From: Dmitry Monakhov Date: Tue, 2 Dec 2014 23:08:53 +0000 (-0500) Subject: ext4: fix suboptimal seek_{data,hole} extents traversial X-Git-Tag: omap-for-v3.20/drop-legacy-3517~113^2~1 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=14516bb7bb6ffbd49f35389f9ece3b2045ba5815;p=pandora-kernel.git ext4: fix suboptimal seek_{data,hole} extents traversial It is ridiculous practice to scan inode block by block, this technique applicable only for old indirect files. This takes significant amount of time for really large files. Let's reuse ext4_fiemap which already traverse inode-tree in most optimal meaner. TESTCASE: ftruncate64(fd, 0); ftruncate64(fd, 1ULL << 40); /* lseek will spin very long time */ lseek64(fd, 0, SEEK_DATA); lseek64(fd, 0, SEEK_HOLE); Original report: https://lkml.org/lkml/2014/10/16/620 Signed-off-by: Dmitry Monakhov Signed-off-by: Theodore Ts'o --- diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index bed43081720f..e5d3eadf47b1 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -5166,8 +5166,8 @@ int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, /* fallback to generic here if not in extents fmt */ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) - return generic_block_fiemap(inode, fieinfo, start, len, - ext4_get_block); + return __generic_block_fiemap(inode, fieinfo, start, len, + ext4_get_block); if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS)) return -EBADR; Reading git-diff-tree failed