[PATCH 1/3] ufs: ufs_trunc_indirect: infinite cycle

Evgeniy Dushistov
2006-05-14T08:15:03Z

Currently, ufs write support have two sets of problems:
work with files and work with directories.

This series of patches should solve the first problem.

This patch similar to
http://lkml.org/lkml/2006/1/17/61
this patch complements it.

The situation the same: in ufs_trunc_(not direct),
we read block,
check if count of links to it is equal to one,
if so we finish cycle, if not continue.
Because of "count of links" always >=2 this operation cause
infinite cycle and hang up the kernel.

Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>

---

diff -upr -X linux-2.6.17-rc4/Documentation/dontdiff linux-2.6.17-rc4-vanilla/fs/ufs/truncate.c linux-2.6.17-rc4/fs/ufs/truncate.c
--- linux-2.6.17-rc4-vanilla/fs/ufs/truncate.c 2006-05-13 23:50:53.000000000 +0400
+++ linux-2.6.17-rc4/fs/ufs/truncate.c 2006-05-14 00:21:03.696891750 +0400
@@ -237,19 +237,14 @@ static int ufs_trunc_indirect (struct in
for (i = 0; i < uspi->s_apb; i++)
if (*ubh_get_addr32(ind_ubh,i))
break;
- if (i >= uspi->s_apb) {
- if (ubh_max_bcount(ind_ubh) != 1) {
- retry = 1;
- }
- else {
- tmp = fs32_to_cpu(sb, *p);
- *p = 0;
- inode->i_blocks -= uspi->s_nspb;
- mark_inode_dirty(inode);
- ufs_free_blocks (inode, tmp, uspi->s_fpb);
- ubh_bforget(ind_ubh);
- ind_ubh = NULL;
- }
+ if (i >= uspi->s_apb) {
+ tmp = fs32_to_cpu(sb, *p);
+ *p = 0;
+ inode->i_blocks -= uspi->s_nspb;
+ mark_inode_dirty(inode);
+ ufs_free_blocks (inode, tmp, uspi->s_fpb);
+ ubh_bforget(ind_ubh);
+ ind_ubh = NULL;
}
if (IS_SYNC(inode) && ind_ubh && ubh_buffer_dirty(ind_ubh)) {
ubh_ll_rw_block (SWRITE, 1, &ind_ubh);
@@ -305,18 +300,14 @@ static int ufs_trunc_dindirect (struct i
for (i = 0; i < uspi->s_apb; i++)
if (*ubh_get_addr32 (dind_bh, i))
break;
- if (i >= uspi->s_apb) {
- if (ubh_max_bcount(dind_bh) != 1)
- retry = 1;
- else {
- tmp = fs32_to_cpu(sb, *p);
- *p = 0;
- inode->i_blocks -= uspi->s_nspb;
- mark_inode_dirty(inode);
- ufs_free_blocks (inode, tmp, uspi->s_fpb);
- ubh_bforget(dind_bh);
- dind_bh = NULL;
- }
+ if (i >= uspi->s_apb) {
+ tmp = fs32_to_cpu(sb, *p);
+ *p = 0;
+ inode->i_blocks -= uspi->s_nspb;
+ mark_inode_dirty(inode);
+ ufs_free_blocks (inode, tmp, uspi->s_fpb);
+ ubh_bforget(dind_bh);
+ dind_bh = NULL;
}
if (IS_SYNC(inode) && dind_bh && ubh_buffer_dirty(dind_bh)) {
ubh_ll_rw_block (SWRITE, 1, &dind_bh);
@@ -369,18 +360,14 @@ static int ufs_trunc_tindirect (struct i
for (i = 0; i < uspi->s_apb; i++)
if (*ubh_get_addr32 (tind_bh, i))
break;
- if (i >= uspi->s_apb) {
- if (ubh_max_bcount(tind_bh) != 1)
- retry = 1;
- else {
- tmp = fs32_to_cpu(sb, *p);
- *p = 0;
- inode->i_blocks -= uspi->s_nspb;
- mark_inode_dirty(inode);
- ufs_free_blocks (inode, tmp, uspi->s_fpb);
- ubh_bforget(tind_bh);
- tind_bh = NULL;
- }
+ if (i >= uspi->s_apb) {
+ tmp = fs32_to_cpu(sb, *p);
+ *p = 0;
+ inode->i_blocks -= uspi->s_nspb;
+ mark_inode_dirty(inode);
+ ufs_free_blocks (inode, tmp, uspi->s_fpb);
+ ubh_bforget(tind_bh);
+ tind_bh = NULL;
}
if (IS_SYNC(inode) && tind_bh && ubh_buffer_dirty(tind_bh)) {
ubh_ll_rw_block (SWRITE, 1, &tind_bh);
diff -upr -X linux-2.6.17-rc4/Documentation/dontdiff linux-2.6.17-rc4-vanilla/fs/ufs/util.c linux-2.6.17-rc4/fs/ufs/util.c
--- linux-2.6.17-rc4-vanilla/fs/ufs/util.c 2006-05-13 23:50:53.000000000 +0400
+++ linux-2.6.17-rc4/fs/ufs/util.c 2006-05-14 00:19:07.757646000 +0400
@@ -139,18 +139,6 @@ void ubh_wait_on_buffer (struct ufs_buff
wait_on_buffer (ubh->bh[i]);
}

-unsigned ubh_max_bcount (struct ufs_buffer_head * ubh)
-{
- unsigned i;
- unsigned max = 0;
- if (!ubh)
- return 0;
- for ( i = 0; i < ubh->count; i++ )
- if ( atomic_read(&ubh->bh[i]->b_count) > max )
- max = atomic_read(&ubh->bh[i]->b_count);
- return max;
-}
-
void ubh_bforget (struct ufs_buffer_head * ubh)
{
unsigned i;
diff -upr -X linux-2.6.17-rc4/Documentation/dontdiff linux-2.6.17-rc4-vanilla/fs/ufs/util.h linux-2.6.17-rc4/fs/ufs/util.h
--- linux-2.6.17-rc4-vanilla/fs/ufs/util.h 2006-05-13 23:50:53.000000000 +0400
+++ linux-2.6.17-rc4/fs/ufs/util.h 2006-05-14 00:19:14.186047750 +0400
@@ -238,7 +238,6 @@ extern void ubh_mark_buffer_dirty (struc
extern void ubh_mark_buffer_uptodate (struct ufs_buffer_head *, int);
extern void ubh_ll_rw_block (int, unsigned, struct ufs_buffer_head **);
extern void ubh_wait_on_buffer (struct ufs_buffer_head *);
-extern unsigned ubh_max_bcount (struct ufs_buffer_head *);
extern void ubh_bforget (struct ufs_buffer_head *);
extern int ubh_buffer_dirty (struct ufs_buffer_head *);
#define ubh_ubhcpymem(mem,ubh,size) _ubh_ubhcpymem_(uspi,mem,ubh,size)

--
/Evgeniy