X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Frelay.c;h=577f251c7e28104f621d542a199169053a589c8b;hb=ebc610e5bc76df073221e64e86c3f7533a09ea40;hp=1d63ecddfa7018cd4a14f8b6dc24c352a9ddc447;hpb=4c78a6639386f9e7399fbc0d0a173d4cc1a3e9bf;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/relay.c b/kernel/relay.c index 1d63ecd..577f251 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -7,6 +7,8 @@ * Copyright (C) 1999-2005 - Karim Yaghmour (karim@opersys.com) * * Moved to kernel/relay.c by Paul Mundt, 2006. + * November 2006 - CPU hotplug support by Mathieu Desnoyers + * (mathieu.desnoyers@polymtl.ca) * * This file is released under the GPL. */ @@ -18,6 +20,11 @@ #include #include #include +#include + +/* list of open channels, for cpu hotplug */ +static DEFINE_MUTEX(relay_channels_mutex); +static LIST_HEAD(relay_channels); /* * close() vm_op implementation for relay file mapping. @@ -138,7 +145,7 @@ depopulate: */ struct rchan_buf *relay_create_buf(struct rchan *chan) { - struct rchan_buf *buf = kcalloc(1, sizeof(struct rchan_buf), GFP_KERNEL); + struct rchan_buf *buf = kzalloc(sizeof(struct rchan_buf), GFP_KERNEL); if (!buf) return NULL; @@ -187,6 +194,7 @@ void relay_destroy_buf(struct rchan_buf *buf) __free_page(buf->page_array[i]); kfree(buf->page_array); } + chan->buf[buf->cpu] = NULL; kfree(buf->padding); kfree(buf); kref_put(&chan->kref, relay_destroy_channel); @@ -302,15 +310,16 @@ static struct rchan_callbacks default_channel_callbacks = { /** * wakeup_readers - wake up readers waiting on a channel - * @private: the channel buffer + * @work: work struct that contains the the channel buffer * * This is the work function used to defer reader waking. The * reason waking is deferred is that calling directly from write * causes problems if you're writing from say the scheduler. */ -static void wakeup_readers(void *private) +static void wakeup_readers(struct work_struct *work) { - struct rchan_buf *buf = private; + struct rchan_buf *buf = + container_of(work, struct rchan_buf, wake_readers.work); wake_up_interruptible(&buf->read_wait); } @@ -319,16 +328,16 @@ static void wakeup_readers(void *private) * @buf: the channel buffer * @init: 1 if this is a first-time initialization * - * See relay_reset for description of effect. + * See relay_reset() for description of effect. */ -static inline void __relay_reset(struct rchan_buf *buf, unsigned int init) +static void __relay_reset(struct rchan_buf *buf, unsigned int init) { size_t i; if (init) { init_waitqueue_head(&buf->read_wait); kref_init(&buf->kref); - INIT_WORK(&buf->wake_readers, NULL, NULL); + INIT_DELAYED_WORK(&buf->wake_readers, NULL); } else { cancel_delayed_work(&buf->wake_readers); flush_scheduled_work(); @@ -355,57 +364,75 @@ static inline void __relay_reset(struct rchan_buf *buf, unsigned int init) * and restarting the channel in its initial state. The buffers * are not freed, so any mappings are still in effect. * - * NOTE: Care should be taken that the channel isn't actually + * NOTE. Care should be taken that the channel isn't actually * being used by anything when this call is made. */ 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] || chan->buf[i] == prev) - break; - __relay_reset(chan->buf[i], 0); - prev = chan->buf[i]; + if (chan->is_global && chan->buf[0]) { + __relay_reset(chan->buf[0], 0); + return; } + + mutex_lock(&relay_channels_mutex); + for_each_online_cpu(i) + if (chan->buf[i]) + __relay_reset(chan->buf[i], 0); + mutex_unlock(&relay_channels_mutex); } EXPORT_SYMBOL_GPL(relay_reset); /* * relay_open_buf - create a new relay channel buffer * - * Internal - used by relay_open(). + * used by relay_open() and CPU hotplug. */ -static struct rchan_buf *relay_open_buf(struct rchan *chan, - const char *filename, - struct dentry *parent, - int *is_global) +static struct rchan_buf *relay_open_buf(struct rchan *chan, unsigned int cpu) { - struct rchan_buf *buf; + struct rchan_buf *buf = NULL; struct dentry *dentry; + char *tmpname; - if (*is_global) + if (chan->is_global) return chan->buf[0]; + tmpname = kzalloc(NAME_MAX + 1, GFP_KERNEL); + if (!tmpname) + goto end; + snprintf(tmpname, NAME_MAX, "%s%d", chan->base_filename, cpu); + buf = relay_create_buf(chan); if (!buf) - return NULL; + goto free_name; + + buf->cpu = cpu; + __relay_reset(buf, 1); /* Create file in fs */ - dentry = chan->cb->create_buf_file(filename, parent, S_IRUSR, - buf, is_global); - if (!dentry) { - relay_destroy_buf(buf); - return NULL; - } + dentry = chan->cb->create_buf_file(tmpname, chan->parent, S_IRUSR, + buf, &chan->is_global); + if (!dentry) + goto free_buf; buf->dentry = dentry; - __relay_reset(buf, 1); + if(chan->is_global) { + chan->buf[0] = buf; + buf->cpu = 0; + } + + goto free_name; + +free_buf: + relay_destroy_buf(buf); +free_name: + kfree(tmpname); +end: return buf; } @@ -417,7 +444,7 @@ static struct rchan_buf *relay_open_buf(struct rchan *chan, * The channel buffer and channel buffer data structure are then freed * automatically when the last reference is given up. */ -static inline void relay_close_buf(struct rchan_buf *buf) +static void relay_close_buf(struct rchan_buf *buf) { buf->finalized = 1; cancel_delayed_work(&buf->wake_readers); @@ -425,7 +452,7 @@ static inline void relay_close_buf(struct rchan_buf *buf) kref_put(&buf->kref, relay_remove_buf); } -static inline void setup_callbacks(struct rchan *chan, +static void setup_callbacks(struct rchan *chan, struct rchan_callbacks *cb) { if (!cb) { @@ -447,38 +474,77 @@ static inline void setup_callbacks(struct rchan *chan, } /** + * relay_hotcpu_callback - CPU hotplug callback + * @nb: notifier block + * @action: hotplug action to take + * @hcpu: CPU number + * + * Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD) + */ +static int __cpuinit relay_hotcpu_callback(struct notifier_block *nb, + unsigned long action, + void *hcpu) +{ + unsigned int hotcpu = (unsigned long)hcpu; + struct rchan *chan; + + switch(action) { + case CPU_UP_PREPARE: + mutex_lock(&relay_channels_mutex); + list_for_each_entry(chan, &relay_channels, list) { + if (chan->buf[hotcpu]) + continue; + chan->buf[hotcpu] = relay_open_buf(chan, hotcpu); + if(!chan->buf[hotcpu]) { + printk(KERN_ERR + "relay_hotcpu_callback: cpu %d buffer " + "creation failed\n", hotcpu); + mutex_unlock(&relay_channels_mutex); + return NOTIFY_BAD; + } + } + mutex_unlock(&relay_channels_mutex); + break; + case CPU_DEAD: + /* No need to flush the cpu : will be flushed upon + * final relay_flush() call. */ + break; + } + return NOTIFY_OK; +} + +/** * relay_open - create a new relay channel * @base_filename: base name of files to create * @parent: dentry of parent directory, %NULL for root directory * @subbuf_size: size of sub-buffers * @n_subbufs: number of sub-buffers * @cb: client callback functions + * @private_data: user-defined data * * Returns channel pointer if successful, %NULL otherwise. * * Creates a channel buffer for each cpu using the sizes and * attributes specified. The created channel buffer files * will be named base_filename0...base_filenameN-1. File - * permissions will be S_IRUSR. + * permissions will be %S_IRUSR. */ struct rchan *relay_open(const char *base_filename, struct dentry *parent, size_t subbuf_size, size_t n_subbufs, - struct rchan_callbacks *cb) + struct rchan_callbacks *cb, + void *private_data) { unsigned int i; struct rchan *chan; - char *tmpname; - int is_global = 0; - if (!base_filename) return NULL; if (!(subbuf_size && n_subbufs)) return NULL; - chan = kcalloc(1, sizeof(struct rchan), GFP_KERNEL); + chan = kzalloc(sizeof(struct rchan), GFP_KERNEL); if (!chan) return NULL; @@ -486,38 +552,32 @@ struct rchan *relay_open(const char *base_filename, chan->n_subbufs = n_subbufs; chan->subbuf_size = subbuf_size; chan->alloc_size = FIX_SIZE(subbuf_size * n_subbufs); + chan->parent = parent; + chan->private_data = private_data; + strlcpy(chan->base_filename, base_filename, NAME_MAX); setup_callbacks(chan, cb); kref_init(&chan->kref); - tmpname = kmalloc(NAME_MAX + 1, GFP_KERNEL); - if (!tmpname) - goto free_chan; - + mutex_lock(&relay_channels_mutex); for_each_online_cpu(i) { - sprintf(tmpname, "%s%d", base_filename, i); - chan->buf[i] = relay_open_buf(chan, tmpname, parent, - &is_global); + chan->buf[i] = relay_open_buf(chan, i); if (!chan->buf[i]) goto free_bufs; - - chan->buf[i]->cpu = i; } + list_add(&chan->list, &relay_channels); + mutex_unlock(&relay_channels_mutex); - kfree(tmpname); return chan; free_bufs: - for (i = 0; i < NR_CPUS; i++) { + for_each_online_cpu(i) { if (!chan->buf[i]) break; relay_close_buf(chan->buf[i]); - if (is_global) - break; } - kfree(tmpname); -free_chan: kref_put(&chan->kref, relay_destroy_channel); + mutex_unlock(&relay_channels_mutex); return NULL; } EXPORT_SYMBOL_GPL(relay_open); @@ -549,7 +609,8 @@ size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length) buf->padding[old_subbuf]; smp_mb(); if (waitqueue_active(&buf->read_wait)) { - PREPARE_WORK(&buf->wake_readers, wakeup_readers, buf); + PREPARE_DELAYED_WORK(&buf->wake_readers, + wakeup_readers); schedule_delayed_work(&buf->wake_readers, 1); } } @@ -586,7 +647,7 @@ EXPORT_SYMBOL_GPL(relay_switch_subbuf); * subbufs_consumed should be the number of sub-buffers newly consumed, * not the total consumed. * - * NOTE: Kernel clients don't need to call this function if the channel + * NOTE. Kernel clients don't need to call this function if the channel * mode is 'overwrite'. */ void relay_subbufs_consumed(struct rchan *chan, @@ -617,24 +678,26 @@ EXPORT_SYMBOL_GPL(relay_subbufs_consumed); 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] || chan->buf[i] == prev) - break; - relay_close_buf(chan->buf[i]); - prev = chan->buf[i]; - } + mutex_lock(&relay_channels_mutex); + if (chan->is_global && chan->buf[0]) + relay_close_buf(chan->buf[0]); + else + for_each_possible_cpu(i) + if (chan->buf[i]) + relay_close_buf(chan->buf[i]); if (chan->last_toobig) printk(KERN_WARNING "relay: one or more items not logged " "[item size (%Zd) > sub-buffer size (%Zd)]\n", chan->last_toobig, chan->subbuf_size); + list_del(&chan->list); kref_put(&chan->kref, relay_destroy_channel); + mutex_unlock(&relay_channels_mutex); } EXPORT_SYMBOL_GPL(relay_close); @@ -647,17 +710,20 @@ EXPORT_SYMBOL_GPL(relay_close); 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] || chan->buf[i] == prev) - break; - relay_switch_subbuf(chan->buf[i], 0); - prev = chan->buf[i]; + if (chan->is_global && chan->buf[0]) { + relay_switch_subbuf(chan->buf[0], 0); + return; } + + mutex_lock(&relay_channels_mutex); + for_each_possible_cpu(i) + if (chan->buf[i]) + relay_switch_subbuf(chan->buf[i], 0); + mutex_unlock(&relay_channels_mutex); } EXPORT_SYMBOL_GPL(relay_flush); @@ -682,7 +748,7 @@ static int relay_file_open(struct inode *inode, struct file *filp) * @filp: the file * @vma: the vma describing what to map * - * Calls upon relay_mmap_buf to map the file into user space. + * Calls upon relay_mmap_buf() to map the file into user space. */ static int relay_file_mmap(struct file *filp, struct vm_area_struct *vma) { @@ -824,7 +890,7 @@ static size_t relay_file_read_subbuf_avail(size_t read_pos, * @read_pos: file read position * @buf: relay channel buffer * - * If the read_pos is in the middle of padding, return the + * If the @read_pos is in the middle of padding, return the * position of the first actually available byte, otherwise * return the original value. */ @@ -887,7 +953,7 @@ static int subbuf_read_actor(size_t read_start, from = buf->start + read_start; ret = avail; - if (copy_to_user(desc->arg.data, from, avail)) { + if (copy_to_user(desc->arg.buf, from, avail)) { desc->error = -EFAULT; ret = 0; } @@ -944,27 +1010,19 @@ typedef int (*subbuf_actor_t) (size_t read_start, /* * relay_file_read_subbufs - read count bytes, bridging subbuf boundaries */ -static inline ssize_t relay_file_read_subbufs(struct file *filp, - loff_t *ppos, - size_t count, - subbuf_actor_t subbuf_actor, - read_actor_t actor, - void *target) +static ssize_t relay_file_read_subbufs(struct file *filp, loff_t *ppos, + subbuf_actor_t subbuf_actor, + read_actor_t actor, + read_descriptor_t *desc) { struct rchan_buf *buf = filp->private_data; size_t read_start, avail; - read_descriptor_t desc; int ret; - if (!count) + if (!desc->count) return 0; - desc.written = 0; - desc.count = count; - desc.arg.data = target; - desc.error = 0; - - mutex_lock(&filp->f_dentry->d_inode->i_mutex); + mutex_lock(&filp->f_path.dentry->d_inode->i_mutex); do { if (!relay_file_read_avail(buf, *ppos)) break; @@ -974,19 +1032,19 @@ static inline ssize_t relay_file_read_subbufs(struct file *filp, if (!avail) break; - avail = min(desc.count, avail); - ret = subbuf_actor(read_start, buf, avail, &desc, actor); - if (desc.error < 0) + avail = min(desc->count, avail); + ret = subbuf_actor(read_start, buf, avail, desc, actor); + if (desc->error < 0) break; if (ret) { relay_file_read_consume(buf, read_start, ret); *ppos = relay_file_read_end_pos(buf, read_start, ret); } - } while (desc.count && ret); - mutex_unlock(&filp->f_dentry->d_inode->i_mutex); + } while (desc->count && ret); + mutex_unlock(&filp->f_path.dentry->d_inode->i_mutex); - return desc.written; + return desc->written; } static ssize_t relay_file_read(struct file *filp, @@ -994,8 +1052,13 @@ static ssize_t relay_file_read(struct file *filp, size_t count, loff_t *ppos) { - return relay_file_read_subbufs(filp, ppos, count, subbuf_read_actor, - NULL, buffer); + read_descriptor_t desc; + desc.written = 0; + desc.count = count; + desc.arg.buf = buffer; + desc.error = 0; + return relay_file_read_subbufs(filp, ppos, subbuf_read_actor, + NULL, &desc); } static ssize_t relay_file_sendfile(struct file *filp, @@ -1004,11 +1067,16 @@ static ssize_t relay_file_sendfile(struct file *filp, read_actor_t actor, void *target) { - return relay_file_read_subbufs(filp, ppos, count, subbuf_send_actor, - actor, target); + read_descriptor_t desc; + desc.written = 0; + desc.count = count; + desc.arg.data = target; + desc.error = 0; + return relay_file_read_subbufs(filp, ppos, subbuf_send_actor, + actor, &desc); } -struct file_operations relay_file_operations = { +const struct file_operations relay_file_operations = { .open = relay_file_open, .poll = relay_file_poll, .mmap = relay_file_mmap, @@ -1018,3 +1086,12 @@ struct file_operations relay_file_operations = { .sendfile = relay_file_sendfile, }; EXPORT_SYMBOL_GPL(relay_file_operations); + +static __init int relay_init(void) +{ + + hotcpu_notifier(relay_hotcpu_callback, 0); + return 0; +} + +module_init(relay_init);