From 4d5f5df673ee673851986b5a492a9752fbb39dc5 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Thu, 13 Feb 2014 19:40:26 +0800 Subject: [PATCH] ceph: fix __dcache_readdir() If directory is fragmented, readdir() read its dirfrags one by one. After reading all dirfrags, the corresponding dentries are sorted in (frag_t, off) order in the dcache. If dentries of a directory are all cached, __dcache_readdir() can use the cached dentries to satisfy readdir syscall. But when checking if a given dentry is after the position of readdir, __dcache_readdir() compares numerical value of frag_t directly. This is wrong, it should use ceph_frag_compare(). Signed-off-by: Yan, Zheng --- fs/ceph/dir.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index 2e3b30dcfc94..45eda6d7a40c 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -100,6 +100,14 @@ static unsigned fpos_off(loff_t p) return p & 0xffffffff; } +static int fpos_cmp(loff_t l, loff_t r) +{ + int v = ceph_frag_compare(fpos_frag(l), fpos_frag(r)); + if (v) + return v; + return (int)(fpos_off(l) - fpos_off(r)); +} + /* * When possible, we try to satisfy a readdir by peeking at the * dcache. We make this work by carefully ordering dentries on @@ -156,7 +164,7 @@ more: if (!d_unhashed(dentry) && dentry->d_inode && ceph_snap(dentry->d_inode) != CEPH_SNAPDIR && ceph_ino(dentry->d_inode) != CEPH_INO_CEPH && - ctx->pos <= di->offset) + fpos_cmp(ctx->pos, di->offset) <= 0) break; dout(" skipping %p %.*s at %llu (%llu)%s%s\n", dentry, dentry->d_name.len, dentry->d_name.name, di->offset, -- 2.20.1