diff options
Diffstat (limited to 'mm/backing-dev.c')
-rw-r--r-- | mm/backing-dev.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index e8644b1..7c4f9e0 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -4,12 +4,229 @@ #include <linux/fs.h> #include <linux/sched.h> #include <linux/module.h> +#include <linux/writeback.h> +#include <linux/device.h> + + +static struct class *bdi_class; + +#ifdef CONFIG_DEBUG_FS +#include <linux/debugfs.h> +#include <linux/seq_file.h> + +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; + long background_thresh; + long dirty_thresh; + 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); + +int bdi_register(struct backing_dev_info *bdi, struct device *parent, + const char *fmt, ...) +{ + char *name; + va_list args; + int ret = 0; + struct device *dev; + + va_start(args, fmt); + name = kvasprintf(GFP_KERNEL, fmt, args); + va_end(args); + + if (!name) + return -ENOMEM; + + dev = device_create(bdi_class, parent, MKDEV(0, 0), name); + if (IS_ERR(dev)) { + ret = PTR_ERR(dev); + goto exit; + } + + bdi->dev = dev; + dev_set_drvdata(bdi->dev, bdi); + bdi_debug_register(bdi, name); + +exit: + kfree(name); + 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_irq(&bdi->bdi_stat[i], 0); if (err) @@ -33,6 +250,8 @@ 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]); |