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From: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
To: <ntfs3@lists.linux.dev>
CC: <linux-kernel@vger.kernel.org>, <linux-fsdevel@vger.kernel.org>,
	Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Subject: [PATCH 03/18] fs/ntfs3: Fix transform resident to nonresident for compressed files
Date: Fri, 7 Jun 2024 15:15:33 +0300
Message-ID: <20240607121548.18818-4-almaz.alexandrovich@paragon-software.com>
In-Reply-To: <20240607121548.18818-1-almaz.alexandrovich@paragon-software.com>
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Сorrected calculation of required space len (in clusters)
for attribute data storage in case of compression.

Fixes: be71b5cba2e64 ("fs/ntfs3: Add attrib operations")
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
---
 fs/ntfs3/attrib.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/fs/ntfs3/attrib.c b/fs/ntfs3/attrib.c
index 8e6bcdf99770..8638248d80d9 100644
--- a/fs/ntfs3/attrib.c
+++ b/fs/ntfs3/attrib.c
@@ -231,7 +231,7 @@ int attr_make_nonresident(struct ntfs_inode *ni, struct ATTRIB *attr,
 	struct ntfs_sb_info *sbi;
 	struct ATTRIB *attr_s;
 	struct MFT_REC *rec;
-	u32 used, asize, rsize, aoff, align;
+	u32 used, asize, rsize, aoff;
 	bool is_data;
 	CLST len, alen;
 	char *next;
@@ -252,10 +252,13 @@ int attr_make_nonresident(struct ntfs_inode *ni, struct ATTRIB *attr,
 	rsize = le32_to_cpu(attr->res.data_size);
 	is_data = attr->type == ATTR_DATA && !attr->name_len;
 
-	align = sbi->cluster_size;
-	if (is_attr_compressed(attr))
-		align <<= COMPRESSION_UNIT;
-	len = (rsize + align - 1) >> sbi->cluster_bits;
+	/* len - how many clusters required to store 'rsize' bytes */
+	if (is_attr_compressed(attr)) {
+		u8 shift = sbi->cluster_bits + NTFS_LZNT_CUNIT;
+		len = ((rsize + (1u << shift) - 1) >> shift) << NTFS_LZNT_CUNIT;
+	} else {
+		len = bytes_to_cluster(sbi, rsize);
+	}
 
 	run_init(run);
 
-- 
2.34.1