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Commit c0c1cc0e authored by Anton Altaparmakov's avatar Anton Altaparmakov
Browse files

NTFS: - Fix bug in fs/ntfs/attrib.c::ntfs_find_vcn_nolock() where after 


        dropping the read lock and taking the write lock we were not checking
        whether someone else did not already do the work we wanted to do.
      - Rename ntfs_find_vcn_nolock() to ntfs_attr_find_vcn_nolock().
      - Tidy up some comments in fs/ntfs/runlist.c.
      - Add LCN_ENOMEM and LCN_EIO definitions to fs/ntfs/runlist.h.

Signed-off-by: default avatarAnton Altaparmakov <aia21@cantab.net>
parent 271849a9

fs/ntfs/ChangeLog

+5 −0
Original line number Diff line number Diff line
@@ -92,6 +92,11 @@ ToDo/Notes: 
	  non-resident in fs/ntfs/attrib.c::ntfs_attr_can_be_non_resident().

	- Add fs/ntfs/attrib.c::ntfs_attr_vcn_to_lcn_nolock() used by the new

	  write code.

	- Fix bug in fs/ntfs/attrib.c::ntfs_find_vcn_nolock() where after

	  dropping the read lock and taking the write lock we were not checking

	  whether someone else did not already do the work we wanted to do.

	- Rename fs/ntfs/attrib.c::ntfs_find_vcn_nolock() to

	  ntfs_attr_find_vcn_nolock() and update all callers.



2.1.22 - Many bug and race fixes and error handling improvements.

fs/ntfs/attrib.c

+17 −12
Original line number Diff line number Diff line
@@ -193,19 +193,19 @@ LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn, 
}



/**

 * ntfs_find_vcn_nolock - find a vcn in the runlist described by an ntfs inode

 * ntfs_attr_find_vcn_nolock - find a vcn in the runlist of an ntfs inode

 * @ni:			ntfs inode describing the runlist to search

 * @vcn:		vcn to find

 * @write_locked:	true if the runlist is locked for writing

 *

 * Find the virtual cluster number @vcn in the runlist described by the ntfs

 * inode @ni and return the address of the runlist element containing the @vcn.

 * The runlist is left locked and the caller has to unlock it.  In the error

 * case, the runlist is left in the same locking state as on entry.

 *

 * Note if @write_locked is FALSE the lock may be dropped inside the function

 * so you cannot rely on the runlist still being the same when this function

 * returns.

 * If the @vcn is not mapped yet, the attempt is made to map the attribute

 * extent containing the @vcn and the vcn to lcn conversion is retried.

 *

 * If @write_locked is true the caller has locked the runlist for writing and

 * if false for reading.

 *

 * Note you need to distinguish between the lcn of the returned runlist element

 * being >= 0 and LCN_HOLE.  In the later case you have to return zeroes on
@@ -221,13 +221,12 @@ LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn, 
 *	-ENOMEM - Not enough memory to map runlist.

 *	-EIO	- Critical error (runlist/file is corrupt, i/o error, etc).

 *

 * Locking: - The runlist must be unlocked on entry.

 *	    - On failing return, the runlist is unlocked.

 *	    - On successful return, the runlist is locked.  If @need_write us

 *	      true, it is locked for writing.  Otherwise is is locked for

 *	      reading.

 * Locking: - The runlist must be locked on entry and is left locked on return.

 *	    - If @write_locked is FALSE, i.e. the runlist is locked for reading,

 *	      the lock may be dropped inside the function so you cannot rely on

 *	      the runlist still being the same when this function returns.

 */

runlist_element *ntfs_find_vcn_nolock(ntfs_inode *ni, const VCN vcn,

runlist_element *ntfs_attr_find_vcn_nolock(ntfs_inode *ni, const VCN vcn,

		const BOOL write_locked)

{

	runlist_element *rl;
@@ -268,6 +267,12 @@ runlist_element *ntfs_find_vcn_nolock(ntfs_inode *ni, const VCN vcn, 
		if (!write_locked) {

			up_read(&ni->runlist.lock);

			down_write(&ni->runlist.lock);

			if (unlikely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) !=

					LCN_RL_NOT_MAPPED)) {

				up_write(&ni->runlist.lock);

				down_read(&ni->runlist.lock);

				goto retry_remap;

			}

		}

		err = ntfs_map_runlist_nolock(ni, vcn);

		if (!write_locked) {

fs/ntfs/attrib.h

+2 −2
Original line number Diff line number Diff line
@@ -66,8 +66,8 @@ extern int ntfs_map_runlist(ntfs_inode *ni, VCN vcn); 
extern LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn,

		const BOOL write_locked);



extern runlist_element *ntfs_find_vcn_nolock(ntfs_inode *ni, const VCN vcn,

		const BOOL write_locked);

extern runlist_element *ntfs_attr_find_vcn_nolock(ntfs_inode *ni,

		const VCN vcn, const BOOL write_locked);



int ntfs_attr_lookup(const ATTR_TYPE type, const ntfschar *name,

		const u32 name_len, const IGNORE_CASE_BOOL ic,

fs/ntfs/lcnalloc.c

+2 −2
Original line number Diff line number Diff line
@@ -850,7 +850,7 @@ s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn, s64 count, 


	/* This returns with ni->runlist locked for reading on success. */

	down_read(&ni->runlist.lock);

	rl = ntfs_find_vcn_nolock(ni, start_vcn, FALSE);

	rl = ntfs_attr_find_vcn_nolock(ni, start_vcn, FALSE);

	if (IS_ERR(rl)) {

		if (!is_rollback)

			ntfs_error(vol->sb, "Failed to find first runlist "
@@ -904,7 +904,7 @@ s64 __ntfs_cluster_free(struct inode *vi, const VCN start_vcn, s64 count, 


			/* Attempt to map runlist. */

			vcn = rl->vcn;

			rl = ntfs_find_vcn_nolock(ni, vcn, FALSE);

			rl = ntfs_attr_find_vcn_nolock(ni, vcn, FALSE);

			if (IS_ERR(rl)) {

				err = PTR_ERR(rl);

				if (!is_rollback)

fs/ntfs/mft.c

+3 −3
Original line number Diff line number Diff line
@@ -1297,7 +1297,7 @@ static int ntfs_mft_bitmap_extend_allocation_nolock(ntfs_volume *vol) 
	read_lock_irqsave(&mftbmp_ni->size_lock, flags);

	ll = mftbmp_ni->allocated_size;

	read_unlock_irqrestore(&mftbmp_ni->size_lock, flags);

	rl = ntfs_find_vcn_nolock(mftbmp_ni,

	rl = ntfs_attr_find_vcn_nolock(mftbmp_ni,

			(ll - 1) >> vol->cluster_size_bits, TRUE);

	if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) {

		up_write(&mftbmp_ni->runlist.lock);
@@ -1727,8 +1727,8 @@ static int ntfs_mft_data_extend_allocation_nolock(ntfs_volume *vol) 
	read_lock_irqsave(&mft_ni->size_lock, flags);

	ll = mft_ni->allocated_size;

	read_unlock_irqrestore(&mft_ni->size_lock, flags);

	rl = ntfs_find_vcn_nolock(mft_ni, (ll - 1) >> vol->cluster_size_bits,

			TRUE);

	rl = ntfs_attr_find_vcn_nolock(mft_ni,

			(ll - 1) >> vol->cluster_size_bits, TRUE);

	if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) {

		up_write(&mft_ni->runlist.lock);

		ntfs_error(vol->sb, "Failed to determine last allocated "