udf: Remove declarations of arrays of size UDF_NAME_LEN (256 bytes)

There are several places in UDF where we declared temporary arrays of
UDF_NAME_LEN bytes on stack. This is not nice to stack usage so this patch
changes those places to use kmalloc() instead. Also clean up bail-out paths
in those functions when we are changing them.

Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 27 insertions, 30 deletions

diff --git a/fs/udf/dir.c b/fs/udf/dir.c
index 31feef9..62dc270 100644
--- a/fs/udf/dir.c
+++ b/fs/udf/dir.c
@@ -39,13 +39,13 @@
 static int do_udf_readdir(struct inode *dir, struct file *filp,
 			  filldir_t filldir, void *dirent)
 {
-	struct udf_fileident_bh fibh;
+	struct udf_fileident_bh fibh = { .sbh = NULL, .ebh = NULL};
 	struct fileIdentDesc *fi = NULL;
 	struct fileIdentDesc cfi;
 	int block, iblock;
 	loff_t nf_pos = (filp->f_pos - 1) << 2;
 	int flen;
-	char fname[UDF_NAME_LEN];
+	char *fname = NULL;
 	char *nameptr;
 	uint16_t liu;
 	uint8_t lfi;
@@ -54,23 +54,32 @@ static int do_udf_readdir(struct inode *dir, struct file *filp,
 	kernel_lb_addr eloc;
 	uint32_t elen;
 	sector_t offset;
-	int i, num;
+	int i, num, ret = 0;
 	unsigned int dt_type;
 	struct extent_position epos = { NULL, 0, {0, 0} };
 	struct udf_inode_info *iinfo;
 
 	if (nf_pos >= size)
-		return 0;
+		goto out;
+
+	fname = kmalloc(UDF_NAME_LEN, GFP_NOFS);
+	if (!fname) {
+		ret = -ENOMEM;
+		goto out;
+	}
 
 	if (nf_pos == 0)
 		nf_pos = udf_ext0_offset(dir);
 
 	fibh.soffset = fibh.eoffset = nf_pos & (dir->i_sb->s_blocksize - 1);
 	iinfo = UDF_I(dir);
-	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
-		fibh.sbh = fibh.ebh = NULL;
-	} else if (inode_bmap(dir, nf_pos >> dir->i_sb->s_blocksize_bits,
-			      &epos, &eloc, &elen, &offset) == (EXT_RECORDED_ALLOCATED >> 30)) {
+	if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
+		if (inode_bmap(dir, nf_pos >> dir->i_sb->s_blocksize_bits,
+		    &epos, &eloc, &elen, &offset)
+		    != (EXT_RECORDED_ALLOCATED >> 30)) {
+			ret = -ENOENT;
+			goto out;
+		}
 		block = udf_get_lb_pblock(dir->i_sb, eloc, offset);
 		if ((++offset << dir->i_sb->s_blocksize_bits) < elen) {
 			if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
@@ -83,8 +92,8 @@ static int do_udf_readdir(struct inode *dir, struct file *filp,
 		}
 
 		if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block))) {
-			brelse(epos.bh);
-			return -EIO;
+			ret = -EIO;
+			goto out;
 		}
 
 		if (!(offset & ((16 >> (dir->i_sb->s_blocksize_bits - 9)) - 1))) {
@@ -105,9 +114,6 @@ static int do_udf_readdir(struct inode *dir, struct file *filp,
 					brelse(bha[i]);
 			}
 		}
-	} else {
-		brelse(epos.bh);
-		return -ENOENT;
 	}
 
 	while (nf_pos < size) {
@@ -115,13 +121,8 @@ static int do_udf_readdir(struct inode *dir, struct file *filp,
 
 		fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc,
 					&elen, &offset);
-		if (!fi) {
-			if (fibh.sbh != fibh.ebh)
-				brelse(fibh.ebh);
-			brelse(fibh.sbh);
-			brelse(epos.bh);
-			return 0;
-		}
+		if (!fi)
+			goto out;
 
 		liu = le16_to_cpu(cfi.lengthOfImpUse);
 		lfi = cfi.lengthFileIdent;
@@ -167,25 +168,21 @@ static int do_udf_readdir(struct inode *dir, struct file *filp,
 			dt_type = DT_UNKNOWN;
 		}
 
-		if (flen) {
-			if (filldir(dirent, fname, flen, filp->f_pos, iblock, dt_type) < 0) {
-				if (fibh.sbh != fibh.ebh)
-					brelse(fibh.ebh);
-				brelse(fibh.sbh);
-				brelse(epos.bh);
-	 			return 0;
-			}
-		}
+		if (flen && filldir(dirent, fname, flen, filp->f_pos,
+				    iblock, dt_type) < 0)
+			goto out;
 	} /* end while */
 
 	filp->f_pos = (nf_pos >> 2) + 1;
 
+out:
 	if (fibh.sbh != fibh.ebh)
 		brelse(fibh.ebh);
 	brelse(fibh.sbh);
 	brelse(epos.bh);
+	kfree(fname);
 
-	return 0;
+	return ret;
 }
 
 static int udf_readdir(struct file *filp, void *dirent, filldir_t filldir)