From e6c08367b8fc6dce6dfd1106f53f6ef28215b313 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Sun, 8 Jan 2006 01:02:29 -0800 Subject: [PATCH] relayfs: add support for global relay buffers This patch adds the optional is_global outparam to the create_buf_file() callback. This can be used by clients to create a single global relayfs buffer instead of the default per-cpu buffers. This was suggested as being useful for certain debugging applications where it's more convenient to be able to get all the data from a single channel without having to go to the bother of dealing with per-cpu files. Signed-off-by: Tom Zanussi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/relayfs/relay.c | 35 +++++++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 10 deletions(-) (limited to 'fs/relayfs/relay.c') diff --git a/fs/relayfs/relay.c b/fs/relayfs/relay.c index b9bb56903272..2935a6ab8ffa 100644 --- a/fs/relayfs/relay.c +++ b/fs/relayfs/relay.c @@ -86,7 +86,8 @@ static void buf_unmapped_default_callback(struct rchan_buf *buf, static struct dentry *create_buf_file_default_callback(const char *filename, struct dentry *parent, int mode, - struct rchan_buf *buf) + struct rchan_buf *buf, + int *is_global) { return relayfs_create_file(filename, parent, mode, &relayfs_file_operations, buf); @@ -170,14 +171,16 @@ static inline void __relay_reset(struct rchan_buf *buf, unsigned int init) void relay_reset(struct rchan *chan) { unsigned int i; + struct rchan_buf *prev = NULL; if (!chan) return; for (i = 0; i < NR_CPUS; i++) { - if (!chan->buf[i]) - continue; + if (!chan->buf[i] || chan->buf[i] == prev) + break; __relay_reset(chan->buf[i], 0); + prev = chan->buf[i]; } } @@ -188,18 +191,22 @@ void relay_reset(struct rchan *chan) */ static struct rchan_buf *relay_open_buf(struct rchan *chan, const char *filename, - struct dentry *parent) + struct dentry *parent, + int *is_global) { struct rchan_buf *buf; struct dentry *dentry; + if (*is_global) + return chan->buf[0]; + buf = relay_create_buf(chan); if (!buf) return NULL; /* Create file in fs */ dentry = chan->cb->create_buf_file(filename, parent, S_IRUSR, - buf); + buf, is_global); if (!dentry) { relay_destroy_buf(buf); return NULL; @@ -273,6 +280,7 @@ struct rchan *relay_open(const char *base_filename, unsigned int i; struct rchan *chan; char *tmpname; + int is_global = 0; if (!base_filename) return NULL; @@ -297,7 +305,8 @@ struct rchan *relay_open(const char *base_filename, for_each_online_cpu(i) { sprintf(tmpname, "%s%d", base_filename, i); - chan->buf[i] = relay_open_buf(chan, tmpname, parent); + chan->buf[i] = relay_open_buf(chan, tmpname, parent, + &is_global); chan->buf[i]->cpu = i; if (!chan->buf[i]) goto free_bufs; @@ -311,6 +320,8 @@ free_bufs: if (!chan->buf[i]) break; relay_close_buf(chan->buf[i]); + if (is_global) + break; } kfree(tmpname); @@ -420,14 +431,16 @@ void relay_destroy_channel(struct kref *kref) void relay_close(struct rchan *chan) { unsigned int i; + struct rchan_buf *prev = NULL; if (!chan) return; for (i = 0; i < NR_CPUS; i++) { - if (!chan->buf[i]) - continue; + if (!chan->buf[i] || chan->buf[i] == prev) + break; relay_close_buf(chan->buf[i]); + prev = chan->buf[i]; } if (chan->last_toobig) @@ -447,14 +460,16 @@ void relay_close(struct rchan *chan) void relay_flush(struct rchan *chan) { unsigned int i; + struct rchan_buf *prev = NULL; if (!chan) return; for (i = 0; i < NR_CPUS; i++) { - if (!chan->buf[i]) - continue; + if (!chan->buf[i] || chan->buf[i] == prev) + break; relay_switch_subbuf(chan->buf[i], 0); + prev = chan->buf[i]; } } -- cgit v1.2.3-59-g8ed1b