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authorEstelle Hammache <estelle.hammache@st.com>2005-02-05 18:23:40 +0000
committerThomas Gleixner <tglx@mtd.linutronix.de>2005-05-23 12:23:54 +0200
commit67d9e95c393d23c229836e28b262dc73d71da784 (patch)
tree1c22b8ad2715d8155570aa082d6c20ed8c269e11 /fs/jffs2/wbuf.c
parent72b56a2d7dccd9ea90f34f6ddb653086a3f3bd2e (diff)
downloadop-kernel-dev-67d9e95c393d23c229836e28b262dc73d71da784.zip
op-kernel-dev-67d9e95c393d23c229836e28b262dc73d71da784.tar.gz
[JFFS2] Prevent deadlock during write buffer recovery
Prevent deadlock when checking erased block for space allocation during wbuf recovery. Signed-off-by: Estelle Hammache <estelle.hammache@st.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'fs/jffs2/wbuf.c')
-rw-r--r--fs/jffs2/wbuf.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c
index 4346940b4..79414ab 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 */
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