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Commit 2983d1bd authored by Anton Altaparmakov's avatar Anton Altaparmakov
Browse files

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



- 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: default avatarAnton Altaparmakov <aia21@cantab.net>
parent 0aacceac

fs/ntfs/ChangeLog

+6 −0
Original line number Diff line number Diff line
@@ -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...

fs/ntfs/attrib.c

+31 −1
Original line number Diff line number Diff line
@@ -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 @@ LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn, 
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);