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NTFS: Fix several bugs in fs/ntfs/attrib.c.

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- Fix a bug in ntfs_map_runlist_nolock() where we forgot to protect
  access to the allocated size in the ntfs inode with the size lock.
- Fix ntfs_attr_vcn_to_lcn_nolock() and ntfs_attr_find_vcn_nolock() to
  return LCN_ENOENT when there is no runlist and the allocated size is
  zero.
- Fix load_attribute_list() to handle the case of a NULL runlist.

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
This commit is contained in:
Anton Altaparmakov 2005-09-08 20:56:09 +01:00
parent 0aacceacf3
commit 2983d1bd1a
2 changed files with 37 additions and 1 deletions
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6
fs/ntfs/ChangeLog
View File

@ -60,6 +60,12 @@ ToDo/Notes:
the index context. Thanks to Yura Pakhuchiy for finding this bug.
- Remove bogus setting of PageError in ntfs_read_compressed_block().
- Add fs/ntfs/attrib.[hc]::ntfs_resident_attr_value_resize().
- Fix a bug in ntfs_map_runlist_nolock() where we forgot to protect
access to the allocated size in the ntfs inode with the size lock.
- Fix ntfs_attr_vcn_to_lcn_nolock() and ntfs_attr_find_vcn_nolock() to
return LCN_ENOENT when there is no runlist and the allocated size is
zero.
- Fix load_attribute_list() to handle the case of a NULL runlist.
2.1.23 - Implement extension of resident files and make writing safe as well as
many bug fixes, cleanups, and enhancements...

32
fs/ntfs/attrib.c
View File

@ -43,6 +43,9 @@
* which is not an error as such. This is -ENOENT. It means that @vcn is out
* of bounds of the runlist.
*
* Note the runlist can be NULL after this function returns if @vcn is zero and
* the attribute has zero allocated size, i.e. there simply is no runlist.
*
* Locking: - The runlist must be locked for writing.
* - This function modifies the runlist.
*/
@ -54,6 +57,7 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn)
ATTR_RECORD *a;
ntfs_attr_search_ctx *ctx;
runlist_element *rl;
unsigned long flags;
int err = 0;
ntfs_debug("Mapping runlist part containing vcn 0x%llx.",
@ -85,8 +89,11 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn)
* ntfs_mapping_pairs_decompress() fails.
*/
end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn) + 1;
if (unlikely(!a->data.non_resident.lowest_vcn && end_vcn <= 1))
if (unlikely(!a->data.non_resident.lowest_vcn && end_vcn <= 1)) {
read_lock_irqsave(&ni->size_lock, flags);
end_vcn = ni->allocated_size >> ni->vol->cluster_size_bits;
read_unlock_irqrestore(&ni->size_lock, flags);
}
if (unlikely(vcn >= end_vcn)) {
err = -ENOENT;
goto err_out;
@ -165,6 +172,7 @@ LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn,
const BOOL write_locked)
{
LCN lcn;
unsigned long flags;
BOOL is_retry = FALSE;
ntfs_debug("Entering for i_ino 0x%lx, vcn 0x%llx, %s_locked.",
@ -173,6 +181,14 @@ LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn,
BUG_ON(!ni);
BUG_ON(!NInoNonResident(ni));
BUG_ON(vcn < 0);
if (!ni->runlist.rl) {
read_lock_irqsave(&ni->size_lock, flags);
if (!ni->allocated_size) {
read_unlock_irqrestore(&ni->size_lock, flags);
return LCN_ENOENT;
}
read_unlock_irqrestore(&ni->size_lock, flags);
}
retry_remap:
/* Convert vcn to lcn. If that fails map the runlist and retry once. */
lcn = ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn);
@ -255,6 +271,7 @@ retry_remap:
runlist_element *ntfs_attr_find_vcn_nolock(ntfs_inode *ni, const VCN vcn,
const BOOL write_locked)
{
unsigned long flags;
runlist_element *rl;
int err = 0;
BOOL is_retry = FALSE;
@ -265,6 +282,14 @@ runlist_element *ntfs_attr_find_vcn_nolock(ntfs_inode *ni, const VCN vcn,
BUG_ON(!ni);
BUG_ON(!NInoNonResident(ni));
BUG_ON(vcn < 0);
if (!ni->runlist.rl) {
read_lock_irqsave(&ni->size_lock, flags);
if (!ni->allocated_size) {
read_unlock_irqrestore(&ni->size_lock, flags);
return ERR_PTR(-ENOENT);
}
read_unlock_irqrestore(&ni->size_lock, flags);
}
retry_remap:
rl = ni->runlist.rl;
if (likely(rl && vcn >= rl[0].vcn)) {
@ -528,6 +553,11 @@ int load_attribute_list(ntfs_volume *vol, runlist *runlist, u8 *al_start,
block_size_bits = sb->s_blocksize_bits;
down_read(&runlist->lock);
rl = runlist->rl;
if (!rl) {
ntfs_error(sb, "Cannot read attribute list since runlist is "
"missing.");
goto err_out;
}
/* Read all clusters specified by the runlist one run at a time. */
while (rl->length) {
lcn = ntfs_rl_vcn_to_lcn(rl, rl->vcn);