From: Jérémie Galarneau Date: Sat, 23 Nov 2019 00:25:36 +0000 (-0500) Subject: fd-tracker: use lttng_inode to store fs_handle's path X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=commitdiff_plain;h=874a34411a7538cd7462cf4f763b172abd83b4b6 fd-tracker: use lttng_inode to store fs_handle's path Storing paths as part of the lttng_inode object, which may be shared by multiple fs_handles reduces the number of copies of the path. Signed-off-by: Jérémie Galarneau --- diff --git a/src/common/fd-tracker/fd-tracker.c b/src/common/fd-tracker/fd-tracker.c index a4f4bcba7..c8cbc6b33 100644 --- a/src/common/fd-tracker/fd-tracker.c +++ b/src/common/fd-tracker/fd-tracker.c @@ -33,6 +33,7 @@ #include "common/hashtable/hashtable.h" #include "fd-tracker.h" +#include "inode.h" /* Tracker lock must be taken by the user. */ #define TRACKED_COUNT(tracker) \ @@ -84,10 +85,10 @@ struct fd_tracker { struct cds_list_head active_handles; struct cds_list_head suspended_handles; struct cds_lfht *unsuspendable_fds; + struct lttng_inode_registry *inode_registry; }; struct open_properties { - char *path; int flags; struct { bool is_set; @@ -112,6 +113,7 @@ struct fs_handle { */ struct fd_tracker *tracker; struct open_properties properties; + struct lttng_inode *inode; int fd; /* inode number of the file at the time of the handle's creation. */ uint64_t ino; @@ -144,7 +146,8 @@ static int match_fd(struct cds_lfht_node *node, const void *key); static void unsuspendable_fd_destroy(struct unsuspendable_fd *entry); static struct unsuspendable_fd *unsuspendable_fd_create(const char *name, int fd); -static int open_from_properties(struct open_properties *properties); +static int open_from_properties(const char *path, + struct open_properties *properties); static void fs_handle_log(struct fs_handle *handle); static int fs_handle_suspend(struct fs_handle *handle); @@ -215,25 +218,32 @@ error: static void fs_handle_log(struct fs_handle *handle) { + const char *path; + pthread_mutex_lock(&handle->lock); + path = lttng_inode_get_path(handle->inode); + if (handle->fd >= 0) { DBG_NO_LOC(" %s [active, fd %d%s]", - handle->properties.path, + path, handle->fd, handle->in_use ? ", in use" : ""); } else { - DBG_NO_LOC(" %s [suspended]", handle->properties.path); + DBG_NO_LOC(" %s [suspended]", path); } pthread_mutex_unlock(&handle->lock); } +/* Tracker lock must be held by the caller. */ static int fs_handle_suspend(struct fs_handle *handle) { int ret = 0; struct stat fs_stat; + const char *path; pthread_mutex_lock(&handle->lock); + path = lttng_inode_get_path(handle->inode); assert(handle->fd >= 0); if (handle->in_use) { /* This handle can't be suspended as it is currently in use. */ @@ -241,10 +251,10 @@ int fs_handle_suspend(struct fs_handle *handle) goto end; } - ret = stat(handle->properties.path, &fs_stat); + ret = stat(path, &fs_stat); if (ret) { PERROR("Filesystem handle to %s cannot be suspended as stat() failed", - handle->properties.path); + path); ret = -errno; goto end; } @@ -252,7 +262,7 @@ int fs_handle_suspend(struct fs_handle *handle) if (fs_stat.st_ino != handle->ino) { /* Don't suspend as the handle would not be restorable. */ WARN("Filesystem handle to %s cannot be suspended as its inode changed", - handle->properties.path); + path); ret = -ENOENT; goto end; } @@ -260,7 +270,7 @@ int fs_handle_suspend(struct fs_handle *handle) handle->offset = lseek(handle->fd, 0, SEEK_CUR); if (handle->offset == -1) { WARN("Filesystem handle to %s cannot be suspended as lseek() failed to sample its current position", - handle->properties.path); + path); ret = -errno; goto end; } @@ -268,12 +278,12 @@ int fs_handle_suspend(struct fs_handle *handle) ret = close(handle->fd); if (ret) { PERROR("Filesystem handle to %s cannot be suspended as close() failed", - handle->properties.path); + path); ret = -errno; goto end; } DBG("Suspended filesystem handle to %s (fd %i) at position %" PRId64, - handle->properties.path, handle->fd, handle->offset); + path, handle->fd, handle->offset); handle->fd = -1; end: if (ret) { @@ -288,12 +298,15 @@ static int fs_handle_restore(struct fs_handle *handle) { int ret, fd = -1; + const char *path = lttng_inode_get_path(handle->inode); assert(handle->fd == -1); - ret = open_from_properties(&handle->properties); + assert(path); + ret = open_from_properties(path, + &handle->properties); if (ret < 0) { PERROR("Failed to restore filesystem handle to %s, open() failed", - handle->properties.path); + path); ret = -errno; goto end; } @@ -302,12 +315,12 @@ int fs_handle_restore(struct fs_handle *handle) ret = lseek(fd, handle->offset, SEEK_SET); if (ret < 0) { PERROR("Failed to restore filesystem handle to %s, lseek() failed", - handle->properties.path); + path); ret = -errno; goto end; } DBG("Restored filesystem handle to %s (fd %i) at position %" PRId64, - handle->properties.path, fd, handle->offset); + path, fd, handle->offset); ret = 0; handle->fd = fd; fd = -1; @@ -319,7 +332,7 @@ end: } static -int open_from_properties(struct open_properties *properties) +int open_from_properties(const char *path, struct open_properties *properties) { int ret; @@ -330,10 +343,10 @@ int open_from_properties(struct open_properties *properties) * thus it is ignored here. */ if ((properties->flags & O_CREAT) && properties->mode.is_set) { - ret = open(properties->path, properties->flags, + ret = open(path, properties->flags, properties->mode.value); } else { - ret = open(properties->path, properties->flags); + ret = open(path, properties->flags); } /* * Some flags should not be used beyond the initial open() of a @@ -374,10 +387,22 @@ struct fd_tracker *fd_tracker_create(unsigned int capacity) tracker->capacity = capacity; tracker->unsuspendable_fds = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); + if (!tracker->unsuspendable_fds) { + ERR("Failed to create fd-tracker's unsuspendable_fds hash table"); + goto error; + } + tracker->inode_registry = lttng_inode_registry_create(); + if (!tracker->inode_registry) { + ERR("Failed to create fd-tracker's inode registry"); + goto error; + } DBG("File descriptor tracker created with a limit of %u simultaneously-opened FDs", capacity); end: return tracker; +error: + fd_tracker_destroy(tracker); + return NULL; } void fd_tracker_log(struct fd_tracker *tracker) @@ -446,8 +471,10 @@ int fd_tracker_destroy(struct fd_tracker *tracker) } pthread_mutex_unlock(&tracker->lock); - ret = cds_lfht_destroy(tracker->unsuspendable_fds, NULL); - assert(!ret); + if (tracker->unsuspendable_fds) { + ret = cds_lfht_destroy(tracker->unsuspendable_fds, NULL); + assert(!ret); + } pthread_mutex_destroy(&tracker->lock); free(tracker); end: @@ -461,16 +488,11 @@ struct fs_handle *fd_tracker_open_fs_handle(struct fd_tracker *tracker, struct fs_handle *handle = NULL; struct stat fd_stat; struct open_properties properties = { - .path = strdup(path), .flags = flags, .mode.is_set = !!mode, .mode.value = mode ? *mode : 0, }; - if (!properties.path) { - goto end; - } - pthread_mutex_lock(&tracker->lock); if (ACTIVE_COUNT(tracker) == tracker->capacity) { if (tracker->count.suspendable.active > 0) { @@ -503,7 +525,7 @@ struct fs_handle *fd_tracker_open_fs_handle(struct fd_tracker *tracker, goto end; } - handle->fd = open_from_properties(&properties); + handle->fd = open_from_properties(path, &properties); if (handle->fd < 0) { PERROR("Failed to open fs handle to %s, open() returned", path); ret = -errno; @@ -511,7 +533,14 @@ struct fs_handle *fd_tracker_open_fs_handle(struct fd_tracker *tracker, } handle->properties = properties; - properties.path = NULL; + + handle->inode = lttng_inode_registry_get_inode(tracker->inode_registry, + handle->fd, path); + if (!handle->inode) { + ERR("Failed to get lttng_inode corresponding to file %s", + path); + goto error_destroy; + } if (fstat(handle->fd, &fd_stat)) { PERROR("Failed to retrieve file descriptor inode while creating fs handle, fstat() returned"); @@ -524,7 +553,6 @@ struct fs_handle *fd_tracker_open_fs_handle(struct fd_tracker *tracker, handle->tracker = tracker; pthread_mutex_unlock(&tracker->lock); end: - free(properties.path); return handle; error_destroy: pthread_mutex_unlock(&tracker->lock); @@ -816,6 +844,7 @@ int fs_handle_unlink(struct fs_handle *handle) int fs_handle_close(struct fs_handle *handle) { int ret = 0; + const char *path; if (!handle) { ret = -EINVAL; @@ -824,6 +853,7 @@ int fs_handle_close(struct fs_handle *handle) pthread_mutex_lock(&handle->tracker->lock); pthread_mutex_lock(&handle->lock); + path = lttng_inode_get_path(handle->inode); fd_tracker_untrack(handle->tracker, handle); if (handle->fd >= 0) { /* @@ -832,14 +862,14 @@ int fs_handle_close(struct fs_handle *handle) */ if (close(handle->fd)) { PERROR("Failed to close the file descritptor (%d) of fs handle to %s, close() returned", - handle->fd, handle->properties.path); + handle->fd, path); } handle->fd = -1; } + lttng_inode_put(handle->inode); pthread_mutex_unlock(&handle->lock); pthread_mutex_destroy(&handle->lock); pthread_mutex_unlock(&handle->tracker->lock); - free(handle->properties.path); free(handle); end: return ret;