From 45b0970a0f7cfc2e6b6dbd58747e30810526dc67 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Sat, 8 Jun 2019 13:09:02 +0100 Subject: [PATCH] gfs2: Fix rounding error in gfs2_iomap_page_prepare The pos and len arguments to the iomap page_prepare callback are not block aligned, so we need to take that into account when computing the number of blocks. Fixes: 3e15f885c1cd ("gfs2: Fix iomap write page reclaim deadlock") Signed-off-by: Andreas Gruenbacher --- fs/gfs2/bmap.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index f42718dd292f4..8bae7531e883b 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -994,9 +994,12 @@ static void gfs2_write_unlock(struct inode *inode) static int gfs2_iomap_page_prepare(struct inode *inode, loff_t pos, unsigned len, struct iomap *iomap) { + unsigned int blockmask = i_blocksize(inode) - 1; struct gfs2_sbd *sdp = GFS2_SB(inode); + unsigned int blocks; - return gfs2_trans_begin(sdp, RES_DINODE + (len >> inode->i_blkbits), 0); + blocks = ((pos & blockmask) + len + blockmask) >> inode->i_blkbits; + return gfs2_trans_begin(sdp, RES_DINODE + blocks, 0); } static void gfs2_iomap_page_done(struct inode *inode, loff_t pos, -- 2.39.5