[systemd-devel] [PATCH] journal: Fix sd_journal_enumerate_unique skipping values
Zbigniew Jędrzejewski-Szmek
zbyszek at in.waw.pl
Tue Oct 7 16:40:35 PDT 2014
On Mon, Oct 06, 2014 at 06:57:38PM +0200, Zbigniew Jędrzejewski-Szmek wrote:
> On Mon, Oct 06, 2014 at 06:36:34PM +0200, Jan Janssen wrote:
> > *bump*
> Sorry, I'll look into this.
Doesn't work. Both without or with your other patch
sd_journal_enumerate_unique I get bogus results on my test case. It
seems the issue is more complicated.
Zbyszek
> > On 2014-09-06 10:36, Jan Janssen wrote:
> > >sd_journal_enumerate_unique will lock its mmap window to prevent it
> > >from being released by calling mmap_cache_get with keep_always=true.
> > >This call may return windows that are wider, but compatible with the
> > >parameters provided to it.
> > >
> > >This can result in a mismatch where the window to be released cannot
> > >properly be selected, because we have more than one window matching the
> > >parameters of mmap_cache_release. Therefore, introduce a release_cookie
> > >to be used when releasing the window.
> > >
> > >https://bugs.freedesktop.org/show_bug.cgi?id=79380
> > >---
> > > src/journal/journal-file.c | 2 +-
> > > src/journal/journal-file.h | 11 ++++-------
> > > src/journal/journal-verify.c | 2 +-
> > > src/journal/mmap-cache.c | 32 +++++++++++++++++++-------------
> > > src/journal/mmap-cache.h | 8 +++-----
> > > src/journal/sd-journal.c | 11 ++++++-----
> > > src/journal/test-mmap-cache.c | 10 +++++-----
> > > 7 files changed, 39 insertions(+), 37 deletions(-)
> > >
> > >diff --git a/src/journal/journal-file.c b/src/journal/journal-file.c
> > >index 7286e14..0ed51ed 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);
> > >+ return mmap_cache_get(f->mmap, f->fd, f->prot, context, keep_always, offset, size, &f->last_stat, ret, NULL);
> > > }
> > >
> > > static uint64_t minimum_header_size(Object *o) {
> > >diff --git a/src/journal/journal-file.h b/src/journal/journal-file.h
> > >index da2ef3b..da1b793 100644
> > >--- a/src/journal/journal-file.h
> > >+++ b/src/journal/journal-file.h
> > >@@ -212,17 +212,14 @@ static unsigned type_to_context(int type) {
> > > return type > 0 && type < _OBJECT_TYPE_MAX ? type : 0;
> > > }
> > >
> > >-static inline int journal_file_object_keep(JournalFile *f, Object *o, uint64_t offset) {
> > >+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);
> > >+ offset, s, &f->last_stat, NULL, release_cookie);
> > > }
> > >
> > >-static inline int journal_file_object_release(JournalFile *f, Object *o, uint64_t offset) {
> > >- unsigned context = type_to_context(o->object.type);
> > >- uint64_t s = le64toh(o->object.size);
> > >-
> > >- return mmap_cache_release(f->mmap, f->fd, f->prot, context, offset, s);
> > >+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 6c8ca8c..a1c34ac 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);
> > >+ r = mmap_cache_get(m, fd, PROT_READ|PROT_WRITE, 0, false, c * sizeof(uint64_t), sizeof(uint64_t), NULL, (void **) &z, NULL);
> > > if (r < 0)
> > > return r;
> > >
> > >diff --git a/src/journal/mmap-cache.c b/src/journal/mmap-cache.c
> > >index 7dbbb5e..64bc8da 100644
> > >--- a/src/journal/mmap-cache.c
> > >+++ b/src/journal/mmap-cache.c
> > >@@ -352,7 +352,8 @@ static int try_context(
> > > bool keep_always,
> > > uint64_t offset,
> > > size_t size,
> > >- void **ret) {
> > >+ void **ret,
> > >+ void **release_cookie) {
> > >
> > > Context *c;
> > >
> > >@@ -381,6 +382,8 @@ static int try_context(
> > >
> > > if (ret)
> > > *ret = (uint8_t*) c->window->ptr + (offset - c->window->offset);
> > >+ if (keep_always && release_cookie)
> > >+ *release_cookie = c->window;
> > > return 1;
> > > }
> > >
> > >@@ -392,7 +395,8 @@ static int find_mmap(
> > > bool keep_always,
> > > uint64_t offset,
> > > size_t size,
> > >- void **ret) {
> > >+ void **ret,
> > >+ void **release_cookie) {
> > >
> > > FileDescriptor *f;
> > > Window *w;
> > >@@ -425,6 +429,8 @@ static int find_mmap(
> > >
> > > if (ret)
> > > *ret = (uint8_t*) w->ptr + (offset - w->offset);
> > >+ if (keep_always && release_cookie)
> > >+ *release_cookie = c->window;
> > > return 1;
> > > }
> > >
> > >@@ -437,7 +443,8 @@ static int add_mmap(
> > > uint64_t offset,
> > > size_t size,
> > > struct stat *st,
> > >- void **ret) {
> > >+ void **ret,
> > >+ void **release_cookie) {
> > >
> > > uint64_t woffset, wsize;
> > > Context *c;
> > >@@ -521,6 +528,8 @@ static int add_mmap(
> > >
> > > if (ret)
> > > *ret = (uint8_t*) w->ptr + (offset - w->offset);
> > >+ if (keep_always && release_cookie)
> > >+ *release_cookie = c->window;
> > > return 1;
> > > }
> > >
> > >@@ -533,7 +542,8 @@ int mmap_cache_get(
> > > uint64_t offset,
> > > size_t size,
> > > struct stat *st,
> > >- void **ret) {
> > >+ void **ret,
> > >+ void **release_cookie) {
> > >
> > > int r;
> > >
> > >@@ -543,14 +553,14 @@ int mmap_cache_get(
> > > assert(size > 0);
> > >
> > > /* Check whether the current context is the right one already */
> > >- r = try_context(m, fd, prot, context, keep_always, offset, size, ret);
> > >+ r = try_context(m, fd, prot, context, keep_always, offset, size, ret, release_cookie);
> > > 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);
> > >+ r = find_mmap(m, fd, prot, context, keep_always, offset, size, ret, release_cookie);
> > > if (r != 0) {
> > > m->n_hit ++;
> > > return r;
> > >@@ -559,16 +569,13 @@ int mmap_cache_get(
> > > m->n_missed++;
> > >
> > > /* Create a new mmap */
> > >- return add_mmap(m, fd, prot, context, keep_always, offset, size, st, ret);
> > >+ return add_mmap(m, fd, prot, context, keep_always, offset, size, st, ret, release_cookie);
> > > }
> > >
> > > int mmap_cache_release(
> > > MMapCache *m,
> > > int fd,
> > >- int prot,
> > >- unsigned context,
> > >- uint64_t offset,
> > >- size_t size) {
> > >+ void *release_cookie) {
> > >
> > > FileDescriptor *f;
> > > Window *w;
> > >@@ -576,7 +583,6 @@ int mmap_cache_release(
> > > assert(m);
> > > assert(m->n_ref > 0);
> > > assert(fd >= 0);
> > >- assert(size > 0);
> > >
> > > f = hashmap_get(m->fds, INT_TO_PTR(fd + 1));
> > > if (!f)
> > >@@ -585,7 +591,7 @@ int mmap_cache_release(
> > > assert(f->fd == fd);
> > >
> > > LIST_FOREACH(by_fd, w, f->windows)
> > >- if (window_matches(w, fd, prot, offset, size))
> > >+ if (w == release_cookie)
> > > break;
> > >
> > > if (!w)
> > >diff --git a/src/journal/mmap-cache.h b/src/journal/mmap-cache.h
> > >index 647555a..76e5316 100644
> > >--- a/src/journal/mmap-cache.h
> > >+++ b/src/journal/mmap-cache.h
> > >@@ -40,14 +40,12 @@ int mmap_cache_get(
> > > uint64_t offset,
> > > size_t size,
> > > struct stat *st,
> > >- void **ret);
> > >+ void **ret,
> > >+ void **release_cookie);
> > > int mmap_cache_release(
> > > MMapCache *m,
> > > int fd,
> > >- int prot,
> > >- unsigned context,
> > >- uint64_t offset,
> > >- size_t size);
> > >+ void *release_cookie);
> > > 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 693707c..edb60bb 100644
> > >--- a/src/journal/sd-journal.c
> > >+++ b/src/journal/sd-journal.c
> > >@@ -2520,6 +2520,7 @@ _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) {
> > >@@ -2563,7 +2564,7 @@ _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);
> > >+ r = journal_file_object_keep(j->unique_file, o, j->unique_offset, &release_cookie);
> > > if (r < 0)
> > > return r;
> > >
> > >@@ -2611,13 +2612,13 @@ _public_ int sd_journal_enumerate_unique(sd_journal *j, const void **data, size_
> > > found = true;
> > > }
> > >
> > >- if (found)
> > >- continue;
> > >-
> > >- r = journal_file_object_release(j->unique_file, o, j->unique_offset);
> > >+ r = journal_file_object_release(j->unique_file, release_cookie);
> > > if (r < 0)
> > > return r;
> > >
> > >+ if (found)
> > >+ continue;
> > >+
> > > r = return_data(j, j->unique_file, o, data, l);
> > > if (r < 0)
> > > return r;
> > >diff --git a/src/journal/test-mmap-cache.c b/src/journal/test-mmap-cache.c
> > >index b7bb260..778e884 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(z >= 0);
> > > unlink(pz);
> > >
> > >- r = mmap_cache_get(m, x, PROT_READ, 0, false, 1, 2, NULL, &p);
> > >+ r = mmap_cache_get(m, x, PROT_READ, 0, false, 1, 2, NULL, &p, NULL);
> > > assert(r >= 0);
> > >
> > >- r = mmap_cache_get(m, x, PROT_READ, 0, false, 2, 2, NULL, &q);
> > >+ r = mmap_cache_get(m, x, PROT_READ, 0, false, 2, 2, NULL, &q, NULL);
> > > assert(r >= 0);
> > >
> > > assert((uint8_t*) p + 1 == (uint8_t*) q);
> > >
> > >- r = mmap_cache_get(m, x, PROT_READ, 1, false, 3, 2, NULL, &q);
> > >+ r = mmap_cache_get(m, x, PROT_READ, 1, false, 3, 2, NULL, &q, NULL);
> > > assert(r >= 0);
> > >
> > > assert((uint8_t*) p + 2 == (uint8_t*) q);
> > >
> > >- r = mmap_cache_get(m, x, PROT_READ, 0, false, 16ULL*1024ULL*1024ULL, 2, NULL, &p);
> > >+ r = mmap_cache_get(m, x, PROT_READ, 0, false, 16ULL*1024ULL*1024ULL, 2, NULL, &p, NULL);
> > > assert(r >= 0);
> > >
> > >- r = mmap_cache_get(m, x, PROT_READ, 1, false, 16ULL*1024ULL*1024ULL+1, 2, NULL, &q);
> > >+ r = mmap_cache_get(m, x, PROT_READ, 1, false, 16ULL*1024ULL*1024ULL+1, 2, NULL, &q, NULL);
> > > assert(r >= 0);
> > >
> > > assert((uint8_t*) p + 1 == (uint8_t*) q);
> > >
> > _______________________________________________
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> > http://lists.freedesktop.org/mailman/listinfo/systemd-devel
> >
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