journal: remove journal_file_object_keep/release functions

The only user is sd_journal_enumerate_unique() and, as explained in
the previous commit (fed67c38e3 "journal: map objects to context set by
caller, not by actual object type"), the use of them there is now
superfluous. Let's remove them.

This reverts major parts of commits:
  ae97089d49 journal: fix access to munmapped memory in
             sd_journal_enumerate_unique
  06cc69d44c sd-journal: fix sd_journal_enumerate_unique skipping values

Tested with an "--enable-debug" build and "journalctl --list-boots".
It gives the expected number of results. Additionally, if I then revert
the previous commit ("journal: map objects to context set by caller, not
to actual object type"), it crashes with SIGSEGV, as expected.

7 files changed, 24 insertions, 92 deletions

diff --git a/src/journal/journal-file.c b/src/journal/journal-file.c
index 01b7f89fef..f70699010e 100644
--- a/src/journal/journal-file.c
+++ b/src/journal/journal-file.c
@@ -391,7 +391,7 @@ static int journal_file_move_to(JournalFile *f, int context, bool keep_always, u
                         return -EADDRNOTAVAIL;
         }
 
-        return mmap_cache_get(f->mmap, f->fd, f->prot, context, keep_always, offset, size, &f->last_stat, ret, NULL);
+        return mmap_cache_get(f->mmap, f->fd, f->prot, context, keep_always, offset, size, &f->last_stat, ret);
 }
 
 static uint64_t minimum_header_size(Object *o) {
diff --git a/src/journal/journal-file.h b/src/journal/journal-file.h
index 211e121d5c..c5a92bc5ff 100644
--- a/src/journal/journal-file.h
+++ b/src/journal/journal-file.h
@@ -211,15 +211,3 @@ static unsigned type_to_context(int type) {
         /* One context for each type, plus one catch-all for the rest */
         return type > 0 && type < _OBJECT_TYPE_MAX ? type : 0;
 }
-
-static inline int journal_file_object_keep(JournalFile *f, Object *o, uint64_t offset, void **release_cookie) {
-        unsigned context = type_to_context(o->object.type);
-        uint64_t s = le64toh(o->object.size);
-
-        return mmap_cache_get(f->mmap, f->fd, f->prot, context, true,
-                              offset, s, &f->last_stat, NULL, release_cookie);
-}
-
-static inline int journal_file_object_release(JournalFile *f, void *release_cookie) {
-        return mmap_cache_release(f->mmap, f->fd, release_cookie);
-}
diff --git a/src/journal/journal-verify.c b/src/journal/journal-verify.c
index 91de45f144..75792a5a60 100644
--- a/src/journal/journal-verify.c
+++ b/src/journal/journal-verify.c
@@ -368,7 +368,7 @@ static int contains_uint64(MMapCache *m, int fd, uint64_t n, uint64_t p) {
 
                 c = (a + b) / 2;
 
-                r = mmap_cache_get(m, fd, PROT_READ|PROT_WRITE, 0, false, c * sizeof(uint64_t), sizeof(uint64_t), NULL, (void **) &z, NULL);
+                r = mmap_cache_get(m, fd, PROT_READ|PROT_WRITE, 0, false, c * sizeof(uint64_t), sizeof(uint64_t), NULL, (void **) &z);
                 if (r < 0)
                         return r;
 
diff --git a/src/journal/mmap-cache.c b/src/journal/mmap-cache.c
index c57c1623c5..f34d260856 100644
--- a/src/journal/mmap-cache.c
+++ b/src/journal/mmap-cache.c
@@ -38,7 +38,7 @@ typedef struct FileDescriptor FileDescriptor;
 struct Window {
         MMapCache *cache;
 
-        unsigned keep_always;
+        bool keep_always;
         bool in_unused;
 
         int prot;
@@ -191,7 +191,7 @@ static void context_detach_window(Context *c) {
         c->window = NULL;
         LIST_REMOVE(by_window, w->contexts, c);
 
-        if (!w->contexts && w->keep_always == 0) {
+        if (!w->contexts && !w->keep_always) {
                 /* Not used anymore? */
 #ifdef ENABLE_DEBUG_MMAP_CACHE
                 /* Unmap unused windows immediately to expose use-after-unmap
@@ -364,8 +364,7 @@ static int try_context(
                 bool keep_always,
                 uint64_t offset,
                 size_t size,
-                void **ret,
-                void **release_cookie) {
+                void **ret) {
 
         Context *c;
 
@@ -373,6 +372,7 @@ static int try_context(
         assert(m->n_ref > 0);
         assert(fd >= 0);
         assert(size > 0);
+        assert(ret);
 
         c = hashmap_get(m->contexts, UINT_TO_PTR(context+1));
         if (!c)
@@ -390,12 +390,9 @@ static int try_context(
                 return 0;
         }
 
-        c->window->keep_always += keep_always;
+        c->window->keep_always |= keep_always;
 
-        if (ret)
-                *ret = (uint8_t*) c->window->ptr + (offset - c->window->offset);
-        if (keep_always && release_cookie)
-                *release_cookie = c->window;
+        *ret = (uint8_t*) c->window->ptr + (offset - c->window->offset);
         return 1;
 }
 
@@ -407,8 +404,7 @@ static int find_mmap(
                 bool keep_always,
                 uint64_t offset,
                 size_t size,
-                void **ret,
-                void **release_cookie) {
+                void **ret) {
 
         FileDescriptor *f;
         Window *w;
@@ -439,10 +435,7 @@ static int find_mmap(
         context_attach_window(c, w);
         w->keep_always += keep_always;
 
-        if (ret)
-                *ret = (uint8_t*) w->ptr + (offset - w->offset);
-        if (keep_always && release_cookie)
-                *release_cookie = c->window;
+        *ret = (uint8_t*) w->ptr + (offset - w->offset);
         return 1;
 }
 
@@ -455,8 +448,7 @@ static int add_mmap(
                 uint64_t offset,
                 size_t size,
                 struct stat *st,
-                void **ret,
-                void **release_cookie) {
+                void **ret) {
 
         uint64_t woffset, wsize;
         Context *c;
@@ -469,6 +461,7 @@ static int add_mmap(
         assert(m->n_ref > 0);
         assert(fd >= 0);
         assert(size > 0);
+        assert(ret);
 
         woffset = offset & ~((uint64_t) page_size() - 1ULL);
         wsize = size + (offset - woffset);
@@ -538,10 +531,7 @@ static int add_mmap(
         c->window = w;
         LIST_PREPEND(by_window, w->contexts, c);
 
-        if (ret)
-                *ret = (uint8_t*) w->ptr + (offset - w->offset);
-        if (keep_always && release_cookie)
-                *release_cookie = c->window;
+        *ret = (uint8_t*) w->ptr + (offset - w->offset);
         return 1;
 
 outofmem:
@@ -558,8 +548,7 @@ int mmap_cache_get(
                 uint64_t offset,
                 size_t size,
                 struct stat *st,
-                void **ret,
-                void **release_cookie) {
+                void **ret) {
 
         int r;
 
@@ -567,16 +556,17 @@ int mmap_cache_get(
         assert(m->n_ref > 0);
         assert(fd >= 0);
         assert(size > 0);
+        assert(ret);
 
         /* Check whether the current context is the right one already */
-        r = try_context(m, fd, prot, context, keep_always, offset, size, ret, release_cookie);
+        r = try_context(m, fd, prot, context, keep_always, offset, size, ret);
         if (r != 0) {
                 m->n_hit ++;
                 return r;
         }
 
         /* Search for a matching mmap */
-        r = find_mmap(m, fd, prot, context, keep_always, offset, size, ret, release_cookie);
+        r = find_mmap(m, fd, prot, context, keep_always, offset, size, ret);
         if (r != 0) {
                 m->n_hit ++;
                 return r;
@@ -585,39 +575,7 @@ int mmap_cache_get(
         m->n_missed++;
 
         /* Create a new mmap */
-        return add_mmap(m, fd, prot, context, keep_always, offset, size, st, ret, release_cookie);
-}
-
-int mmap_cache_release(
-                MMapCache *m,
-                int fd,
-                void *release_cookie) {
-
-        FileDescriptor *f;
-        Window *w;
-
-        assert(m);
-        assert(m->n_ref > 0);
-        assert(fd >= 0);
-
-        f = hashmap_get(m->fds, INT_TO_PTR(fd + 1));
-        if (!f)
-                return -EBADF;
-
-        assert(f->fd == fd);
-
-        LIST_FOREACH(by_fd, w, f->windows)
-                if (w == release_cookie)
-                        break;
-
-        if (!w)
-                return -ENOENT;
-
-        if (w->keep_always == 0)
-                return -ENOLCK;
-
-        w->keep_always -= 1;
-        return 0;
+        return add_mmap(m, fd, prot, context, keep_always, offset, size, st, ret);
 }
 
 void mmap_cache_close_fd(MMapCache *m, int fd) {
diff --git a/src/journal/mmap-cache.h b/src/journal/mmap-cache.h
index 76e5316248..3e2ffbbfd1 100644
--- a/src/journal/mmap-cache.h
+++ b/src/journal/mmap-cache.h
@@ -40,12 +40,7 @@ int mmap_cache_get(
         uint64_t offset,
         size_t size,
         struct stat *st,
-        void **ret,
-        void **release_cookie);
-int mmap_cache_release(
-        MMapCache *m,
-        int fd,
-        void *release_cookie);
+        void **ret);
 void mmap_cache_close_fd(MMapCache *m, int fd);
 void mmap_cache_close_context(MMapCache *m, unsigned context);
 
diff --git a/src/journal/sd-journal.c b/src/journal/sd-journal.c
index 23aad740dd..028060d348 100644
--- a/src/journal/sd-journal.c
+++ b/src/journal/sd-journal.c
@@ -2563,7 +2563,6 @@ _public_ int sd_journal_enumerate_unique(sd_journal *j, const void **data, size_
                 size_t ol;
                 bool found;
                 int r;
-                void *release_cookie;
 
                 /* Proceed to next data object in the field's linked list */
                 if (j->unique_offset == 0) {
@@ -2604,10 +2603,6 @@ _public_ int sd_journal_enumerate_unique(sd_journal *j, const void **data, size_
                         return -EBADMSG;
                 }
 
-                r = journal_file_object_keep(j->unique_file, o, j->unique_offset, &release_cookie);
-                if (r < 0)
-                        return r;
-
                 r = return_data(j, j->unique_file, o, &odata, &ol);
                 if (r < 0)
                         return r;
@@ -2652,10 +2647,6 @@ _public_ int sd_journal_enumerate_unique(sd_journal *j, const void **data, size_
                                 found = true;
                 }
 
-                r = journal_file_object_release(j->unique_file, release_cookie);
-                if (r < 0)
-                        return r;
-
                 if (found)
                         continue;
 
diff --git a/src/journal/test-mmap-cache.c b/src/journal/test-mmap-cache.c
index 1227b62310..3fcd77475d 100644
--- a/src/journal/test-mmap-cache.c
+++ b/src/journal/test-mmap-cache.c
@@ -49,23 +49,23 @@ int main(int argc, char *argv[]) {
         assert_se(z >= 0);
         unlink(pz);
 
-        r = mmap_cache_get(m, x, PROT_READ, 0, false, 1, 2, NULL, &p, NULL);
+        r = mmap_cache_get(m, x, PROT_READ, 0, false, 1, 2, NULL, &p);
         assert_se(r >= 0);
 
-        r = mmap_cache_get(m, x, PROT_READ, 0, false, 2, 2, NULL, &q, NULL);
+        r = mmap_cache_get(m, x, PROT_READ, 0, false, 2, 2, NULL, &q);
         assert_se(r >= 0);
 
         assert_se((uint8_t*) p + 1 == (uint8_t*) q);
 
-        r = mmap_cache_get(m, x, PROT_READ, 1, false, 3, 2, NULL, &q, NULL);
+        r = mmap_cache_get(m, x, PROT_READ, 1, false, 3, 2, NULL, &q);
         assert_se(r >= 0);
 
         assert_se((uint8_t*) p + 2 == (uint8_t*) q);
 
-        r = mmap_cache_get(m, x, PROT_READ, 0, false, 16ULL*1024ULL*1024ULL, 2, NULL, &p, NULL);
+        r = mmap_cache_get(m, x, PROT_READ, 0, false, 16ULL*1024ULL*1024ULL, 2, NULL, &p);
         assert_se(r >= 0);
 
-        r = mmap_cache_get(m, x, PROT_READ, 1, false, 16ULL*1024ULL*1024ULL+1, 2, NULL, &q, NULL);
+        r = mmap_cache_get(m, x, PROT_READ, 1, false, 16ULL*1024ULL*1024ULL+1, 2, NULL, &q);
         assert_se(r >= 0);
 
         assert_se((uint8_t*) p + 1 == (uint8_t*) q);