X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=ltt-debugfs-abi.c;h=f9f5bedf7913c37ccaf24e92fe6af8c5e674803f;hb=f3bc08c50e1b302bceea699027d889fd6d9af525;hp=9043759f960102c443196f4e9567680cd8371f05;hpb=d7847692f0942697df3f9f3597da8bc57911e61e;p=lttng-modules.git diff --git a/ltt-debugfs-abi.c b/ltt-debugfs-abi.c index 9043759f..f9f5bedf 100644 --- a/ltt-debugfs-abi.c +++ b/ltt-debugfs-abi.c @@ -28,7 +28,7 @@ #include #include #include -#include +#include "wrapper/ringbuffer/vfs.h" #include "ltt-debugfs-abi.h" #include "ltt-events.h" @@ -41,8 +41,15 @@ static struct dentry *lttng_dentry; static const struct file_operations lttng_fops; static const struct file_operations lttng_session_fops; static const struct file_operations lttng_channel_fops; +static const struct file_operations lttng_metadata_fops; static const struct file_operations lttng_event_fops; +enum channel_type { + PER_CPU_CHANNEL, + GLOBAL_CHANNEL, + METADATA_CHANNEL, +}; + static int lttng_abi_create_session(void) { @@ -107,10 +114,52 @@ static const struct file_operations lttng_fops = { #endif }; +/* + * We tolerate no failure in this function (if one happens, we print a dmesg + * error, but cannot return any error, because the channel information is + * invariant. + */ +static +void lttng_metadata_create_events(struct file *channel_file) +{ + struct ltt_channel *channel = channel_file->private_data; + char *event_name = "lttng-metadata"; + struct ltt_event *event; + int ret; + void *probe; + + probe = ltt_probe_get(event_name); + if (!probe) { + ret = -ENOENT; + goto probe_error; + } + /* + * We tolerate no failure path after event creation. It will stay + * invariant for the rest of the session. + */ + event = ltt_event_create(channel, event_name, INSTRUM_TRACEPOINTS, + probe, NULL); + if (!event) { + goto event_error; + ret = -EEXIST; + } + return; + +event_error: + ltt_probe_put(probe); +probe_error: + WARN_ON(1); + return; /* not allowed to return error */ +} + +static int lttng_abi_create_channel(struct file *session_file, - struct lttng_channel __user *uchan_param) + struct lttng_channel __user *uchan_param, + enum channel_type channel_type) { struct ltt_session *session = session_file->private_data; + const struct file_operations *fops; + const char *transport_name; struct ltt_channel *chan; struct file *chan_file; struct lttng_channel chan_param; @@ -131,11 +180,30 @@ int lttng_abi_create_channel(struct file *session_file, ret = PTR_ERR(chan_file); goto file_error; } + switch (channel_type) { + case PER_CPU_CHANNEL: + transport_name = chan_param.overwrite ? + "relay-overwrite" : "relay-discard"; + fops = <tng_channel_fops; + break; + case GLOBAL_CHANNEL: + transport_name = chan_param.overwrite ? + "global-relay-overwrite" : "global-relay-discard"; + fops = <tng_channel_fops; + break; + case METADATA_CHANNEL: + transport_name = "global-relay-discard"; + fops = <tng_metadata_fops; + break; + default: + transport_name = ""; + break; + } /* * We tolerate no failure path after channel creation. It will stay * invariant for the rest of the session. */ - chan = ltt_channel_create(session, chan_param.overwrite, NULL, + chan = ltt_channel_create(session, transport_name, NULL, chan_param.subbuf_size, chan_param.num_subbuf, chan_param.switch_timer_interval, @@ -147,6 +215,9 @@ int lttng_abi_create_channel(struct file *session_file, chan->file = chan_file; chan_file->private_data = chan; fd_install(chan_fd, chan_file); + if (channel_type == METADATA_CHANNEL) + lttng_metadata_create_events(chan_file); + /* The channel created holds a reference on the session */ atomic_long_inc(&session_file->f_count); @@ -180,11 +251,17 @@ long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg) switch (cmd) { case LTTNG_CHANNEL: - return lttng_abi_create_channel(file, (struct lttng_channel __user *)arg); + return lttng_abi_create_channel(file, + (struct lttng_channel __user *)arg, + PER_CPU_CHANNEL); case LTTNG_SESSION_START: return ltt_session_start(session); case LTTNG_SESSION_STOP: return ltt_session_stop(session); + case LTTNG_METADATA: + return lttng_abi_create_channel(file, + (struct lttng_channel __user *)arg, + METADATA_CHANNEL); default: return -ENOIOCTLCMD; } @@ -240,9 +317,18 @@ int lttng_abi_open_stream(struct file *channel_file) ret = PTR_ERR(stream_file); goto file_error; } + /* + * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor + * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this + * file descriptor, so we set FMODE_PREAD here. + */ + stream_file->f_mode |= FMODE_PREAD; fd_install(stream_fd, stream_file); - /* The stream holds a reference on the channel */ - atomic_long_inc(&channel_file->f_count); + /* + * The stream holds a reference to the channel within the generic ring + * buffer library, so no need to hold a refcount on the channel and + * session files here. + */ return stream_fd; file_error: @@ -262,6 +348,7 @@ int lttng_abi_create_event(struct file *channel_file, struct lttng_event event_param; int event_fd, ret; struct file *event_file; + void *probe; if (copy_from_user(&event_param, uevent_param, sizeof(event_param))) return -EFAULT; @@ -273,6 +360,12 @@ int lttng_abi_create_event(struct file *channel_file, goto name_error; } event_name[PATH_MAX - 1] = '\0'; + + probe = ltt_probe_get(event_name); + if (!probe) { + ret = -ENOENT; + goto probe_error; + } event_fd = get_unused_fd(); if (event_fd < 0) { ret = event_fd; @@ -290,7 +383,7 @@ int lttng_abi_create_event(struct file *channel_file, * invariant for the rest of the session. */ event = ltt_event_create(channel, event_name, event_param.itype, - (void *) 0x1, NULL); /* TODO connect real probe */ + probe, NULL); if (!event) { goto event_error; ret = -EEXIST; @@ -307,6 +400,8 @@ event_error: file_error: put_unused_fd(event_fd); fd_error: + ltt_probe_put(probe); +probe_error: name_error: kfree(event_name); return ret; @@ -326,7 +421,6 @@ name_error: * LTTNG_EVENT * Returns an event file descriptor or failure. * - * The returned session will be deleted when its file descriptor is closed. * Channel and event file descriptors also hold a reference on the session. */ static @@ -342,6 +436,30 @@ long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg) } } +/** + * lttng_metadata_ioctl - lttng syscall through ioctl + * + * @file: the file + * @cmd: the command + * @arg: command arg + * + * This ioctl implements lttng commands: + * LTTNG_STREAM + * Returns an event stream file descriptor or failure. + * + * Channel and event file descriptors also hold a reference on the session. + */ +static +long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + switch (cmd) { + case LTTNG_STREAM: + return lttng_abi_open_stream(file); + default: + return -ENOIOCTLCMD; + } +} + /* TODO: poll */ #if 0 /** @@ -392,6 +510,14 @@ static const struct file_operations lttng_channel_fops = { #endif }; +static const struct file_operations lttng_metadata_fops = { + .release = lttng_channel_release, + .unlocked_ioctl = lttng_metadata_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = lttng_metadata_ioctl, +#endif +}; + static int lttng_event_release(struct inode *inode, struct file *file) {