[Devel] [PATCH RHEL9 COMMIT] ms/udf: Get rid of 0-length arrays in struct fileIdentDesc

[Konstantin Khorenko]

The commit is pushed to "branch-rh9-5.14.0-284.25.1.vz9.30.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh9-5.14.0-284.25.1.vz9.30.10
------>
commit 22e136e85a609313e153e652fb5513cf81cc9c49
Author: Jan Kara <jack at suse.cz>
Date:   Mon May 3 11:54:24 2021 +0200

    ms/udf: Get rid of 0-length arrays in struct fileIdentDesc
    
    Get rid of 0-length arrays in struct fileIdentDesc. This requires a bit
    of cleaning up as the second variable length array in this structure is
    often used and the code abuses the fact that the first two arrays have
    the same type and offset in struct fileIdentDesc.
    
    Signed-off-by: Jan Kara <jack at suse.cz>
    
    Getting rid of compilation warnings.
    
    https://virtuozzo.atlassian.net/browse/PSBM-148793
    
    Feature: fix ms/drivers
    
    (cherry picked from commit 979a6e28dd969a2222545001f79566b4bfaf06c0)
    Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
---
 fs/udf/dir.c      |  5 ++---
 fs/udf/ecma_167.h |  6 +++---
 fs/udf/inode.c    |  3 +--
 fs/udf/namei.c    | 13 ++++++-------
 fs/udf/udfdecl.h  |  4 ++++
 5 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/fs/udf/dir.c b/fs/udf/dir.c
index a788074a54a2..9cc1bd3a980f 100644
--- a/fs/udf/dir.c
+++ b/fs/udf/dir.c
@@ -35,7 +35,6 @@
 #include "udf_i.h"
 #include "udf_sb.h"
 
-
 static int udf_readdir(struct file *file, struct dir_context *ctx)
 {
 	struct inode *dir = file_inode(file);
@@ -135,7 +134,7 @@ static int udf_readdir(struct file *file, struct dir_context *ctx)
 		lfi = cfi.lengthFileIdent;
 
 		if (fibh.sbh == fibh.ebh) {
-			nameptr = fi->fileIdent + liu;
+			nameptr = udf_get_fi_ident(fi);
 		} else {
 			int poffset;	/* Unpaded ending offset */
 
@@ -153,7 +152,7 @@ static int udf_readdir(struct file *file, struct dir_context *ctx)
 					}
 				}
 				nameptr = copy_name;
-				memcpy(nameptr, fi->fileIdent + liu,
+				memcpy(nameptr, udf_get_fi_ident(fi),
 				       lfi - poffset);
 				memcpy(nameptr + lfi - poffset,
 				       fibh.ebh->b_data, poffset);
diff --git a/fs/udf/ecma_167.h b/fs/udf/ecma_167.h
index c6bea5c9841a..de17a97e8667 100644
--- a/fs/udf/ecma_167.h
+++ b/fs/udf/ecma_167.h
@@ -471,9 +471,9 @@ struct fileIdentDesc {
 	uint8_t		lengthFileIdent;
 	struct long_ad	icb;
 	__le16		lengthOfImpUse;
-	uint8_t		impUse[0];
-	uint8_t		fileIdent[0];
-	uint8_t		padding[0];
+	uint8_t		impUse[];
+	/* uint8_t	fileIdent[]; */
+	/* uint8_t	padding[]; */
 } __packed;
 
 /* File Characteristics (ECMA 167r3 4/14.4.3) */
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index bf6de93f1d5a..c95e3f54441c 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -390,8 +390,7 @@ struct buffer_head *udf_expand_dir_adinicb(struct inode *inode,
 		dfibh.eoffset += (sfibh.eoffset - sfibh.soffset);
 		dfi = (struct fileIdentDesc *)(dbh->b_data + dfibh.soffset);
 		if (udf_write_fi(inode, sfi, dfi, &dfibh, sfi->impUse,
-				 sfi->fileIdent +
-					le16_to_cpu(sfi->lengthOfImpUse))) {
+				 udf_get_fi_ident(sfi))) {
 			iinfo->i_alloc_type = ICBTAG_FLAG_AD_IN_ICB;
 			brelse(dbh);
 			return NULL;
diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index 7c7c9bbbfa57..caeef08efed2 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -74,12 +74,11 @@ int udf_write_fi(struct inode *inode, struct fileIdentDesc *cfi,
 
 	if (fileident) {
 		if (adinicb || (offset + lfi < 0)) {
-			memcpy((uint8_t *)sfi->fileIdent + liu, fileident, lfi);
+			memcpy(udf_get_fi_ident(sfi), fileident, lfi);
 		} else if (offset >= 0) {
 			memcpy(fibh->ebh->b_data + offset, fileident, lfi);
 		} else {
-			memcpy((uint8_t *)sfi->fileIdent + liu, fileident,
-				-offset);
+			memcpy(udf_get_fi_ident(sfi), fileident, -offset);
 			memcpy(fibh->ebh->b_data, fileident - offset,
 				lfi + offset);
 		}
@@ -88,11 +87,11 @@ int udf_write_fi(struct inode *inode, struct fileIdentDesc *cfi,
 	offset += lfi;
 
 	if (adinicb || (offset + padlen < 0)) {
-		memset((uint8_t *)sfi->padding + liu + lfi, 0x00, padlen);
+		memset(udf_get_fi_ident(sfi) + lfi, 0x00, padlen);
 	} else if (offset >= 0) {
 		memset(fibh->ebh->b_data + offset, 0x00, padlen);
 	} else {
-		memset((uint8_t *)sfi->padding + liu + lfi, 0x00, -offset);
+		memset(udf_get_fi_ident(sfi) + lfi, 0x00, -offset);
 		memset(fibh->ebh->b_data, 0x00, padlen + offset);
 	}
 
@@ -226,7 +225,7 @@ static struct fileIdentDesc *udf_find_entry(struct inode *dir,
 		lfi = cfi->lengthFileIdent;
 
 		if (fibh->sbh == fibh->ebh) {
-			nameptr = fi->fileIdent + liu;
+			nameptr = udf_get_fi_ident(fi);
 		} else {
 			int poffset;	/* Unpaded ending offset */
 
@@ -246,7 +245,7 @@ static struct fileIdentDesc *udf_find_entry(struct inode *dir,
 					}
 				}
 				nameptr = copy_name;
-				memcpy(nameptr, fi->fileIdent + liu,
+				memcpy(nameptr, udf_get_fi_ident(fi),
 					lfi - poffset);
 				memcpy(nameptr + lfi - poffset,
 					fibh->ebh->b_data, poffset);
diff --git a/fs/udf/udfdecl.h b/fs/udf/udfdecl.h
index 9dd0814f1077..7e258f15b8ef 100644
--- a/fs/udf/udfdecl.h
+++ b/fs/udf/udfdecl.h
@@ -130,6 +130,10 @@ static inline unsigned int udf_dir_entry_len(struct fileIdentDesc *cfi)
 		le16_to_cpu(cfi->lengthOfImpUse) + cfi->lengthFileIdent,
 		UDF_NAME_PAD);
 }
+static inline uint8_t *udf_get_fi_ident(struct fileIdentDesc *fi)
+{
+	return ((uint8_t *)(fi + 1)) + le16_to_cpu(fi->lengthOfImpUse);
+}
 
 /* file.c */
 extern long udf_ioctl(struct file *, unsigned int, unsigned long);