diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-bdi | 5 | ||||
| -rw-r--r-- | block/blk-integrity.c | 4 | ||||
| -rw-r--r-- | include/linux/backing-dev.h | 6 | ||||
| -rw-r--r-- | mm/backing-dev.c | 11 |
4 files changed, 26 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-bdi b/Documentation/ABI/testing/sysfs-class-bdi index 5f500977b42f..d773d5697cf5 100644 --- a/Documentation/ABI/testing/sysfs-class-bdi +++ b/Documentation/ABI/testing/sysfs-class-bdi @@ -48,3 +48,8 @@ max_ratio (read-write) most of the write-back cache. For example in case of an NFS mount that is prone to get stuck, or a FUSE mount which cannot be trusted to play fair. + +stable_pages_required (read-only) + + If set, the backing device requires that all pages comprising a write + request must not be changed until writeout is complete. diff --git a/block/blk-integrity.c b/block/blk-integrity.c index da2a818c3a92..dabd221857e1 100644 --- a/block/blk-integrity.c +++ b/block/blk-integrity.c @@ -420,6 +420,8 @@ int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template) } else bi->name = bi_unsupported_name; + disk->queue->backing_dev_info.capabilities |= BDI_CAP_STABLE_WRITES; + return 0; } EXPORT_SYMBOL(blk_integrity_register); @@ -438,6 +440,8 @@ void blk_integrity_unregister(struct gendisk *disk) if (!disk || !disk->integrity) return; + disk->queue->backing_dev_info.capabilities &= ~BDI_CAP_STABLE_WRITES; + bi = disk->integrity; kobject_uevent(&bi->kobj, KOBJ_REMOVE); diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 12731a19ef06..350459910fe1 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -254,6 +254,7 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); #define BDI_CAP_EXEC_MAP 0x00000040 #define BDI_CAP_NO_ACCT_WB 0x00000080 #define BDI_CAP_SWAP_BACKED 0x00000100 +#define BDI_CAP_STABLE_WRITES 0x00000200 #define BDI_CAP_VMFLAGS \ (BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP) @@ -308,6 +309,11 @@ long wait_iff_congested(struct zone *zone, int sync, long timeout); int pdflush_proc_obsolete(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); +static inline bool bdi_cap_stable_pages_required(struct backing_dev_info *bdi) +{ + return bdi->capabilities & BDI_CAP_STABLE_WRITES; +} + static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi) { return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK); diff --git a/mm/backing-dev.c b/mm/backing-dev.c index d3ca2b3ee176..41733c5dc820 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -221,12 +221,23 @@ static ssize_t max_ratio_store(struct device *dev, } BDI_SHOW(max_ratio, bdi->max_ratio) +static ssize_t stable_pages_required_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, "%d\n", + bdi_cap_stable_pages_required(bdi) ? 1 : 0); +} + #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_RO(stable_pages_required), __ATTR_NULL, }; |