[systemd-devel] [PATCH] journal: Fix sd_journal_enumerate_unique skipping values
Zbigniew Jędrzejewski-Szmek
zbyszek at in.waw.pl
Mon Oct 6 09:57:38 PDT 2014
On Mon, Oct 06, 2014 at 06:36:34PM +0200, Jan Janssen wrote:
> *bump*
Sorry, I'll look into this.
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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