Skip to content

Commit

Permalink
[PATCH] ufs: fix hang during `rm'
Browse files Browse the repository at this point in the history 
This fixes the code like this:

	bh = sb_find_get_block (sb, tmp + j);
	if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *p)) {
		retry = 1;
		brelse (bh);
		goto next1;
	}
	bforget (bh);

sb_find_get_block() ordinarily returns a buffer_head with b_count>=2, and
this code assume that in case if "b_count>1" buffer is used, so this caused
infinite loop.

(akpm: that is-the-buffer-busy code is incomprehensible.  Good riddance.  Use
of block_truncate_page() seems sane).

Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
  • Loading branch information
@Dushistov
Dushistov authored and Linus Torvalds committed Feb 3, 2006
1 parent e295cfc commit 09114eb
Show file tree
Hide file tree
Showing 3 changed files with 18 additions and 57 deletions.
2 changes: 1 addition & 1 deletion fs/ufs/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -376,7 +376,7 @@ static struct buffer_head * ufs_block_getfrag (struct inode *inode,
* This function gets the block which contains the fragment.
*/

static int ufs_getfrag_block (struct inode *inode, sector_t fragment, struct buffer_head *bh_result, int create)
int ufs_getfrag_block (struct inode *inode, sector_t fragment, struct buffer_head *bh_result, int create)
{
struct super_block * sb = inode->i_sb;
struct ufs_sb_private_info * uspi = UFS_SB(sb)->s_uspi;
Expand Down
72 changes: 16 additions & 56 deletions fs/ufs/truncate.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -29,6 +29,11 @@
* Idea from Pierre del Perugia <delperug@gla.ecoledoc.ibp.fr>
*/

/*
* Modified to avoid infinite loop on 2006 by
* Evgeniy Dushistov <dushistov@mail.ru>
*/

#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/ufs_fs.h>
Expand Down Expand Up @@ -65,19 +70,16 @@
#define DIRECT_BLOCK ((inode->i_size + uspi->s_bsize - 1) >> uspi->s_bshift)
#define DIRECT_FRAGMENT ((inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift)

#define DATA_BUFFER_USED(bh) \
(atomic_read(&bh->b_count)>1 || buffer_locked(bh))

static int ufs_trunc_direct (struct inode * inode)
{
struct ufs_inode_info *ufsi = UFS_I(inode);
struct super_block * sb;
struct ufs_sb_private_info * uspi;
struct buffer_head * bh;
__fs32 * p;
unsigned frag1, frag2, frag3, frag4, block1, block2;
unsigned frag_to_free, free_count;
unsigned i, j, tmp;
unsigned i, tmp;
int retry;

UFSD(("ENTER\n"))
Expand Down Expand Up @@ -117,15 +119,7 @@ static int ufs_trunc_direct (struct inode * inode)
ufs_panic (sb, "ufs_trunc_direct", "internal error");
frag1 = ufs_fragnum (frag1);
frag2 = ufs_fragnum (frag2);
for (j = frag1; j < frag2; j++) {
bh = sb_find_get_block (sb, tmp + j);
if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *p)) {
retry = 1;
brelse (bh);
goto next1;
}
bforget (bh);
}

inode->i_blocks -= (frag2-frag1) << uspi->s_nspfshift;
mark_inode_dirty(inode);
ufs_free_fragments (inode, tmp + frag1, frag2 - frag1);
Expand All @@ -140,15 +134,7 @@ static int ufs_trunc_direct (struct inode * inode)
tmp = fs32_to_cpu(sb, *p);
if (!tmp)
continue;
for (j = 0; j < uspi->s_fpb; j++) {
bh = sb_find_get_block(sb, tmp + j);
if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *p)) {
retry = 1;
brelse (bh);
goto next2;
}
bforget (bh);
}

*p = 0;
inode->i_blocks -= uspi->s_nspb;
mark_inode_dirty(inode);
Expand All @@ -162,7 +148,6 @@ static int ufs_trunc_direct (struct inode * inode)
frag_to_free = tmp;
free_count = uspi->s_fpb;
}
next2:;
}

if (free_count > 0)
Expand All @@ -179,15 +164,7 @@ next2:;
if (!tmp )
ufs_panic(sb, "ufs_truncate_direct", "internal error");
frag4 = ufs_fragnum (frag4);
for (j = 0; j < frag4; j++) {
bh = sb_find_get_block (sb, tmp + j);
if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *p)) {
retry = 1;
brelse (bh);
goto next1;
}
bforget (bh);
}

*p = 0;
inode->i_blocks -= frag4 << uspi->s_nspfshift;
mark_inode_dirty(inode);
Expand All @@ -204,9 +181,8 @@ static int ufs_trunc_indirect (struct inode * inode, unsigned offset, __fs32 *p)
struct super_block * sb;
struct ufs_sb_private_info * uspi;
struct ufs_buffer_head * ind_ubh;
struct buffer_head * bh;
__fs32 * ind;
unsigned indirect_block, i, j, tmp;
unsigned indirect_block, i, tmp;
unsigned frag_to_free, free_count;
int retry;

Expand Down Expand Up @@ -238,15 +214,7 @@ static int ufs_trunc_indirect (struct inode * inode, unsigned offset, __fs32 *p)
tmp = fs32_to_cpu(sb, *ind);
if (!tmp)
continue;
for (j = 0; j < uspi->s_fpb; j++) {
bh = sb_find_get_block(sb, tmp + j);
if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *ind)) {
retry = 1;
brelse (bh);
goto next;
}
bforget (bh);
}

*ind = 0;
ubh_mark_buffer_dirty(ind_ubh);
if (free_count == 0) {
Expand All @@ -261,7 +229,6 @@ static int ufs_trunc_indirect (struct inode * inode, unsigned offset, __fs32 *p)
}
inode->i_blocks -= uspi->s_nspb;
mark_inode_dirty(inode);
next:;
}

if (free_count > 0) {
Expand Down Expand Up @@ -430,9 +397,7 @@ void ufs_truncate (struct inode * inode)
struct ufs_inode_info *ufsi = UFS_I(inode);
struct super_block * sb;
struct ufs_sb_private_info * uspi;
struct buffer_head * bh;
unsigned offset;
int err, retry;
int retry;

UFSD(("ENTER\n"))
sb = inode->i_sb;
Expand All @@ -442,6 +407,9 @@ void ufs_truncate (struct inode * inode)
return;
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
return;

block_truncate_page(inode->i_mapping, inode->i_size, ufs_getfrag_block);

lock_kernel();
while (1) {
retry = ufs_trunc_direct(inode);
Expand All @@ -457,15 +425,7 @@ void ufs_truncate (struct inode * inode)
blk_run_address_space(inode->i_mapping);
yield();
}
offset = inode->i_size & uspi->s_fshift;
if (offset) {
bh = ufs_bread (inode, inode->i_size >> uspi->s_fshift, 0, &err);
if (bh) {
memset (bh->b_data + offset, 0, uspi->s_fsize - offset);
mark_buffer_dirty (bh);
brelse (bh);
}
}

inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
ufsi->i_lastfrag = DIRECT_FRAGMENT;
unlock_kernel();
Expand Down
1 change: 1 addition & 0 deletions include/linux/ufs_fs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -912,6 +912,7 @@ extern int ufs_sync_inode (struct inode *);
extern void ufs_delete_inode (struct inode *);
extern struct buffer_head * ufs_getfrag (struct inode *, unsigned, int, int *);
extern struct buffer_head * ufs_bread (struct inode *, unsigned, int, int *);
extern int ufs_getfrag_block (struct inode *inode, sector_t fragment, struct buffer_head *bh_result, int create);

/* namei.c */
extern struct file_operations ufs_dir_operations;
Expand Down

0 comments on commit 09114eb

Please sign in to comment.