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sd-journal: when picking up a new file, compare inode/device info with previous open file by same name

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Let's make sure we aren't confused if a journal file is replaced by a
different one (for example due to rotation) if we are in a q overflow:
let's compare the inode/device information, and if it changed replace
any open file object as needed.

Fixes: #8198
This commit is contained in:
Lennart Poettering 2018-02-19 17:42:47 +01:00
parent fc1813c0fe
commit 9c66f52813
1 changed files with 91 additions and 42 deletions
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133
src/journal/sd-journal.c
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@ -1243,6 +1243,16 @@ static bool path_has_prefix(sd_journal *j, const char *path, const char *prefix)
return path_startswith(path, prefix);
}
static void track_file_disposition(sd_journal *j, JournalFile *f) {
assert(j);
assert(f);
if (!j->has_runtime_files && path_has_prefix(j, f->path, "/run"))
j->has_runtime_files = true;
else if (!j->has_persistent_files && path_has_prefix(j, f->path, "/var"))
j->has_persistent_files = true;
}
static const char *skip_slash(const char *p) {
if (!p)
@ -1254,81 +1264,120 @@ static const char *skip_slash(const char *p) {
return p;
}
static int add_any_file(sd_journal *j, int fd, const char *path) {
JournalFile *f = NULL;
static int add_any_file(
sd_journal *j,
int fd,
const char *path) {
bool close_fd = false;
JournalFile *f;
struct stat st;
int r, k;
assert(j);
assert(fd >= 0 || path);
if (path) {
f = ordered_hashmap_get(j->files, path);
if (f) {
/* Mark this file as seen in this generation. This is used to GC old files in
* process_q_overflow() to detect journal files that are still and discern them from those who
* are gone. */
f->last_seen_generation = j->generation;
return 0;
if (fd < 0) {
if (j->toplevel_fd >= 0)
/* If there's a top-level fd defined make the path relative, explicitly, since otherwise
* openat() ignores the first argument. */
fd = openat(j->toplevel_fd, skip_slash(path), O_RDONLY|O_CLOEXEC|O_NONBLOCK);
else
fd = open(path, O_RDONLY|O_CLOEXEC|O_NONBLOCK);
if (fd < 0) {
r = log_debug_errno(errno, "Failed to open journal file %s: %m", path);
goto finish;
}
close_fd = true;
r = fd_nonblock(fd, false);
if (r < 0) {
r = log_debug_errno(errno, "Failed to turn off O_NONBLOCK for %s: %m", path);
goto finish;
}
}
if (fstat(fd, &st) < 0) {
r = log_debug_errno(errno, "Failed to fstat file '%s': %m", path);
goto finish;
}
if (S_ISDIR(st.st_mode)) {
log_debug("Uh, file '%s' is a directory? Refusing.", path);
r = -EISDIR;
goto finish;
}
if (!S_ISREG(st.st_mode)) {
log_debug("Uh, file '%s' is not a regular file? Refusing.", path);
r = -EBADFD;
goto finish;
}
f = ordered_hashmap_get(j->files, path);
if (f) {
if (f->last_stat.st_dev == st.st_dev &&
f->last_stat.st_ino == st.st_ino) {
/* We already track this file, under the same path and with the same device/inode numbers, it's
* hence really the same. Mark this file as seen in this generation. This is used to GC old
* files in process_q_overflow() to detect journal files that are still there and discern them
* from those which are gone. */
f->last_seen_generation = j->generation;
r = 0;
goto finish;
}
/* So we tracked a file under this name, but it has a different inode/device. In that case, it got
* replaced (probably due to rotation?), let's drop it hence from our list. */
remove_file_real(j, f);
f = NULL;
}
if (ordered_hashmap_size(j->files) >= JOURNAL_FILES_MAX) {
log_debug("Too many open journal files, not adding %s.", path);
r = -ETOOMANYREFS;
goto fail;
}
if (fd < 0 && j->toplevel_fd >= 0) {
/* If there's a top-level fd defined, open the file relative to this now. (Make the path relative,
* explicitly, since otherwise openat() ignores the first argument.) */
fd = openat(j->toplevel_fd, skip_slash(path), O_RDONLY|O_CLOEXEC);
if (fd < 0) {
r = log_debug_errno(errno, "Failed to open journal file %s: %m", path);
goto fail;
}
close_fd = true;
goto finish;
}
r = journal_file_open(fd, path, O_RDONLY, 0, false, false, NULL, j->mmap, NULL, NULL, &f);
if (r < 0) {
if (close_fd)
safe_close(fd);
log_debug_errno(r, "Failed to open journal file %s: %m", path);
goto fail;
goto finish;
}
/* journal_file_dump(f); */
r = ordered_hashmap_put(j->files, f->path, f);
if (r < 0) {
f->close_fd = close_fd;
f->close_fd = false; /* make sure journal_file_close() doesn't close the caller's fd (or our own). We'll let the caller do that, or ourselves */
(void) journal_file_close(f);
goto fail;
goto finish;
}
close_fd = false; /* the fd is now owned by the JournalFile object */
f->last_seen_generation = j->generation;
if (!j->has_runtime_files && path_has_prefix(j, f->path, "/run"))
j->has_runtime_files = true;
else if (!j->has_persistent_files && path_has_prefix(j, f->path, "/var"))
j->has_persistent_files = true;
log_debug("File %s added.", f->path);
track_file_disposition(j, f);
check_network(j, f->fd);
j->current_invalidate_counter++;
return 0;
log_debug("File %s added.", f->path);
fail:
k = journal_put_error(j, r, path);
if (k < 0)
return k;
r = 0;
finish:
if (close_fd)
safe_close(fd);
if (r < 0) {
k = journal_put_error(j, r, path);
if (k < 0)
return k;
}
return r;
}