From: Hugh Dickins Date: Wed, 3 Aug 2011 23:21:24 +0000 (-0700) Subject: tmpfs: convert shmem_getpage_gfp to radix-swap X-Git-Tag: v3.1-rc1~53 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=54af60421822bb9cb664dd5cd7aac46c01ccfcf8;p=pandora-kernel.git tmpfs: convert shmem_getpage_gfp to radix-swap Convert shmem_getpage_gfp(), the engine-room of shmem, to expect page or swap entry returned from radix tree by find_lock_page(). Whereas the repetitive old method proceeded mainly under info->lock, dropping and repeating whenever one of the conditions needed was not met, now we can proceed without it, leaving shmem_add_to_page_cache() to check for a race. This way there is no need to preallocate a page, no need for an early radix_tree_preload(), no need for mem_cgroup_shmem_charge_fallback(). Move the error unwinding down to the bottom instead of repeating it throughout. ENOSPC handling is a little different from before: there is no longer any race between find_lock_page() and finding swap, but we can arrive at ENOSPC before calling shmem_recalc_inode(), which might occasionally discover freed space. Be stricter to check i_size before returning. info->lock is used for little but alloced, swapped, i_blocks updates. Move i_blocks updates out from under the max_blocks check, so even an unlimited size=0 mount can show accurate du. Signed-off-by: Hugh Dickins Acked-by: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed