[PATCH 7.2.y 1/3] ntfs: fix resident conversion in ntfs_new_attr_flags

[Sasha Levin <sashal@kernel.org>]

From: Hyunchul Lee <hyc.lee@gmail.com>

[ Upstream commit 7ed0028126b5a19f278183abbae2b3166d3ca9ac ]

When setting sparse/compressed flags on a resident attribute, the
function skipped the resident-to-non-resident conversion and
terminated.

Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Stable-dep-of: acb1095fd2db ("ntfs: fix memmove overlap in ntfs_new_attr_flags")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ntfs/ea.c | 94 ++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 72 insertions(+), 22 deletions(-)

diff --git a/fs/ntfs/ea.c b/fs/ntfs/ea.c
index 223844782fe07..7f51c261ef3e7 100644
--- a/fs/ntfs/ea.c
+++ b/fs/ntfs/ea.c
@@ -630,6 +630,7 @@ static int ntfs_new_attr_flags(struct ntfs_inode *ni, __le32 fattr)
 	struct mft_record *m;
 	struct attr_record *a;
 	__le16 new_aflags;
+	u16 old_name_ofs, old_mp_ofs;
 	int mp_size, mp_ofs, name_ofs, arec_size, err;
 
 	m = map_mft_record(ni);
@@ -662,8 +663,10 @@ static int ntfs_new_attr_flags(struct ntfs_inode *ni, __le32 fattr)
 	else
 		new_aflags &= ~ATTR_IS_COMPRESSED;
 
-	if (new_aflags == a->flags)
-		return 0;
+	if (new_aflags == a->flags) {
+		err = 0;
+		goto err_out;
+	}
 
 	if ((new_aflags & (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED)) ==
 			  (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED)) {
@@ -672,15 +675,40 @@ static int ntfs_new_attr_flags(struct ntfs_inode *ni, __le32 fattr)
 		goto err_out;
 	}
 
-	if (!a->non_resident)
-		goto out;
+	if (!a->non_resident) {
+		if (!(new_aflags & (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED)))
+			return 0;
 
-	if (a->data.non_resident.data_size) {
-		pr_err("Can't change sparsed/compressed for non-empty file\n");
-		err = -EOPNOTSUPP;
-		goto err_out;
+		if (le32_to_cpu(a->data.resident.value_length)) {
+			pr_err("Can't change sparse/compressed for non-empty file");
+			err = -EOPNOTSUPP;
+			goto err_out;
+		}
+
+		err = ntfs_attr_make_non_resident(ni, 0);
+		if (err)
+			goto err_out;
+
+		ntfs_attr_reinit_search_ctx(ctx);
+		err = ntfs_attr_lookup(ni->type, ni->name,
+				ni->name_len, CASE_SENSITIVE,
+				0, NULL, 0, ctx);
+		if (err) {
+			err = -EINVAL;
+			goto err_out;
+		}
+		a = ctx->attr;
+	} else {
+		if (a->data.non_resident.data_size) {
+			pr_err("Can't change sparsed/compressed for non-empty file");
+			err = -EOPNOTSUPP;
+			goto err_out;
+		}
 	}
 
+	old_name_ofs = le16_to_cpu(a->name_offset);
+	old_mp_ofs = le16_to_cpu(a->data.non_resident.mapping_pairs_offset);
+
 	if (new_aflags & (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED))
 		name_ofs = (offsetof(struct attr_record,
 				     data.non_resident.compressed_size) +
@@ -703,6 +731,25 @@ static int ntfs_new_attr_flags(struct ntfs_inode *ni, __le32 fattr)
 	if (unlikely(err))
 		goto err_out;
 
+	/*
+	 * When compressed/sparse state changes, the non-resident header grows or
+	 * shrinks by the compressed_size field. Update the in-record payload layout
+	 * to match the new offsets before exposing the new mapping_pairs_offset.
+	 */
+	if (name_ofs > old_name_ofs) {
+		if (mp_ofs != old_mp_ofs)
+			memmove((u8 *)a + mp_ofs, (u8 *)a + old_mp_ofs, mp_size);
+		if (a->name_length)
+			memmove((u8 *)a + name_ofs, (u8 *)a + old_name_ofs,
+				a->name_length * sizeof(__le16));
+	} else {
+		if (a->name_length && name_ofs != old_name_ofs)
+			memmove((u8 *)a + name_ofs, (u8 *)a + old_name_ofs,
+				a->name_length * sizeof(__le16));
+		if (mp_ofs != old_mp_ofs)
+			memmove((u8 *)a + mp_ofs, (u8 *)a + old_mp_ofs, mp_size);
+	}
+
 	if (new_aflags & (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED)) {
 		a->data.non_resident.compression_unit = 0;
 		if (new_aflags & ATTR_IS_COMPRESSED || ni->vol->major_ver < 3)
@@ -723,28 +770,31 @@ static int ntfs_new_attr_flags(struct ntfs_inode *ni, __le32 fattr)
 			ni->itype.compressed.block_size_bits = 0;
 			ni->itype.compressed.block_clusters = 0;
 		}
-
-		if (new_aflags & ATTR_IS_SPARSE) {
-			NInoSetSparse(ni);
-			ni->flags |= FILE_ATTR_SPARSE_FILE;
-		}
-
-		if (new_aflags & ATTR_IS_COMPRESSED) {
-			NInoSetCompressed(ni);
-			ni->flags |= FILE_ATTR_COMPRESSED;
-		}
 	} else {
-		ni->flags &= ~(FILE_ATTR_SPARSE_FILE | FILE_ATTR_COMPRESSED);
 		a->data.non_resident.compression_unit = 0;
-		NInoClearSparse(ni);
-		NInoClearCompressed(ni);
 	}
 
 	a->name_offset = cpu_to_le16(name_ofs);
 	a->data.non_resident.mapping_pairs_offset = cpu_to_le16(mp_ofs);
 
-out:
 	a->flags = new_aflags;
+
+	if (new_aflags & ATTR_IS_SPARSE) {
+		NInoSetSparse(ni);
+		ni->flags |= FILE_ATTR_SPARSE_FILE;
+	} else {
+		NInoClearSparse(ni);
+		ni->flags &= ~FILE_ATTR_SPARSE_FILE;
+	}
+
+	if (new_aflags & ATTR_IS_COMPRESSED) {
+		NInoSetCompressed(ni);
+		ni->flags |= FILE_ATTR_COMPRESSED;
+	} else {
+		NInoClearCompressed(ni);
+		ni->flags &= ~FILE_ATTR_COMPRESSED;
+	}
+
 	mark_mft_record_dirty(ctx->ntfs_ino);
 err_out:
 	if (ctx)
-- 
2.53.0