Commit 10e5dce0 authored by Evgeniy Dushistov's avatar Evgeniy Dushistov Committed by Linus Torvalds
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[PATCH] ufs: truncate should allocate block for last byte



This patch fixes buggy behaviour of UFS
in such kind of scenario:
open(, O_TRUNC...)
ftruncate(, 1024)
ftruncate(, 0)

Such a scenario causes ufs_panic and remount read-only.  This happen
because of according to specification UFS should always allocate block for
last byte, and many parts of our implementation rely on this, but
`ufs_truncate' doesn't care about this.

To make possible return error code and to know about old size, this patch
removes `truncate' from ufs inode_operations and uses `setattr' method to
call ufs_truncate.
Signed-off-by: default avatarEvgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent eb28931e
......@@ -217,48 +217,6 @@ failed:
return;
}
static struct page *ufs_get_locked_page(struct address_space *mapping,
unsigned long index)
{
struct page *page;
try_again:
page = find_lock_page(mapping, index);
if (!page) {
page = read_cache_page(mapping, index,
(filler_t*)mapping->a_ops->readpage,
NULL);
if (IS_ERR(page)) {
printk(KERN_ERR "ufs_change_blocknr: "
"read_cache_page error: ino %lu, index: %lu\n",
mapping->host->i_ino, index);
goto out;
}
lock_page(page);
if (!PageUptodate(page) || PageError(page)) {
unlock_page(page);
page_cache_release(page);
printk(KERN_ERR "ufs_change_blocknr: "
"can not read page: ino %lu, index: %lu\n",
mapping->host->i_ino, index);
page = ERR_PTR(-EIO);
goto out;
}
}
if (unlikely(!page->mapping || !page_has_buffers(page))) {
unlock_page(page);
page_cache_release(page);
goto try_again;/*we really need these buffers*/
}
out:
return page;
}
/*
* Modify inode page cache in such way:
* have - blocks with b_blocknr equal to oldb...oldb+count-1
......@@ -311,10 +269,8 @@ static void ufs_change_blocknr(struct inode *inode, unsigned int baseblk,
set_page_dirty(page);
if (likely(cur_index != index)) {
unlock_page(page);
page_cache_release(page);
}
if (likely(cur_index != index))
ufs_put_locked_page(page);
}
UFSD("EXIT\n");
}
......
......@@ -60,7 +60,3 @@ const struct file_operations ufs_file_operations = {
.fsync = ufs_sync_file,
.sendfile = generic_file_sendfile,
};
struct inode_operations ufs_file_inode_operations = {
.truncate = ufs_truncate,
};
......@@ -843,14 +843,17 @@ int ufs_sync_inode (struct inode *inode)
void ufs_delete_inode (struct inode * inode)
{
loff_t old_i_size;
truncate_inode_pages(&inode->i_data, 0);
/*UFS_I(inode)->i_dtime = CURRENT_TIME;*/
lock_kernel();
mark_inode_dirty(inode);
ufs_update_inode(inode, IS_SYNC(inode));
old_i_size = inode->i_size;
inode->i_size = 0;
if (inode->i_blocks)
ufs_truncate (inode);
if (inode->i_blocks && ufs_truncate(inode, old_i_size))
ufs_warning(inode->i_sb, __FUNCTION__, "ufs_truncate failed\n");
ufs_free_inode (inode);
unlock_kernel();
}
......@@ -369,24 +369,97 @@ static int ufs_trunc_tindirect (struct inode * inode)
UFSD("EXIT\n");
return retry;
}
void ufs_truncate (struct inode * inode)
static int ufs_alloc_lastblock(struct inode *inode)
{
int err = 0;
struct address_space *mapping = inode->i_mapping;
struct ufs_sb_private_info *uspi = UFS_SB(inode->i_sb)->s_uspi;
struct ufs_inode_info *ufsi = UFS_I(inode);
struct super_block * sb;
struct ufs_sb_private_info * uspi;
int retry;
unsigned lastfrag, i, end;
struct page *lastpage;
struct buffer_head *bh;
lastfrag = (i_size_read(inode) + uspi->s_fsize - 1) >> uspi->s_fshift;
if (!lastfrag) {
ufsi->i_lastfrag = 0;
goto out;
}
lastfrag--;
lastpage = ufs_get_locked_page(mapping, lastfrag >>
(PAGE_CACHE_SHIFT - inode->i_blkbits));
if (IS_ERR(lastpage)) {
err = -EIO;
goto out;
}
end = lastfrag & ((1 << (PAGE_CACHE_SHIFT - inode->i_blkbits)) - 1);
bh = page_buffers(lastpage);
for (i = 0; i < end; ++i)
bh = bh->b_this_page;
if (!buffer_mapped(bh)) {
err = ufs_getfrag_block(inode, lastfrag, bh, 1);
if (unlikely(err))
goto out_unlock;
if (buffer_new(bh)) {
clear_buffer_new(bh);
unmap_underlying_metadata(bh->b_bdev,
bh->b_blocknr);
/*
* we do not zeroize fragment, because of
* if it maped to hole, it already contains zeroes
*/
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
set_page_dirty(lastpage);
}
}
out_unlock:
ufs_put_locked_page(lastpage);
out:
return err;
}
int ufs_truncate(struct inode *inode, loff_t old_i_size)
{
struct ufs_inode_info *ufsi = UFS_I(inode);
struct super_block *sb = inode->i_sb;
struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
int retry, err = 0;
UFSD("ENTER\n");
sb = inode->i_sb;
uspi = UFS_SB(sb)->s_uspi;
if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
return;
if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
S_ISLNK(inode->i_mode)))
return -EINVAL;
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
return;
return -EPERM;
if (inode->i_size > old_i_size) {
/*
* if we expand file we should care about
* allocation of block for last byte first of all
*/
err = ufs_alloc_lastblock(inode);
if (err) {
i_size_write(inode, old_i_size);
goto out;
}
/*
* go away, because of we expand file, and we do not
* need free blocks, and zeroizes page
*/
lock_kernel();
goto almost_end;
}
block_truncate_page(inode->i_mapping, inode->i_size, ufs_getfrag_block);
block_truncate_page(inode->i_mapping, inode->i_size, ufs_getfrag_block);
lock_kernel();
while (1) {
......@@ -404,9 +477,58 @@ void ufs_truncate (struct inode * inode)
yield();
}
if (inode->i_size < old_i_size) {
/*
* now we should have enough space
* to allocate block for last byte
*/
err = ufs_alloc_lastblock(inode);
if (err)
/*
* looks like all the same - we have no space,
* but we truncate file already
*/
inode->i_size = (ufsi->i_lastfrag - 1) * uspi->s_fsize;
}
almost_end:
inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
ufsi->i_lastfrag = DIRECT_FRAGMENT;
unlock_kernel();
mark_inode_dirty(inode);
UFSD("EXIT\n");
out:
UFSD("EXIT: err %d\n", err);
return err;
}
/*
* We don't define our `inode->i_op->truncate', and call it here,
* because of:
* - there is no way to know old size
* - there is no way inform user about error, if it happens in `truncate'
*/
static int ufs_setattr(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = dentry->d_inode;
unsigned int ia_valid = attr->ia_valid;
int error;
error = inode_change_ok(inode, attr);
if (error)
return error;
if (ia_valid & ATTR_SIZE &&
attr->ia_size != i_size_read(inode)) {
loff_t old_i_size = inode->i_size;
error = vmtruncate(inode, attr->ia_size);
if (error)
return error;
error = ufs_truncate(inode, old_i_size);
if (error)
return error;
}
return inode_setattr(inode, attr);
}
struct inode_operations ufs_file_inode_operations = {
.setattr = ufs_setattr,
};
......@@ -233,3 +233,57 @@ ufs_set_inode_dev(struct super_block *sb, struct ufs_inode_info *ufsi, dev_t dev
else
ufsi->i_u1.i_data[0] = fs32;
}
/**
* ufs_get_locked_page() - locate, pin and lock a pagecache page, if not exist
* read it from disk.
* @mapping: the address_space to search
* @index: the page index
*
* Locates the desired pagecache page, if not exist we'll read it,
* locks it, increments its reference
* count and returns its address.
*
*/
struct page *ufs_get_locked_page(struct address_space *mapping,
pgoff_t index)
{
struct page *page;
try_again:
page = find_lock_page(mapping, index);
if (!page) {
page = read_cache_page(mapping, index,
(filler_t*)mapping->a_ops->readpage,
NULL);
if (IS_ERR(page)) {
printk(KERN_ERR "ufs_change_blocknr: "
"read_cache_page error: ino %lu, index: %lu\n",
mapping->host->i_ino, index);
goto out;
}
lock_page(page);
if (!PageUptodate(page) || PageError(page)) {
unlock_page(page);
page_cache_release(page);
printk(KERN_ERR "ufs_change_blocknr: "
"can not read page: ino %lu, index: %lu\n",
mapping->host->i_ino, index);
page = ERR_PTR(-EIO);
goto out;
}
}
if (unlikely(!page->mapping || !page_has_buffers(page))) {
unlock_page(page);
page_cache_release(page);
goto try_again;/*we really need these buffers*/
}
out:
return page;
}
......@@ -251,6 +251,14 @@ extern void _ubh_ubhcpymem_(struct ufs_sb_private_info *, unsigned char *, struc
#define ubh_memcpyubh(ubh,mem,size) _ubh_memcpyubh_(uspi,ubh,mem,size)
extern void _ubh_memcpyubh_(struct ufs_sb_private_info *, struct ufs_buffer_head *, unsigned char *, unsigned);
/* This functions works with cache pages*/
extern struct page *ufs_get_locked_page(struct address_space *mapping,
pgoff_t index);
static inline void ufs_put_locked_page(struct page *page)
{
unlock_page(page);
page_cache_release(page);
}
/*
......
......@@ -993,7 +993,7 @@ extern void ufs_panic (struct super_block *, const char *, const char *, ...) __
extern struct inode_operations ufs_fast_symlink_inode_operations;
/* truncate.c */
extern void ufs_truncate (struct inode *);
extern int ufs_truncate (struct inode *, loff_t);
static inline struct ufs_sb_info *UFS_SB(struct super_block *sb)
{
......
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