return rc;
}
-static int __table_parse_stream(struct libmnt_table *tb, FILE *f, const char *filename)
+/**
+ * mnt_table_parse_stream:
+ * @tb: tab pointer
+ * @f: file stream
+ * @filename: filename used for debug and error messages
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_table_parse_stream(struct libmnt_table *tb, FILE *f, const char *filename)
{
int rc = -1;
int flags = 0;
return rc;
}
-/**
- * mnt_table_parse_stream:
- * @tb: tab pointer
- * @f: file stream
- * @filename: filename used for debug and error messages
- *
- * Returns: 0 on success, negative number in case of error.
- */
-int mnt_table_parse_stream(struct libmnt_table *tb, FILE *f, const char *filename)
-{
- int fd, rc;
- FILE *memf = NULL;
- char *membuf = NULL;
-
- /*
- * For /proc/#/{mountinfo,mount} we read all file to memory and use it
- * as memory stream. For more details see mnt_read_procfs_file().
- */
- if ((fd = fileno(f)) >= 0
- && (tb->fmt == MNT_FMT_GUESS ||
- tb->fmt == MNT_FMT_MOUNTINFO ||
- tb->fmt == MNT_FMT_MTAB)
- && is_procfs_fd(fd)
- && (memf = mnt_get_procfs_memstream(fd, &membuf))) {
-
- rc = __table_parse_stream(tb, memf, filename);
- fclose(memf);
- free(membuf);
- } else
- rc = __table_parse_stream(tb, f, filename);
-
- return rc;
-}
-
/**
* mnt_table_parse_file:
* @tb: tab pointer
int mnt_table_parse_file(struct libmnt_table *tb, const char *filename)
{
FILE *f;
- int rc, fd = -1;
+ int rc;
if (!filename || !tb)
return -EINVAL;
- /*
- * Try to use read()+poll() to realiably read all
- * /proc/#/{mount,mountinfo} file to memory
- */
- if (tb->fmt != MNT_FMT_SWAPS
- && strncmp(filename, "/proc/", 6) == 0) {
-
- FILE *memf;
- char *membuf = NULL;
-
- fd = open(filename, O_RDONLY|O_CLOEXEC);
- if (fd < 0) {
- rc = -errno;
- goto done;
- }
- memf = mnt_get_procfs_memstream(fd, &membuf);
- if (memf) {
- rc = __table_parse_stream(tb, memf, filename);
-
- fclose(memf);
- free(membuf);
- close(fd);
- goto done;
- }
- /* else fallback to fopen/fdopen() */
- }
-
- if (fd >= 0)
- f = fdopen(fd, "r" UL_CLOEXECSTR);
- else
- f = fopen(filename, "r" UL_CLOEXECSTR);
-
+ f = fopen(filename, "r" UL_CLOEXECSTR);
if (f) {
- rc = __table_parse_stream(tb, f, filename);
+ rc = mnt_table_parse_stream(tb, f, filename);
fclose(f);
} else
rc = -errno;
-done:
+
DBG(TAB, ul_debugobj(tb, "parsing done [filename=%s, rc=%d]", filename, rc));
return rc;
}
f = fopen_at(dd, d->d_name, O_RDONLY|O_CLOEXEC, "r" UL_CLOEXECSTR);
if (f) {
- __table_parse_stream(tb, f, d->d_name);
+ mnt_table_parse_stream(tb, f, d->d_name);
fclose(f);
}
}
f = fopen_at(dirfd(dir), d->d_name,
O_RDONLY|O_CLOEXEC, "r" UL_CLOEXECSTR);
if (f) {
- __table_parse_stream(tb, f, d->d_name);
+ mnt_table_parse_stream(tb, f, d->d_name);
fclose(f);
}
}
#include <fcntl.h>
#include <pwd.h>
#include <grp.h>
-#include <poll.h>
#include <blkid.h>
#include "strutils.h"
return NULL;
}
-int is_procfs_fd(int fd)
-{
- struct statfs sfs;
-
- return fstatfs(fd, &sfs) == 0 && sfs.f_type == STATFS_PROC_MAGIC;
-}
-
/**
* mnt_match_fstype:
* @type: filesystem type
return 1;
}
-#if defined(HAVE_FMEMOPEN) || defined(TEST_PROGRAM)
-
-/*
- * This function tries to minimize possible races when we read
- * /proc/#/{mountinfo,mount} files.
- *
- * The idea is to minimize number of read()s and check by poll() that during
- * the read the mount table has not been modified. If yes, than re-read it
- * (with some limitations to avoid never ending loop).
- *
- * Returns: <0 error, 0 success, 1 too many attempts
- */
-static int read_procfs_file(int fd, char **buf, size_t *bufsiz)
-{
- size_t bufmax = 0;
- int rc = 0, tries = 0, ninters = 0;
- char *bufptr = NULL;
-
- assert(buf);
- assert(bufsiz);
-
- *bufsiz = 0;
- *buf = NULL;
-
- do {
- ssize_t ret;
-
- if (!bufptr || bufmax == *bufsiz) {
- char *tmp;
-
- bufmax = bufmax ? bufmax * 2 : (16 * 1024);
- tmp = realloc(*buf, bufmax);
- if (!tmp)
- break;
- *buf = tmp;
- bufptr = tmp + *bufsiz;
- }
-
- errno = 0;
- ret = read(fd, bufptr, bufmax - *bufsiz);
-
- if (ret < 0) {
- /* error */
- if ((errno == EAGAIN || errno == EINTR) && (ninters++ < 5)) {
- xusleep(200000);
- continue;
- }
- break;
-
- } if (ret > 0) {
- /* success -- verify no event during read */
- struct pollfd fds[] = {
- { .fd = fd, .events = POLLPRI }
- };
-
- rc = poll(fds, 1, 0);
- if (rc < 0)
- break; /* poll() error */
- if (rc > 0) {
- /* event -- read all again */
- if (lseek(fd, 0, SEEK_SET) != 0)
- break;
- *bufsiz = 0;
- bufptr = *buf;
- tries++;
-
- if (tries > 10)
- /* busy system? -- wait */
- xusleep(10000);
- continue;
- }
-
- /* successful read() without active poll() */
- (*bufsiz) += (size_t) ret;
- bufptr += ret;
- tries = ninters = 0;
- } else {
- /* end-of-file */
- goto success;
- }
- } while (tries <= 100);
-
- rc = errno ? -errno : 1;
- free(*buf);
- return rc;
-
-success:
- return 0;
-}
-
-/*
- * Create FILE stream for data from read_procfs_file()
- */
-FILE *mnt_get_procfs_memstream(int fd, char **membuf)
-{
- size_t sz = 0;
- off_t cur;
-
- *membuf = NULL;
-
- /* in case of error, rewind to the original position */
- cur = lseek(fd, 0, SEEK_CUR);
-
- if (read_procfs_file(fd, membuf, &sz) == 0 && sz > 0) {
- FILE *memf = fmemopen(*membuf, sz, "r");
- if (memf)
- return memf; /* success */
-
- free(*membuf);
- *membuf = NULL;
- }
-
- /* error */
- if (cur != (off_t) -1)
- lseek(fd, cur, SEEK_SET);
- return NULL;
-}
-#else
-FILE *mnt_get_procfs_memstream(int fd __attribute((__unused__)),
- char **membuf __attribute((__unused__)))
-{
- return NULL;
-}
-#endif /* HAVE_FMEMOPEN */
-
-
#ifdef TEST_PROGRAM
-static int test_proc_read(struct libmnt_test *ts, int argc, char *argv[])
-{
- char *buf = NULL;
- char *filename = argv[1];
- size_t bufsiz = 0;
- int rc = 0, fd = open(filename, O_RDONLY);
-
- if (fd <= 0) {
- warn("%s: cannot open", filename);
- return -errno;
- }
-
- rc = read_procfs_file(fd, &buf, &bufsiz);
- close(fd);
-
- switch (rc) {
- case 0:
- fwrite(buf, 1, bufsiz, stdout);
- free(buf);
- break;
- case 1:
- warnx("too many attempts");
- break;
- default:
- warn("%s: cannot read", filename);
- break;
- }
-
- return rc;
-}
-
static int test_match_fstype(struct libmnt_test *ts, int argc, char *argv[])
{
char *type = argv[1];
{ "--guess-root", test_guess_root, "[<maj:min>]" },
{ "--mkdir", test_mkdir, "<path>" },
{ "--statfs-type", test_statfs_type, "<path>" },
- { "--read-procfs", test_proc_read, "<path>" },
{ NULL }
};
projects / thirdparty / util-linux.git / commitdiff
