journal: automatically deduce journal metrics from file system sizes

3 files changed, 148 insertions, 42 deletions

diff --git a/src/journal/journal-file.c b/src/journal/journal-file.c
index 190bfb996b..fd2e9ebbbc 100644
--- a/src/journal/journal-file.c
+++ b/src/journal/journal-file.c
@@ -39,6 +39,25 @@
 
 #define COMPRESSION_SIZE_THRESHOLD (64ULL)
 
+/* This is the minimum journal file size */
+#define JOURNAL_FILE_SIZE_MIN (64ULL*1024ULL)
+
+/* These are the lower and upper bounds if we deduce the max_use value
+ * from the file system size */
+#define DEFAULT_MAX_USE_LOWER (1ULL*1024ULL*1024ULL)           /* 1 MiB */
+#define DEFAULT_MAX_USE_UPPER (4ULL*1024ULL*1024ULL*1024ULL)   /* 4 GiB */
+
+/* This is the upper bound if we deduce max_size from max_use */
+#define DEFAULT_MAX_SIZE_UPPER (16ULL*1024ULL*1024ULL)         /* 16 MiB */
+
+/* This is the upper bound if we deduce the keep_free value from the
+ * file system size */
+#define DEFAULT_KEEP_FREE_UPPER (4ULL*1024ULL*1024ULL*1024ULL) /* 4 GiB */
+
+/* This is the keep_free value when we can't determine the system
+ * size */
+#define DEFAULT_KEEP_FREE (1024ULL*1024ULL)                    /* 1 MB */
+
 static const char signature[] = { 'L', 'P', 'K', 'S', 'H', 'H', 'R', 'H' };
 
 #define ALIGN64(x) (((x) + 7ULL) & ~7ULL)
@@ -1701,10 +1720,6 @@ int journal_file_open(
         f->writable = (flags & O_ACCMODE) != O_RDONLY;
         f->prot = prot_from_flags(flags);
 
-        f->metrics.max_size = DEFAULT_MAX_SIZE;
-        f->metrics.min_size = DEFAULT_MIN_SIZE;
-        f->metrics.keep_free = DEFAULT_KEEP_FREE;
-
         f->path = strdup(fname);
         if (!f->path) {
                 r = -ENOMEM;
@@ -1877,7 +1892,7 @@ int journal_directory_vacuum(const char *directory, uint64_t max_use, uint64_t m
         assert(directory);
 
         if (max_use <= 0)
-                max_use = DEFAULT_MAX_USE;
+                return 0;
 
         d = opendir(directory);
         if (!d)
@@ -2076,3 +2091,78 @@ int journal_file_copy_entry(JournalFile *from, JournalFile *to, Object *o, uint6
 
         return journal_file_append_entry_internal(to, &ts, xor_hash, items, n, seqnum, ret, offset);
 }
+
+void journal_default_metrics(JournalMetrics *m, int fd) {
+        uint64_t fs_size = 0;
+        struct statvfs ss;
+        char a[64], b[64], c[64], d[64];
+
+        assert(m);
+        assert(fd >= 0);
+
+        if (fstatvfs(fd, &ss) >= 0)
+                fs_size = ss.f_frsize * ss.f_blocks;
+
+        if (m->max_use == (uint64_t) -1) {
+
+                if (fs_size > 0) {
+                        m->max_use = PAGE_ALIGN(fs_size / 10); /* 10% of file system size */
+
+                        if (m->max_use > DEFAULT_MAX_USE_UPPER)
+                                m->max_use = DEFAULT_MAX_USE_UPPER;
+
+                        if (m->max_use < DEFAULT_MAX_USE_LOWER)
+                                m->max_use = DEFAULT_MAX_USE_LOWER;
+                } else
+                        m->max_use = DEFAULT_MAX_USE_LOWER;
+        } else {
+                m->max_use = PAGE_ALIGN(m->max_use);
+
+                if (m->max_use < JOURNAL_FILE_SIZE_MIN*2)
+                        m->max_use = JOURNAL_FILE_SIZE_MIN*2;
+        }
+
+        if (m->max_size == (uint64_t) -1) {
+                m->max_size = PAGE_ALIGN(m->max_use / 8); /* 8 chunks */
+
+                if (m->max_size > DEFAULT_MAX_SIZE_UPPER)
+                        m->max_size = DEFAULT_MAX_SIZE_UPPER;
+        } else
+                m->max_size = PAGE_ALIGN(m->max_size);
+
+        if (m->max_size < JOURNAL_FILE_SIZE_MIN)
+                m->max_size = JOURNAL_FILE_SIZE_MIN;
+
+        if (m->max_size*2 > m->max_use)
+                m->max_use = m->max_size*2;
+
+        if (m->min_size == (uint64_t) -1)
+                m->min_size = JOURNAL_FILE_SIZE_MIN;
+        else {
+                m->min_size = PAGE_ALIGN(m->min_size);
+
+                if (m->min_size < JOURNAL_FILE_SIZE_MIN)
+                        m->min_size = JOURNAL_FILE_SIZE_MIN;
+
+                if (m->min_size > m->max_size)
+                        m->max_size = m->min_size;
+        }
+
+        if (m->keep_free == (uint64_t) -1) {
+
+                if (fs_size > 0) {
+                        m->keep_free = PAGE_ALIGN(fs_size / 20); /* 5% of file system size */
+
+                        if (m->keep_free > DEFAULT_KEEP_FREE_UPPER)
+                                m->keep_free = DEFAULT_KEEP_FREE_UPPER;
+
+                } else
+                        m->keep_free = DEFAULT_KEEP_FREE;
+        }
+
+        log_debug("Fixed max_use=%s max_size=%s min_size=%s keep_free=%s",
+                  format_bytes(a, sizeof(a), m->max_use),
+                  format_bytes(b, sizeof(b), m->max_size),
+                  format_bytes(c, sizeof(c), m->min_size),
+                  format_bytes(d, sizeof(d), m->keep_free));
+}
diff --git a/src/journal/journal-file.h b/src/journal/journal-file.h
index acc55272a0..51d7119d09 100644
--- a/src/journal/journal-file.h
+++ b/src/journal/journal-file.h
@@ -28,11 +28,6 @@
 #include "util.h"
 #include "sd-id128.h"
 
-#define DEFAULT_MAX_SIZE (128ULL*1024ULL*1024ULL)
-#define DEFAULT_MIN_SIZE (256ULL*1024ULL)
-#define DEFAULT_KEEP_FREE (1ULL*1024ULL*1024ULL)
-#define DEFAULT_MAX_USE (16ULL*1024ULL*1024ULL*16ULL)
-
 typedef struct Window {
         void *ptr;
         uint64_t offset;
@@ -51,10 +46,10 @@ enum {
 };
 
 typedef struct JournalMetrics {
+        uint64_t max_use;
         uint64_t max_size;
         uint64_t min_size;
         uint64_t keep_free;
-        uint64_t max_use;
 } JournalMetrics;
 
 typedef struct JournalFile {
@@ -124,4 +119,6 @@ int journal_directory_vacuum(const char *directory, uint64_t max_use, uint64_t m
 
 void journal_file_post_change(JournalFile *f);
 
+void journal_default_metrics(JournalMetrics *m, int fd);
+
 #endif
diff --git a/src/journal/journald.c b/src/journal/journald.c
index 78ccb4e05a..f637d9471d 100644
--- a/src/journal/journald.c
+++ b/src/journal/journald.c
@@ -75,7 +75,9 @@ typedef struct Server {
 
         JournalRateLimit *rate_limit;
 
-        JournalMetrics metrics;
+        JournalMetrics runtime_metrics;
+        JournalMetrics system_metrics;
+
         bool compress;
 
         uint64_t cached_available_space;
@@ -117,15 +119,17 @@ struct StdoutStream {
 static int server_flush_to_var(Server *s);
 
 static uint64_t available_space(Server *s) {
-        char ids[33];
-        sd_id128_t machine;
-        char *p;
+        char ids[33], *p;
         const char *f;
+        sd_id128_t machine;
         struct statvfs ss;
         uint64_t sum = 0, avail = 0, ss_avail = 0;
         int r;
         DIR *d;
-        usec_t ts = now(CLOCK_MONOTONIC);
+        usec_t ts;
+        JournalMetrics *m;
+
+        ts = now(CLOCK_MONOTONIC);
 
         if (s->cached_available_space_timestamp + RECHECK_AVAILABLE_SPACE_USEC > ts)
                 return s->cached_available_space;
@@ -134,10 +138,15 @@ static uint64_t available_space(Server *s) {
         if (r < 0)
                 return 0;
 
-        if (s->system_journal)
+        if (s->system_journal) {
                 f = "/var/log/journal/";
-        else
+                m = &s->system_metrics;
+        } else {
                 f = "/run/log/journal/";
+                m = &s->runtime_metrics;
+        }
+
+        assert(m);
 
         p = strappend(f, sd_id128_to_string(machine, ids));
         if (!p)
@@ -175,11 +184,11 @@ static uint64_t available_space(Server *s) {
                 sum += (uint64_t) st.st_blocks * (uint64_t) st.st_blksize;
         }
 
-        avail = sum >= s->metrics.max_use ? 0 : s->metrics.max_use - sum;
+        avail = sum >= m->max_use ? 0 : m->max_use - sum;
 
         ss_avail = ss.f_bsize * ss.f_bavail;
 
-        ss_avail = ss_avail < s->metrics.keep_free ? 0 : ss_avail - s->metrics.keep_free;
+        ss_avail = ss_avail < m->keep_free ? 0 : ss_avail - m->keep_free;
 
         if (ss_avail < avail)
                 avail = ss_avail;
@@ -284,7 +293,7 @@ static JournalFile* find_journal(Server *s, uid_t uid) {
                 return s->system_journal;
 
         fix_perms(f, uid);
-        f->metrics = s->metrics;
+        f->metrics = s->system_metrics;
         f->compress = s->compress;
 
         r = hashmap_put(s->user_journals, UINT32_TO_PTR(uid), f);
@@ -335,25 +344,32 @@ static void server_vacuum(Server *s) {
                 return;
         }
 
-        if (asprintf(&p, "/var/log/journal/%s", sd_id128_to_string(machine, ids)) < 0) {
-                log_error("Out of memory.");
-                return;
-        }
+        sd_id128_to_string(machine, ids);
 
-        r = journal_directory_vacuum(p, s->metrics.max_use, s->metrics.keep_free);
-        if (r < 0 && r != -ENOENT)
-                log_error("Failed to vacuum %s: %s", p, strerror(-r));
-        free(p);
+        if (s->system_journal) {
+                if (asprintf(&p, "/var/log/journal/%s", ids) < 0) {
+                        log_error("Out of memory.");
+                        return;
+                }
 
-        if (asprintf(&p, "/run/log/journal/%s", ids) < 0) {
-                log_error("Out of memory.");
-                return;
+                r = journal_directory_vacuum(p, s->system_metrics.max_use, s->system_metrics.keep_free);
+                if (r < 0 && r != -ENOENT)
+                        log_error("Failed to vacuum %s: %s", p, strerror(-r));
+                free(p);
         }
 
-        r = journal_directory_vacuum(p, s->metrics.max_use, s->metrics.keep_free);
-        if (r < 0 && r != -ENOENT)
-                log_error("Failed to vacuum %s: %s", p, strerror(-r));
-        free(p);
+
+        if (s->runtime_journal) {
+                if (asprintf(&p, "/run/log/journal/%s", ids) < 0) {
+                        log_error("Out of memory.");
+                        return;
+                }
+
+                r = journal_directory_vacuum(p, s->runtime_metrics.max_use, s->runtime_metrics.keep_free);
+                if (r < 0 && r != -ENOENT)
+                        log_error("Failed to vacuum %s: %s", p, strerror(-r));
+                free(p);
+        }
 
         s->cached_available_space_timestamp = 0;
 }
@@ -1144,7 +1160,9 @@ static int system_journal_open(Server *s) {
                 free(fn);
 
                 if (r >= 0) {
-                        s->system_journal->metrics = s->metrics;
+                        journal_default_metrics(&s->system_metrics, s->system_journal->fd);
+
+                        s->system_journal->metrics = s->system_metrics;
                         s->system_journal->compress = s->compress;
 
                         fix_perms(s->system_journal, 0);
@@ -1200,7 +1218,9 @@ static int system_journal_open(Server *s) {
                 }
 
                 if (s->runtime_journal) {
-                        s->runtime_journal->metrics = s->metrics;
+                        journal_default_metrics(&s->runtime_metrics, s->runtime_journal->fd);
+
+                        s->runtime_journal->metrics = s->runtime_metrics;
                         s->runtime_journal->compress = s->compress;
 
                         fix_perms(s->runtime_journal, 0);
@@ -1717,12 +1737,11 @@ static int server_init(Server *s) {
 
         zero(*s);
         s->syslog_fd = s->native_fd = s->stdout_fd = s->signal_fd = s->epoll_fd = -1;
-        s->metrics.max_size = DEFAULT_MAX_SIZE;
-        s->metrics.min_size = DEFAULT_MIN_SIZE;
-        s->metrics.keep_free = DEFAULT_KEEP_FREE;
-        s->metrics.max_use = DEFAULT_MAX_USE;
         s->compress = true;
 
+        memset(&s->system_metrics, 0xFF, sizeof(s->system_metrics));
+        memset(&s->runtime_metrics, 0xFF, sizeof(s->runtime_metrics));
+
         s->user_journals = hashmap_new(trivial_hash_func, trivial_compare_func);
         if (!s->user_journals) {
                 log_error("Out of memory.");