X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=mm%2Fbacking-dev.c;h=493b468a503541fd65b64872eece6fb7228e36fa;hb=435462c6e639065460e91903d6bd2af0f5762fde;hp=841901a955955a8be07b88a5e75658743c0af5ef;hpb=c4dc4beed23827e155d7cbc2a1ffa3949eddd194;p=safe%2Fjmp%2Flinux-2.6 diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 841901a..493b468 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -2,8 +2,281 @@ #include #include #include +#include #include #include +#include +#include + +void default_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) +{ +} +EXPORT_SYMBOL(default_unplug_io_fn); + +struct backing_dev_info default_backing_dev_info = { + .ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE, + .state = 0, + .capabilities = BDI_CAP_MAP_COPY, + .unplug_io_fn = default_unplug_io_fn, +}; +EXPORT_SYMBOL_GPL(default_backing_dev_info); + +static struct class *bdi_class; + +#ifdef CONFIG_DEBUG_FS +#include +#include + +static struct dentry *bdi_debug_root; + +static void bdi_debug_init(void) +{ + bdi_debug_root = debugfs_create_dir("bdi", NULL); +} + +static int bdi_debug_stats_show(struct seq_file *m, void *v) +{ + struct backing_dev_info *bdi = m->private; + unsigned long background_thresh; + unsigned long dirty_thresh; + unsigned long bdi_thresh; + + get_dirty_limits(&background_thresh, &dirty_thresh, &bdi_thresh, bdi); + +#define K(x) ((x) << (PAGE_SHIFT - 10)) + seq_printf(m, + "BdiWriteback: %8lu kB\n" + "BdiReclaimable: %8lu kB\n" + "BdiDirtyThresh: %8lu kB\n" + "DirtyThresh: %8lu kB\n" + "BackgroundThresh: %8lu kB\n", + (unsigned long) K(bdi_stat(bdi, BDI_WRITEBACK)), + (unsigned long) K(bdi_stat(bdi, BDI_RECLAIMABLE)), + K(bdi_thresh), + K(dirty_thresh), + K(background_thresh)); +#undef K + + return 0; +} + +static int bdi_debug_stats_open(struct inode *inode, struct file *file) +{ + return single_open(file, bdi_debug_stats_show, inode->i_private); +} + +static const struct file_operations bdi_debug_stats_fops = { + .open = bdi_debug_stats_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static void bdi_debug_register(struct backing_dev_info *bdi, const char *name) +{ + bdi->debug_dir = debugfs_create_dir(name, bdi_debug_root); + bdi->debug_stats = debugfs_create_file("stats", 0444, bdi->debug_dir, + bdi, &bdi_debug_stats_fops); +} + +static void bdi_debug_unregister(struct backing_dev_info *bdi) +{ + debugfs_remove(bdi->debug_stats); + debugfs_remove(bdi->debug_dir); +} +#else +static inline void bdi_debug_init(void) +{ +} +static inline void bdi_debug_register(struct backing_dev_info *bdi, + const char *name) +{ +} +static inline void bdi_debug_unregister(struct backing_dev_info *bdi) +{ +} +#endif + +static ssize_t read_ahead_kb_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct backing_dev_info *bdi = dev_get_drvdata(dev); + char *end; + unsigned long read_ahead_kb; + ssize_t ret = -EINVAL; + + read_ahead_kb = simple_strtoul(buf, &end, 10); + if (*buf && (end[0] == '\0' || (end[0] == '\n' && end[1] == '\0'))) { + bdi->ra_pages = read_ahead_kb >> (PAGE_SHIFT - 10); + ret = count; + } + return ret; +} + +#define K(pages) ((pages) << (PAGE_SHIFT - 10)) + +#define BDI_SHOW(name, expr) \ +static ssize_t name##_show(struct device *dev, \ + struct device_attribute *attr, char *page) \ +{ \ + struct backing_dev_info *bdi = dev_get_drvdata(dev); \ + \ + return snprintf(page, PAGE_SIZE-1, "%lld\n", (long long)expr); \ +} + +BDI_SHOW(read_ahead_kb, K(bdi->ra_pages)) + +static ssize_t min_ratio_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct backing_dev_info *bdi = dev_get_drvdata(dev); + char *end; + unsigned int ratio; + ssize_t ret = -EINVAL; + + ratio = simple_strtoul(buf, &end, 10); + if (*buf && (end[0] == '\0' || (end[0] == '\n' && end[1] == '\0'))) { + ret = bdi_set_min_ratio(bdi, ratio); + if (!ret) + ret = count; + } + return ret; +} +BDI_SHOW(min_ratio, bdi->min_ratio) + +static ssize_t max_ratio_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct backing_dev_info *bdi = dev_get_drvdata(dev); + char *end; + unsigned int ratio; + ssize_t ret = -EINVAL; + + ratio = simple_strtoul(buf, &end, 10); + if (*buf && (end[0] == '\0' || (end[0] == '\n' && end[1] == '\0'))) { + ret = bdi_set_max_ratio(bdi, ratio); + if (!ret) + ret = count; + } + return ret; +} +BDI_SHOW(max_ratio, bdi->max_ratio) + +#define __ATTR_RW(attr) __ATTR(attr, 0644, attr##_show, attr##_store) + +static struct device_attribute bdi_dev_attrs[] = { + __ATTR_RW(read_ahead_kb), + __ATTR_RW(min_ratio), + __ATTR_RW(max_ratio), + __ATTR_NULL, +}; + +static __init int bdi_class_init(void) +{ + bdi_class = class_create(THIS_MODULE, "bdi"); + bdi_class->dev_attrs = bdi_dev_attrs; + bdi_debug_init(); + return 0; +} +postcore_initcall(bdi_class_init); + +static int __init default_bdi_init(void) +{ + int err; + + err = bdi_init(&default_backing_dev_info); + if (!err) + bdi_register(&default_backing_dev_info, NULL, "default"); + + return err; +} +subsys_initcall(default_bdi_init); + +int bdi_register(struct backing_dev_info *bdi, struct device *parent, + const char *fmt, ...) +{ + va_list args; + int ret = 0; + struct device *dev; + + if (bdi->dev) /* The driver needs to use separate queues per device */ + goto exit; + + va_start(args, fmt); + dev = device_create_vargs(bdi_class, parent, MKDEV(0, 0), bdi, fmt, args); + va_end(args); + if (IS_ERR(dev)) { + ret = PTR_ERR(dev); + goto exit; + } + + bdi->dev = dev; + bdi_debug_register(bdi, dev_name(dev)); + +exit: + return ret; +} +EXPORT_SYMBOL(bdi_register); + +int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev) +{ + return bdi_register(bdi, NULL, "%u:%u", MAJOR(dev), MINOR(dev)); +} +EXPORT_SYMBOL(bdi_register_dev); + +void bdi_unregister(struct backing_dev_info *bdi) +{ + if (bdi->dev) { + bdi_debug_unregister(bdi); + device_unregister(bdi->dev); + bdi->dev = NULL; + } +} +EXPORT_SYMBOL(bdi_unregister); + +int bdi_init(struct backing_dev_info *bdi) +{ + int i; + int err; + + bdi->dev = NULL; + + bdi->min_ratio = 0; + bdi->max_ratio = 100; + bdi->max_prop_frac = PROP_FRAC_BASE; + + for (i = 0; i < NR_BDI_STAT_ITEMS; i++) { + err = percpu_counter_init(&bdi->bdi_stat[i], 0); + if (err) + goto err; + } + + bdi->dirty_exceeded = 0; + err = prop_local_init_percpu(&bdi->completions); + + if (err) { +err: + while (i--) + percpu_counter_destroy(&bdi->bdi_stat[i]); + } + + return err; +} +EXPORT_SYMBOL(bdi_init); + +void bdi_destroy(struct backing_dev_info *bdi) +{ + int i; + + bdi_unregister(bdi); + + for (i = 0; i < NR_BDI_STAT_ITEMS; i++) + percpu_counter_destroy(&bdi->bdi_stat[i]); + + prop_local_destroy_percpu(&bdi->completions); +} +EXPORT_SYMBOL(bdi_destroy); static wait_queue_head_t congestion_wqh[2] = { __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]), @@ -11,12 +284,12 @@ static wait_queue_head_t congestion_wqh[2] = { }; -void clear_bdi_congested(struct backing_dev_info *bdi, int rw) +void clear_bdi_congested(struct backing_dev_info *bdi, int sync) { enum bdi_state bit; - wait_queue_head_t *wqh = &congestion_wqh[rw]; + wait_queue_head_t *wqh = &congestion_wqh[sync]; - bit = (rw == WRITE) ? BDI_write_congested : BDI_read_congested; + bit = sync ? BDI_sync_congested : BDI_async_congested; clear_bit(bit, &bdi->state); smp_mb__after_clear_bit(); if (waitqueue_active(wqh)) @@ -24,11 +297,11 @@ void clear_bdi_congested(struct backing_dev_info *bdi, int rw) } EXPORT_SYMBOL(clear_bdi_congested); -void set_bdi_congested(struct backing_dev_info *bdi, int rw) +void set_bdi_congested(struct backing_dev_info *bdi, int sync) { enum bdi_state bit; - bit = (rw == WRITE) ? BDI_write_congested : BDI_read_congested; + bit = sync ? BDI_sync_congested : BDI_async_congested; set_bit(bit, &bdi->state); } EXPORT_SYMBOL(set_bdi_congested); @@ -54,3 +327,4 @@ long congestion_wait(int rw, long timeout) return ret; } EXPORT_SYMBOL(congestion_wait); +