From 67d9e95c393d23c229836e28b262dc73d71da784 Mon Sep 17 00:00:00 2001 From: Estelle Hammache Date: Sat, 5 Feb 2005 18:23:40 +0000 Subject: [JFFS2] Prevent deadlock during write buffer recovery Prevent deadlock when checking erased block for space allocation during wbuf recovery. Signed-off-by: Estelle Hammache Signed-off-by: Thomas Gleixner --- fs/jffs2/wbuf.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'fs/jffs2/wbuf.c') diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c index 4346940b4871..79414abadd5e 100644 --- a/fs/jffs2/wbuf.c +++ b/fs/jffs2/wbuf.c @@ -9,7 +9,7 @@ * * For licensing information, see the file 'LICENCE' in this directory. * - * $Id: wbuf.c,v 1.85 2005/02/02 22:12:04 dwmw2 Exp $ + * $Id: wbuf.c,v 1.86 2005/02/05 18:23:37 hammache Exp $ * */ @@ -865,7 +865,6 @@ int jffs2_flash_read(struct jffs2_sb_info *c, loff_t ofs, size_t len, size_t *re /* Read flash */ if (!jffs2_can_mark_obsolete(c)) { - down_read(&c->wbuf_sem); if (jffs2_cleanmarker_oob(c)) ret = c->mtd->read_ecc(c->mtd, ofs, len, retlen, buf, NULL, c->oobinfo); @@ -892,11 +891,16 @@ int jffs2_flash_read(struct jffs2_sb_info *c, loff_t ofs, size_t len, size_t *re /* if no writebuffer available or write buffer empty, return */ if (!c->wbuf_pagesize || !c->wbuf_len) - goto exit; + return ret;; /* if we read in a different block, return */ if ( (ofs & ~(c->sector_size-1)) != (c->wbuf_ofs & ~(c->sector_size-1)) ) - goto exit; + return ret; + + /* Lock only if we have reason to believe wbuf contains relevant data, + so that checking an erased block during wbuf recovery space allocation + does not deadlock. */ + down_read(&c->wbuf_sem); if (ofs >= c->wbuf_ofs) { owbf = (ofs - c->wbuf_ofs); /* offset in write buffer */ -- cgit v1.2.3-59-g8ed1b