diff options
| -rw-r--r-- | fs/btrfs/extent_map.c | 22 | ||||
| -rw-r--r-- | fs/btrfs/super.c | 10 |
2 files changed, 16 insertions, 16 deletions
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c index 23b65dc73c00..10ac5f657e38 100644 --- a/fs/btrfs/extent_map.c +++ b/fs/btrfs/extent_map.c @@ -1147,8 +1147,7 @@ static long btrfs_scan_inode(struct btrfs_inode *inode, struct btrfs_em_shrink_c return 0; /* - * We want to be fast because we can be called from any path trying to - * allocate memory, so if the lock is busy we don't want to spend time + * We want to be fast so if the lock is busy we don't want to spend time * waiting for it - either some task is about to do IO for the inode or * we may have another task shrinking extent maps, here in this code, so * skip this inode. @@ -1191,9 +1190,7 @@ next: /* * Stop if we need to reschedule or there's contention on the * lock. This is to avoid slowing other tasks trying to take the - * lock and because the shrinker might be called during a memory - * allocation path and we want to avoid taking a very long time - * and slowing down all sorts of tasks. + * lock. */ if (need_resched() || rwlock_needbreak(&tree->lock)) break; @@ -1222,12 +1219,7 @@ static long btrfs_scan_root(struct btrfs_root *root, struct btrfs_em_shrink_ctx if (ctx->scanned >= ctx->nr_to_scan) break; - /* - * We may be called from memory allocation paths, so we don't - * want to take too much time and slowdown tasks. - */ - if (need_resched()) - break; + cond_resched(); inode = btrfs_find_first_inode(root, min_ino); } @@ -1285,14 +1277,12 @@ long btrfs_free_extent_maps(struct btrfs_fs_info *fs_info, long nr_to_scan) ctx.last_ino); } - /* - * We may be called from memory allocation paths, so we don't want to - * take too much time and slowdown tasks, so stop if we need reschedule. - */ - while (ctx.scanned < ctx.nr_to_scan && !need_resched()) { + while (ctx.scanned < ctx.nr_to_scan) { struct btrfs_root *root; unsigned long count; + cond_resched(); + spin_lock(&fs_info->fs_roots_radix_lock); count = radix_tree_gang_lookup(&fs_info->fs_roots_radix, (void **)&root, diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 83478deada3b..11044e9e2cb1 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -28,6 +28,7 @@ #include <linux/btrfs.h> #include <linux/security.h> #include <linux/fs_parser.h> +#include <linux/swap.h> #include "messages.h" #include "delayed-inode.h" #include "ctree.h" @@ -2409,6 +2410,15 @@ static long btrfs_free_cached_objects(struct super_block *sb, struct shrink_cont const long nr_to_scan = min_t(unsigned long, LONG_MAX, sc->nr_to_scan); struct btrfs_fs_info *fs_info = btrfs_sb(sb); + /* + * We may be called from any task trying to allocate memory and we don't + * want to slow it down with scanning and dropping extent maps. It would + * also cause heavy lock contention if many tasks concurrently enter + * here. Therefore only allow kswapd tasks to scan and drop extent maps. + */ + if (!current_is_kswapd()) + return 0; + return btrfs_free_extent_maps(fs_info, nr_to_scan); } |