Commit 90bb7ab0 authored by Barry Naujok's avatar Barry Naujok Committed by Niv Sardi
Browse files

[XFS] Fix returning case-preserved name with CI node form directories 



xfs_dir2_node_lookup() calls xfs_da_node_lookup_int() which iterates
through leaf blocks containing the matching hash value for the name being
looked up. Inside xfs_da_node_lookup_int(), it calls the
xfs_dir2_leafn_lookup_for_entry() for each leaf block.
xfs_dir2_leafn_lookup_for_entry() iterates through each matching
hash/offset pair doing a name comparison to find the matching dirent.

For CI mode, the state->extrablk retains the details of the block that has
the CI match so xfs_dir2_node_lookup() can return the case-preserved name.

The original implementation didn't retain the xfs_da_buf_t properly, so
the lookup was returning a bogus name to be stored in the dentry.

In the case of unlink, the bad name was passed and in debug mode, ASSERTed
when it can't find the entry.

SGI-PV: 983284

SGI-Modid: xfs-linux-melb:xfs-kern:31337a

Signed-off-by: default avatarBarry Naujok <bnaujok@sgi.com>
Signed-off-by: default avatarChristoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarLachlan McIlroy <lachlan@sgi.com>
parent e5700704

fs/xfs/xfs_dir2_node.c

+43 −26
Original line number Diff line number Diff line
@@ -549,7 +549,6 @@ xfs_dir2_leafn_lookup_for_entry( 
	xfs_dir2_data_entry_t	*dep;		/* data block entry */

	xfs_inode_t		*dp;		/* incore directory inode */

	int			error;		/* error return value */

	int			di = -1;	/* data entry index */

	int			index;		/* leaf entry index */

	xfs_dir2_leaf_t		*leaf;		/* leaf structure */

	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry */
@@ -577,7 +576,6 @@ xfs_dir2_leafn_lookup_for_entry( 
	if (state->extravalid) {

		curbp = state->extrablk.bp;

		curdb = state->extrablk.blkno;

		di = state->extrablk.index;

	}

	/*

	 * Loop over leaf entries with the right hash value.
@@ -602,17 +600,27 @@ xfs_dir2_leafn_lookup_for_entry( 
		 */

		if (newdb != curdb) {

			/*

			 * If we had a block before, drop it.

			 * If we had a block before that we aren't saving

			 * for a CI name, drop it

			 */

			if (curbp)

			if (curbp && (args->cmpresult == XFS_CMP_DIFFERENT ||

						curdb != state->extrablk.blkno))

				xfs_da_brelse(tp, curbp);

			/*

			 * Read the data block.

			 * If needing the block that is saved with a CI match,

			 * use it otherwise read in the new data block.

			 */

			error = xfs_da_read_buf(tp, dp, xfs_dir2_db_to_da(mp,

					newdb), -1, &curbp, XFS_DATA_FORK);

			if (args->cmpresult != XFS_CMP_DIFFERENT &&

					newdb == state->extrablk.blkno) {

				ASSERT(state->extravalid);

				curbp = state->extrablk.bp;

			} else {

				error = xfs_da_read_buf(tp, dp,

						xfs_dir2_db_to_da(mp, newdb),

						-1, &curbp, XFS_DATA_FORK);

				if (error)

					return error;

			}

			xfs_dir2_data_check(dp, curbp);

			curdb = newdb;

		}
@@ -624,38 +632,47 @@ xfs_dir2_leafn_lookup_for_entry( 
		/*

		 * Compare the entry and if it's an exact match, return

		 * EEXIST immediately. If it's the first case-insensitive

		 * match, store the inode number and continue looking.

		 * match, store the block & inode number and continue looking.

		 */

		cmp = mp->m_dirnameops->compname(args, dep->name, dep->namelen);

		if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {

			/* If there is a CI match block, drop it */

			if (args->cmpresult != XFS_CMP_DIFFERENT &&

						curdb != state->extrablk.blkno)

				xfs_da_brelse(tp, state->extrablk.bp);

			args->cmpresult = cmp;

			args->inumber = be64_to_cpu(dep->inumber);

			di = (int)((char *)dep - (char *)curbp->data);

			error = EEXIST;

			*indexp = index;

			state->extravalid = 1;

			state->extrablk.bp = curbp;

			state->extrablk.blkno = curdb;

			state->extrablk.index = (int)((char *)dep -

							(char *)curbp->data);

			state->extrablk.magic = XFS_DIR2_DATA_MAGIC;

			if (cmp == XFS_CMP_EXACT)

				goto out;

				return XFS_ERROR(EEXIST);

		}

	}

	/* Didn't find an exact match. */

	error = ENOENT;

	ASSERT(index == be16_to_cpu(leaf->hdr.count) ||

					(args->op_flags & XFS_DA_OP_OKNOENT));

out:

	if (curbp) {

		/* Giving back a data block. */

		if (args->cmpresult == XFS_CMP_DIFFERENT) {

			/* Giving back last used data block. */

			state->extravalid = 1;

			state->extrablk.bp = curbp;

		state->extrablk.index = di;

			state->extrablk.index = -1;

			state->extrablk.blkno = curdb;

			state->extrablk.magic = XFS_DIR2_DATA_MAGIC;

		} else {

			/* If the curbp is not the CI match block, drop it */

			if (state->extrablk.bp != curbp)

				xfs_da_brelse(tp, curbp);

		}

	} else {

		state->extravalid = 0;

	}

	/*

	 * Return the index, that will be the deletion point for remove/replace.

	 */

	*indexp = index;

	return XFS_ERROR(error);

	return XFS_ERROR(ENOENT);

}



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