From 5f25c0ff7f794828bfc05a54957ccdd9843dd1d9 Mon Sep 17 00:00:00 2001 From: Jan Janssen Date: Sat, 6 Sep 2014 10:14:41 +0200 Subject: [PATCH 1/2] journal: Fix sd_journal_enumerate_unique skipping values 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 f25cda6..038b437 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 6b4bf0d..fa5b943 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 b4e8f73..f74adcb 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 2d268fc..b7db6f1 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; outofmem: @@ -537,7 +546,8 @@ int mmap_cache_get( uint64_t offset, size_t size, struct stat *st, - void **ret) { + void **ret, + void **release_cookie) { int r; @@ -547,14 +557,14 @@ 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; @@ -563,16 +573,13 @@ 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; @@ -580,7 +587,6 @@ 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) @@ -589,7 +595,7 @@ 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 1fc9f01..523f604 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); -- 2.1.2