int i;
for (i = 0; i < sizeof(dirs)/sizeof(dirs[0]); ++i) {
d = opendir(dirs[i]);
if (d == NULL) {
printf("error opening %s: %s\n", dirs[i], strerror(errno));
continue;
}
// Look for regular files in the directory (not in any subdirectories).
while ((de = readdir(d)) != 0) {
strcpy(path, dirs[i]);
strcat(path, "/");
strcat(path, de->d_name);
// We can't delete CACHE_TEMP_SOURCE; if it's there we might have
// restarted during installation and could be depending on it to
// be there.
if (strcmp(path, CACHE_TEMP_SOURCE) == 0) continue;
struct stat st;
if (stat(path, &st) == 0 && S_ISREG(st.st_mode)) {
if (*entries >= size) {
size *= 2;
*names = realloc(*names, size * sizeof(char*));
}
(*names)[(*entries)++] = strdup(path);
}
}
closedir(d);
}
printf("%d regular files in deletable directories\n", *entries);
if (EliminateOpenFiles(*names, *entries) < 0) {
return -1;
}
return 0;
}
int MakeFreeSpaceOnCache(size_t bytes_needed) {
size_t free_now = FreeSpaceForFile("/cache");
printf("%ld bytes free on /cache (%ld needed)\n",
(long)free_now, (long)bytes_needed);
if (free_now >= bytes_needed) {
return 0;
}
char** names;
int entries;
if (FindExpendableFiles(&names, &entries) < 0) {
return -1;
}
if (entries == 0) {
// nothing we can delete to free up space!
printf("no files can be deleted to free space on /cache\n");
return -1;
}
// We could try to be smarter about which files to delete: the
// biggest ones? the smallest ones that will free up enough space?
// the oldest? the newest?
//
// Instead, we'll be dumb.
int i;
for (i = 0; i < entries && free_now < bytes_needed; ++i) {
if (names[i]) {
unlink(names[i]);
free_now = FreeSpaceForFile("/cache");
printf("deleted %s; now %ld bytes free\n", names[i], (long)free_now);
free(names[i]);
}
}
for (; i < entries; ++i) {
free(names[i]);
}
free(names);
return (free_now >= bytes_needed) ? 0 : -1;
}
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