From d9c7a87b35289e9a5ba94c097e861640d1357e6d Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Tue, 28 Sep 2010 21:46:14 +0200 Subject: [PATCH] readahead: ignore replay events when collecting --- src/readahead-collect.c | 58 ++++++++++++++++++++++++++--------------- src/readahead-common.c | 30 +++++++++++++++++++++ src/readahead-common.h | 10 +++++++ src/readahead-replay.c | 8 ++++++ 4 files changed, 85 insertions(+), 21 deletions(-) diff --git a/src/readahead-collect.c b/src/readahead-collect.c index 0838dd39..5c09f7a9 100644 --- a/src/readahead-collect.c +++ b/src/readahead-collect.c @@ -64,6 +64,8 @@ static unsigned arg_files_max = 16*1024; static off_t arg_file_size_max = READAHEAD_FILE_SIZE_MAX; static usec_t arg_timeout = 2*USEC_PER_MINUTE; +static ReadaheadShared *shared = NULL; + /* Avoid collisions with the NULL pointer */ #define SECTOR_TO_PTR(s) ULONG_TO_PTR((s)+1) #define PTR_TO_SECTOR(p) (PTR_TO_ULONG(p)-1) @@ -379,36 +381,44 @@ static int collect(const char *root) { } for (m = &data.metadata; FAN_EVENT_OK(m, n); m = FAN_EVENT_NEXT(m, n)) { + char fn[PATH_MAX]; + int k; - if (m->pid != my_pid && m->fd >= 0) { - char fn[PATH_MAX]; - int k; + if (m->fd < 0) + goto next_iteration; - snprintf(fn, sizeof(fn), "/proc/self/fd/%i", m->fd); - char_array_0(fn); + if (m->pid == my_pid) + goto next_iteration; - if ((k = readlink_malloc(fn, &p)) >= 0) { + __sync_synchronize(); + if (m->pid == shared->replay) + goto next_iteration; - if (startswith(p, "/tmp") || - hashmap_get(files, p)) - /* Not interesting, or - * already read */ - free(p); - else { - unsigned long ul; + snprintf(fn, sizeof(fn), "/proc/self/fd/%i", m->fd); + char_array_0(fn); + + if ((k = readlink_malloc(fn, &p)) >= 0) { - ul = fd_first_block(m->fd); + if (startswith(p, "/tmp") || + hashmap_get(files, p)) + /* Not interesting, or + * already read */ + free(p); + else { + unsigned long ul; - if ((k = hashmap_put(files, p, SECTOR_TO_PTR(ul))) < 0) { - log_warning("set_put() failed: %s", strerror(-k)); - free(p); - } + ul = fd_first_block(m->fd); + + if ((k = hashmap_put(files, p, SECTOR_TO_PTR(ul))) < 0) { + log_warning("set_put() failed: %s", strerror(-k)); + free(p); } + } - } else - log_warning("readlink(%s) failed: %s", fn, strerror(-k)); - } + } else + log_warning("readlink(%s) failed: %s", fn, strerror(-k)); + next_iteration: if (m->fd) close_nointr_nofail(m->fd); } @@ -635,6 +645,12 @@ int main(int argc, char *argv[]) { return 0; } + if (!(shared = shared_get())) + return 1; + + shared->collect = getpid(); + __sync_synchronize(); + if (collect(optind < argc ? argv[optind] : "/") < 0) return 1; diff --git a/src/readahead-common.c b/src/readahead-common.c index a2f6f173..e01ae607 100644 --- a/src/readahead-common.c +++ b/src/readahead-common.c @@ -25,6 +25,9 @@ #include #include #include +#include +#include +#include #include "log.h" #include "readahead-common.h" @@ -137,3 +140,30 @@ int open_inotify(void) { return fd; } + +ReadaheadShared *shared_get(void) { + int fd; + ReadaheadShared *m = NULL; + + if ((fd = open("/dev/.systemd/readahead/shared", O_CREAT|O_RDWR|O_CLOEXEC, 0644)) < 0) { + log_error("Failed to create shared memory segment: %m"); + goto finish; + } + + if (ftruncate(fd, sizeof(ReadaheadShared)) < 0) { + log_error("Failed to truncate shared memory segment: %m"); + goto finish; + } + + if ((m = mmap(NULL, sizeof(ReadaheadShared), PROT_WRITE|PROT_READ, MAP_SHARED, fd, 0)) == MAP_FAILED) { + log_error("Failed to mmap shared memory segment: %m"); + m = NULL; + goto finish; + } + +finish: + if (fd >= 0) + close_nointr_nofail(fd); + + return m; +} diff --git a/src/readahead-common.h b/src/readahead-common.h index 3f64f290..7add6261 100644 --- a/src/readahead-common.h +++ b/src/readahead-common.h @@ -23,6 +23,9 @@ ***/ #include +#include + +#include "macro.h" #define READAHEAD_FILE_SIZE_MAX (128*1024*1024) @@ -34,4 +37,11 @@ bool enough_ram(void); int open_inotify(void); +typedef struct ReadaheadShared { + pid_t collect; + pid_t replay; +} _packed_ ReadaheadShared; + +ReadaheadShared *shared_get(void); + #endif diff --git a/src/readahead-replay.c b/src/readahead-replay.c index f0710e5d..e22fc043 100644 --- a/src/readahead-replay.c +++ b/src/readahead-replay.c @@ -44,6 +44,8 @@ static off_t arg_file_size_max = READAHEAD_FILE_SIZE_MAX; +static ReadaheadShared *shared = NULL; + static int unpack_file(FILE *pack) { char fn[PATH_MAX]; int r = 0, fd = -1; @@ -338,6 +340,12 @@ int main(int argc, char*argv[]) { return 0; } + if (!(shared = shared_get())) + return 1; + + shared->replay = getpid(); + __sync_synchronize(); + if (replay(optind < argc ? argv[optind] : "/") < 0) return 1; -- 2.39.5