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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-10-24 01:20:57 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-10-24 01:20:57 +0300 |
commit | ea1ee5ff1b500ccdc64782ecef13d276afb08f14 (patch) | |
tree | 085cb2fc7a5b4b4395f1f13cb05d989aa18bce8e /mm | |
parent | ef594c421a0f96197f28d205e2ee58a83c1e0e37 (diff) | |
parent | e27c5b9d23168cc2cb8fec147ae7ed1f7a2005c3 (diff) | |
download | linux-ea1ee5ff1b500ccdc64782ecef13d276afb08f14.tar.xz |
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block layer fixes from Jens Axboe:
"A final set of fixes for 4.3.
It is (again) bigger than I would have liked, but it's all been
through the testing mill and has been carefully reviewed by multiple
parties. Each fix is either a regression fix for this cycle, or is
marked stable. You can scold me at KS. The pull request contains:
- Three simple fixes for NVMe, fixing regressions since 4.3. From
Arnd, Christoph, and Keith.
- A single xen-blkfront fix from Cathy, fixing a NULL dereference if
an error is returned through the staste change callback.
- Fixup for some bad/sloppy code in nbd that got introduced earlier
in this cycle. From Markus Pargmann.
- A blk-mq tagset use-after-free fix from Junichi.
- A backing device lifetime fix from Tejun, fixing a crash.
- And finally, a set of regression/stable fixes for cgroup writeback
from Tejun"
* 'for-linus' of git://git.kernel.dk/linux-block:
writeback: remove broken rbtree_postorder_for_each_entry_safe() usage in cgwb_bdi_destroy()
NVMe: Fix memory leak on retried commands
block: don't release bdi while request_queue has live references
nvme: use an integer value to Linux errno values
blk-mq: fix use-after-free in blk_mq_free_tag_set()
nvme: fix 32-bit build warning
writeback: fix incorrect calculation of available memory for memcg domains
writeback: memcg dirty_throttle_control should be initialized with wb->memcg_completions
writeback: bdi_writeback iteration must not skip dying ones
writeback: fix bdi_writeback iteration in wakeup_dirtytime_writeback()
writeback: laptop_mode_timer_fn() needs rcu_read_lock() around bdi_writeback iteration
nbd: Add locking for tasks
xen-blkfront: check for null drvdata in blkback_changed (XenbusStateClosing)
Diffstat (limited to 'mm')
-rw-r--r-- | mm/backing-dev.c | 36 | ||||
-rw-r--r-- | mm/memcontrol.c | 35 | ||||
-rw-r--r-- | mm/page-writeback.c | 54 |
3 files changed, 79 insertions, 46 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 2df8ddcb0ca0..619984fc07ec 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -480,6 +480,10 @@ static void cgwb_release_workfn(struct work_struct *work) release_work); struct backing_dev_info *bdi = wb->bdi; + spin_lock_irq(&cgwb_lock); + list_del_rcu(&wb->bdi_node); + spin_unlock_irq(&cgwb_lock); + wb_shutdown(wb); css_put(wb->memcg_css); @@ -575,6 +579,7 @@ static int cgwb_create(struct backing_dev_info *bdi, ret = radix_tree_insert(&bdi->cgwb_tree, memcg_css->id, wb); if (!ret) { atomic_inc(&bdi->usage_cnt); + list_add_tail_rcu(&wb->bdi_node, &bdi->wb_list); list_add(&wb->memcg_node, memcg_cgwb_list); list_add(&wb->blkcg_node, blkcg_cgwb_list); css_get(memcg_css); @@ -676,7 +681,7 @@ static int cgwb_bdi_init(struct backing_dev_info *bdi) static void cgwb_bdi_destroy(struct backing_dev_info *bdi) { struct radix_tree_iter iter; - struct bdi_writeback_congested *congested, *congested_n; + struct rb_node *rbn; void **slot; WARN_ON(test_bit(WB_registered, &bdi->wb.state)); @@ -686,9 +691,11 @@ static void cgwb_bdi_destroy(struct backing_dev_info *bdi) radix_tree_for_each_slot(slot, &bdi->cgwb_tree, &iter, 0) cgwb_kill(*slot); - rbtree_postorder_for_each_entry_safe(congested, congested_n, - &bdi->cgwb_congested_tree, rb_node) { - rb_erase(&congested->rb_node, &bdi->cgwb_congested_tree); + while ((rbn = rb_first(&bdi->cgwb_congested_tree))) { + struct bdi_writeback_congested *congested = + rb_entry(rbn, struct bdi_writeback_congested, rb_node); + + rb_erase(rbn, &bdi->cgwb_congested_tree); congested->bdi = NULL; /* mark @congested unlinked */ } @@ -764,15 +771,22 @@ static void cgwb_bdi_destroy(struct backing_dev_info *bdi) { } int bdi_init(struct backing_dev_info *bdi) { + int ret; + bdi->dev = NULL; bdi->min_ratio = 0; bdi->max_ratio = 100; bdi->max_prop_frac = FPROP_FRAC_BASE; INIT_LIST_HEAD(&bdi->bdi_list); + INIT_LIST_HEAD(&bdi->wb_list); init_waitqueue_head(&bdi->wb_waitq); - return cgwb_bdi_init(bdi); + ret = cgwb_bdi_init(bdi); + + list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list); + + return ret; } EXPORT_SYMBOL(bdi_init); @@ -823,7 +837,7 @@ static void bdi_remove_from_list(struct backing_dev_info *bdi) synchronize_rcu_expedited(); } -void bdi_destroy(struct backing_dev_info *bdi) +void bdi_unregister(struct backing_dev_info *bdi) { /* make sure nobody finds us on the bdi_list anymore */ bdi_remove_from_list(bdi); @@ -835,9 +849,19 @@ void bdi_destroy(struct backing_dev_info *bdi) device_unregister(bdi->dev); bdi->dev = NULL; } +} +void bdi_exit(struct backing_dev_info *bdi) +{ + WARN_ON_ONCE(bdi->dev); wb_exit(&bdi->wb); } + +void bdi_destroy(struct backing_dev_info *bdi) +{ + bdi_unregister(bdi); + bdi_exit(bdi); +} EXPORT_SYMBOL(bdi_destroy); /* diff --git a/mm/memcontrol.c b/mm/memcontrol.c index d9b5c817dce8..c57c4423c688 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3741,44 +3741,43 @@ struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb) /** * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg * @wb: bdi_writeback in question - * @pavail: out parameter for number of available pages + * @pfilepages: out parameter for number of file pages + * @pheadroom: out parameter for number of allocatable pages according to memcg * @pdirty: out parameter for number of dirty pages * @pwriteback: out parameter for number of pages under writeback * - * Determine the numbers of available, dirty, and writeback pages in @wb's - * memcg. Dirty and writeback are self-explanatory. Available is a bit - * more involved. + * Determine the numbers of file, headroom, dirty, and writeback pages in + * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom + * is a bit more involved. * - * A memcg's headroom is "min(max, high) - used". The available memory is - * calculated as the lowest headroom of itself and the ancestors plus the - * number of pages already being used for file pages. Note that this - * doesn't consider the actual amount of available memory in the system. - * The caller should further cap *@pavail accordingly. + * A memcg's headroom is "min(max, high) - used". In the hierarchy, the + * headroom is calculated as the lowest headroom of itself and the + * ancestors. Note that this doesn't consider the actual amount of + * available memory in the system. The caller should further cap + * *@pheadroom accordingly. */ -void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pavail, - unsigned long *pdirty, unsigned long *pwriteback) +void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, + unsigned long *pheadroom, unsigned long *pdirty, + unsigned long *pwriteback) { struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); struct mem_cgroup *parent; - unsigned long head_room = PAGE_COUNTER_MAX; - unsigned long file_pages; *pdirty = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_DIRTY); /* this should eventually include NR_UNSTABLE_NFS */ *pwriteback = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_WRITEBACK); + *pfilepages = mem_cgroup_nr_lru_pages(memcg, (1 << LRU_INACTIVE_FILE) | + (1 << LRU_ACTIVE_FILE)); + *pheadroom = PAGE_COUNTER_MAX; - file_pages = mem_cgroup_nr_lru_pages(memcg, (1 << LRU_INACTIVE_FILE) | - (1 << LRU_ACTIVE_FILE)); while ((parent = parent_mem_cgroup(memcg))) { unsigned long ceiling = min(memcg->memory.limit, memcg->high); unsigned long used = page_counter_read(&memcg->memory); - head_room = min(head_room, ceiling - min(ceiling, used)); + *pheadroom = min(*pheadroom, ceiling - min(ceiling, used)); memcg = parent; } - - *pavail = file_pages + head_room; } #else /* CONFIG_CGROUP_WRITEBACK */ diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 0a931cdd4f6b..2c90357c34ea 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -145,9 +145,6 @@ struct dirty_throttle_control { unsigned long pos_ratio; }; -#define DTC_INIT_COMMON(__wb) .wb = (__wb), \ - .wb_completions = &(__wb)->completions - /* * Length of period for aging writeout fractions of bdis. This is an * arbitrarily chosen number. The longer the period, the slower fractions will @@ -157,12 +154,16 @@ struct dirty_throttle_control { #ifdef CONFIG_CGROUP_WRITEBACK -#define GDTC_INIT(__wb) .dom = &global_wb_domain, \ - DTC_INIT_COMMON(__wb) +#define GDTC_INIT(__wb) .wb = (__wb), \ + .dom = &global_wb_domain, \ + .wb_completions = &(__wb)->completions + #define GDTC_INIT_NO_WB .dom = &global_wb_domain -#define MDTC_INIT(__wb, __gdtc) .dom = mem_cgroup_wb_domain(__wb), \ - .gdtc = __gdtc, \ - DTC_INIT_COMMON(__wb) + +#define MDTC_INIT(__wb, __gdtc) .wb = (__wb), \ + .dom = mem_cgroup_wb_domain(__wb), \ + .wb_completions = &(__wb)->memcg_completions, \ + .gdtc = __gdtc static bool mdtc_valid(struct dirty_throttle_control *dtc) { @@ -213,7 +214,8 @@ static void wb_min_max_ratio(struct bdi_writeback *wb, #else /* CONFIG_CGROUP_WRITEBACK */ -#define GDTC_INIT(__wb) DTC_INIT_COMMON(__wb) +#define GDTC_INIT(__wb) .wb = (__wb), \ + .wb_completions = &(__wb)->completions #define GDTC_INIT_NO_WB #define MDTC_INIT(__wb, __gdtc) @@ -682,13 +684,19 @@ static unsigned long hard_dirty_limit(struct wb_domain *dom, return max(thresh, dom->dirty_limit); } -/* memory available to a memcg domain is capped by system-wide clean memory */ -static void mdtc_cap_avail(struct dirty_throttle_control *mdtc) +/* + * Memory which can be further allocated to a memcg domain is capped by + * system-wide clean memory excluding the amount being used in the domain. + */ +static void mdtc_calc_avail(struct dirty_throttle_control *mdtc, + unsigned long filepages, unsigned long headroom) { struct dirty_throttle_control *gdtc = mdtc_gdtc(mdtc); - unsigned long clean = gdtc->avail - min(gdtc->avail, gdtc->dirty); + unsigned long clean = filepages - min(filepages, mdtc->dirty); + unsigned long global_clean = gdtc->avail - min(gdtc->avail, gdtc->dirty); + unsigned long other_clean = global_clean - min(global_clean, clean); - mdtc->avail = min(mdtc->avail, clean); + mdtc->avail = filepages + min(headroom, other_clean); } /** @@ -1562,16 +1570,16 @@ static void balance_dirty_pages(struct address_space *mapping, } if (mdtc) { - unsigned long writeback; + unsigned long filepages, headroom, writeback; /* * If @wb belongs to !root memcg, repeat the same * basic calculations for the memcg domain. */ - mem_cgroup_wb_stats(wb, &mdtc->avail, &mdtc->dirty, - &writeback); - mdtc_cap_avail(mdtc); + mem_cgroup_wb_stats(wb, &filepages, &headroom, + &mdtc->dirty, &writeback); mdtc->dirty += writeback; + mdtc_calc_avail(mdtc, filepages, headroom); domain_dirty_limits(mdtc); @@ -1893,10 +1901,11 @@ bool wb_over_bg_thresh(struct bdi_writeback *wb) return true; if (mdtc) { - unsigned long writeback; + unsigned long filepages, headroom, writeback; - mem_cgroup_wb_stats(wb, &mdtc->avail, &mdtc->dirty, &writeback); - mdtc_cap_avail(mdtc); + mem_cgroup_wb_stats(wb, &filepages, &headroom, &mdtc->dirty, + &writeback); + mdtc_calc_avail(mdtc, filepages, headroom); domain_dirty_limits(mdtc); /* ditto, ignore writeback */ if (mdtc->dirty > mdtc->bg_thresh) @@ -1956,7 +1965,6 @@ void laptop_mode_timer_fn(unsigned long data) int nr_pages = global_page_state(NR_FILE_DIRTY) + global_page_state(NR_UNSTABLE_NFS); struct bdi_writeback *wb; - struct wb_iter iter; /* * We want to write everything out, not just down to the dirty @@ -1965,10 +1973,12 @@ void laptop_mode_timer_fn(unsigned long data) if (!bdi_has_dirty_io(&q->backing_dev_info)) return; - bdi_for_each_wb(wb, &q->backing_dev_info, &iter, 0) + rcu_read_lock(); + list_for_each_entry_rcu(wb, &q->backing_dev_info.wb_list, bdi_node) if (wb_has_dirty_io(wb)) wb_start_writeback(wb, nr_pages, true, WB_REASON_LAPTOP_TIMER); + rcu_read_unlock(); } /* |