diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-bdi | 46 | ||||
| -rw-r--r-- | block/genhd.c | 8 | ||||
| -rw-r--r-- | include/linux/backing-dev.h | 9 | ||||
| -rw-r--r-- | include/linux/writeback.h | 3 | ||||
| -rw-r--r-- | lib/percpu_counter.c | 1 | ||||
| -rw-r--r-- | mm/backing-dev.c | 119 | ||||
| -rw-r--r-- | mm/page-writeback.c | 2 | ||||
| -rw-r--r-- | mm/readahead.c | 8 |
8 files changed, 194 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-bdi b/Documentation/ABI/testing/sysfs-class-bdi new file mode 100644 index 0000000..b800cdd --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-bdi @@ -0,0 +1,46 @@ +What: /sys/class/bdi/<bdi>/ +Date: January 2008 +Contact: Peter Zijlstra <a.p.zijlstra@chello.nl> +Description: + +Provide a place in sysfs for the backing_dev_info object. +This allows us to see and set the various BDI specific variables. + +The <bdi> identifier can be either of the following: + +MAJOR:MINOR + + Device number for block devices, or value of st_dev on + non-block filesystems which provide their own BDI, such as NFS + and FUSE. + +default + + The default backing dev, used for non-block device backed + filesystems which do not provide their own BDI. + +Files under /sys/class/bdi/<bdi>/ +--------------------------------- + +read_ahead_kb (read-write) + + Size of the read-ahead window in kilobytes + +reclaimable_kb (read-only) + + Reclaimable (dirty or unstable) memory destined for writeback + to this device + +writeback_kb (read-only) + + Memory currently under writeback to this device + +dirty_kb (read-only) + + Global threshold for reclaimable + writeback memory + +bdi_dirty_kb (read-only) + + Current threshold on this BDI for reclaimable + writeback + memory + diff --git a/block/genhd.c b/block/genhd.c index 00da521..fda9c7a 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -182,11 +182,17 @@ static int exact_lock(dev_t devt, void *data) */ void add_disk(struct gendisk *disk) { + struct backing_dev_info *bdi; + disk->flags |= GENHD_FL_UP; blk_register_region(MKDEV(disk->major, disk->first_minor), disk->minors, NULL, exact_match, exact_lock, disk); register_disk(disk); blk_register_queue(disk); + + bdi = &disk->queue->backing_dev_info; + bdi_register_dev(bdi, MKDEV(disk->major, disk->first_minor)); + sysfs_create_link(&disk->dev.kobj, &bdi->dev->kobj, "bdi"); } EXPORT_SYMBOL(add_disk); @@ -194,6 +200,8 @@ EXPORT_SYMBOL(del_gendisk); /* in partitions/check.c */ void unlink_gendisk(struct gendisk *disk) { + sysfs_remove_link(&disk->dev.kobj, "bdi"); + bdi_unregister(&disk->queue->backing_dev_info); blk_unregister_queue(disk); blk_unregister_region(MKDEV(disk->major, disk->first_minor), disk->minors); diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index b66fa2b..6d51366 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -11,9 +11,11 @@ #include <linux/percpu_counter.h> #include <linux/log2.h> #include <linux/proportions.h> +#include <linux/kernel.h> #include <asm/atomic.h> struct page; +struct device; /* * Bits in backing_dev_info.state @@ -48,11 +50,18 @@ struct backing_dev_info { struct prop_local_percpu completions; int dirty_exceeded; + + struct device *dev; }; int bdi_init(struct backing_dev_info *bdi); void bdi_destroy(struct backing_dev_info *bdi); +int bdi_register(struct backing_dev_info *bdi, struct device *parent, + const char *fmt, ...); +int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev); +void bdi_unregister(struct backing_dev_info *bdi); + static inline void __add_bdi_stat(struct backing_dev_info *bdi, enum bdi_stat_item item, s64 amount) { diff --git a/include/linux/writeback.h b/include/linux/writeback.h index b7b3362..f462439 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -114,6 +114,9 @@ struct file; int dirty_writeback_centisecs_handler(struct ctl_table *, int, struct file *, void __user *, size_t *, loff_t *); +void get_dirty_limits(long *pbackground, long *pdirty, long *pbdi_dirty, + struct backing_dev_info *bdi); + void page_writeback_init(void); void balance_dirty_pages_ratelimited_nr(struct address_space *mapping, unsigned long nr_pages_dirtied); diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c index 393a0e9..1191744 100644 --- a/lib/percpu_counter.c +++ b/lib/percpu_counter.c @@ -102,6 +102,7 @@ void percpu_counter_destroy(struct percpu_counter *fbc) return; free_percpu(fbc->counters); + fbc->counters = NULL; #ifdef CONFIG_HOTPLUG_CPU mutex_lock(&percpu_counters_lock); list_del(&fbc->list); diff --git a/mm/backing-dev.c b/mm/backing-dev.c index e8644b1..847eabe 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -4,12 +4,129 @@ #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; + +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)) + +BDI_SHOW(reclaimable_kb, K(bdi_stat(bdi, BDI_RECLAIMABLE))) +BDI_SHOW(writeback_kb, K(bdi_stat(bdi, BDI_WRITEBACK))) + +static inline unsigned long get_dirty(struct backing_dev_info *bdi, int i) +{ + unsigned long thresh[3]; + + get_dirty_limits(&thresh[0], &thresh[1], &thresh[2], bdi); + + return thresh[i]; +} + +BDI_SHOW(dirty_kb, K(get_dirty(bdi, 1))) +BDI_SHOW(bdi_dirty_kb, K(get_dirty(bdi, 2))) + +#define __ATTR_RW(attr) __ATTR(attr, 0644, attr##_show, attr##_store) + +static struct device_attribute bdi_dev_attrs[] = { + __ATTR_RW(read_ahead_kb), + __ATTR_RO(reclaimable_kb), + __ATTR_RO(writeback_kb), + __ATTR_RO(dirty_kb), + __ATTR_RO(bdi_dirty_kb), + __ATTR_NULL, +}; + +static __init int bdi_class_init(void) +{ + bdi_class = class_create(THIS_MODULE, "bdi"); + bdi_class->dev_attrs = bdi_dev_attrs; + return 0; +} + +core_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); + +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) { + 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; + for (i = 0; i < NR_BDI_STAT_ITEMS; i++) { err = percpu_counter_init_irq(&bdi->bdi_stat[i], 0); if (err) @@ -33,6 +150,8 @@ 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]); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 5e00f17..e5b6b11 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -300,7 +300,7 @@ static unsigned long determine_dirtyable_memory(void) return x + 1; /* Ensure that we never return 0 */ } -static void +void get_dirty_limits(long *pbackground, long *pdirty, long *pbdi_dirty, struct backing_dev_info *bdi) { diff --git a/mm/readahead.c b/mm/readahead.c index 8762e89..d8723a5 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -235,7 +235,13 @@ unsigned long max_sane_readahead(unsigned long nr) static int __init readahead_init(void) { - return bdi_init(&default_backing_dev_info); + int err; + + err = bdi_init(&default_backing_dev_info); + if (!err) + bdi_register(&default_backing_dev_info, NULL, "default"); + + return err; } subsys_initcall(readahead_init); |