Extents mapping a swap file should remain pinned in memory in order to avoid doing allocations to look up an extent when we're already low on memory. Rather than overloading EXTENT_FLAG_PINNED, add a new flag specifically for this purpose.
Signed-off-by: Omar Sandoval <[email protected]> --- fs/btrfs/extent_io.c | 1 + fs/btrfs/extent_map.h | 1 + fs/btrfs/inode.c | 1 + include/trace/events/btrfs.h | 3 ++- 4 files changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index bf3f424..36166d0 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4244,6 +4244,7 @@ int try_release_extent_mapping(struct extent_map_tree *map, break; } if (test_bit(EXTENT_FLAG_PINNED, &em->flags) || + test_bit(EXTENT_FLAG_SWAPFILE, &em->flags) || em->start != start) { write_unlock(&map->lock); free_extent_map(em); diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h index b2991fd..93b9548 100644 --- a/fs/btrfs/extent_map.h +++ b/fs/btrfs/extent_map.h @@ -16,6 +16,7 @@ #define EXTENT_FLAG_LOGGING 4 /* Logging this extent */ #define EXTENT_FLAG_FILLING 5 /* Filling in a preallocated extent */ #define EXTENT_FLAG_FS_MAPPING 6 /* filesystem extent mapping type */ +#define EXTENT_FLAG_SWAPFILE 7 /* this extent maps a swap file */ struct extent_map { struct rb_node rb_node; diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index d23362f..7c2dfb2 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -6353,6 +6353,7 @@ again: else goto out; } + WARN_ON_ONCE(IS_SWAPFILE(inode)); em = alloc_extent_map(); if (!em) { err = -ENOMEM; diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h index 1faecea..5c5f9de 100644 --- a/include/trace/events/btrfs.h +++ b/include/trace/events/btrfs.h @@ -164,7 +164,8 @@ DEFINE_EVENT(btrfs__inode, btrfs_inode_evict, { (1 << EXTENT_FLAG_PREALLOC), "PREALLOC" },\ { (1 << EXTENT_FLAG_LOGGING), "LOGGING" },\ { (1 << EXTENT_FLAG_FILLING), "FILLING" },\ - { (1 << EXTENT_FLAG_FS_MAPPING), "FS_MAPPING" }) + { (1 << EXTENT_FLAG_FS_MAPPING), "FS_MAPPING" },\ + { (1 << EXTENT_FLAG_SWAPFILE), "SWAPFILE" }) TRACE_EVENT_CONDITION(btrfs_get_extent, -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
