diff options
| -rw-r--r-- | fs/fscache/internal.h | 1 | ||||
| -rw-r--r-- | fs/fscache/page.c | 19 | ||||
| -rw-r--r-- | fs/fscache/stats.c | 6 | ||||
| -rw-r--r-- | fs/nfs/write.c | 3 |
4 files changed, 21 insertions, 8 deletions
diff --git a/fs/fscache/internal.h b/fs/fscache/internal.h index dcb3e1d5dbf6..88a48ccb7d9e 100644 --- a/fs/fscache/internal.h +++ b/fs/fscache/internal.h @@ -200,6 +200,7 @@ extern atomic_t fscache_n_store_vmscan_not_storing; extern atomic_t fscache_n_store_vmscan_gone; extern atomic_t fscache_n_store_vmscan_busy; extern atomic_t fscache_n_store_vmscan_cancelled; +extern atomic_t fscache_n_store_vmscan_wait; extern atomic_t fscache_n_marks; extern atomic_t fscache_n_uncaches; diff --git a/fs/fscache/page.c b/fs/fscache/page.c index 4dbbca162620..f9b2fb3ae492 100644 --- a/fs/fscache/page.c +++ b/fs/fscache/page.c @@ -56,6 +56,7 @@ bool __fscache_maybe_release_page(struct fscache_cookie *cookie, _enter("%p,%p,%x", cookie, page, gfp); +try_again: rcu_read_lock(); val = radix_tree_lookup(&cookie->stores, page->index); if (!val) { @@ -104,11 +105,19 @@ bool __fscache_maybe_release_page(struct fscache_cookie *cookie, return true; page_busy: - /* we might want to wait here, but that could deadlock the allocator as - * the work threads writing to the cache may all end up sleeping - * on memory allocation */ - fscache_stat(&fscache_n_store_vmscan_busy); - return false; + /* We will wait here if we're allowed to, but that could deadlock the + * allocator as the work threads writing to the cache may all end up + * sleeping on memory allocation, so we may need to impose a timeout + * too. */ + if (!(gfp & __GFP_WAIT)) { + fscache_stat(&fscache_n_store_vmscan_busy); + return false; + } + + fscache_stat(&fscache_n_store_vmscan_wait); + __fscache_wait_on_page_write(cookie, page); + gfp &= ~__GFP_WAIT; + goto try_again; } EXPORT_SYMBOL(__fscache_maybe_release_page); diff --git a/fs/fscache/stats.c b/fs/fscache/stats.c index 51cdaee14109..8179e8bc4a3d 100644 --- a/fs/fscache/stats.c +++ b/fs/fscache/stats.c @@ -69,6 +69,7 @@ atomic_t fscache_n_store_vmscan_not_storing; atomic_t fscache_n_store_vmscan_gone; atomic_t fscache_n_store_vmscan_busy; atomic_t fscache_n_store_vmscan_cancelled; +atomic_t fscache_n_store_vmscan_wait; atomic_t fscache_n_marks; atomic_t fscache_n_uncaches; @@ -232,11 +233,12 @@ static int fscache_stats_show(struct seq_file *m, void *v) atomic_read(&fscache_n_store_radix_deletes), atomic_read(&fscache_n_store_pages_over_limit)); - seq_printf(m, "VmScan : nos=%u gon=%u bsy=%u can=%u\n", + seq_printf(m, "VmScan : nos=%u gon=%u bsy=%u can=%u wt=%u\n", atomic_read(&fscache_n_store_vmscan_not_storing), atomic_read(&fscache_n_store_vmscan_gone), atomic_read(&fscache_n_store_vmscan_busy), - atomic_read(&fscache_n_store_vmscan_cancelled)); + atomic_read(&fscache_n_store_vmscan_cancelled), + atomic_read(&fscache_n_store_vmscan_wait)); seq_printf(m, "Ops : pend=%u run=%u enq=%u can=%u rej=%u\n", atomic_read(&fscache_n_op_pend), diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 5209916e1222..b673be31590e 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1794,7 +1794,8 @@ int nfs_migrate_page(struct address_space *mapping, struct page *newpage, if (PagePrivate(page)) return -EBUSY; - nfs_fscache_release_page(page, GFP_KERNEL); + if (!nfs_fscache_release_page(page, GFP_KERNEL)) + return -EBUSY; return migrate_page(mapping, newpage, page, mode); } |