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, 66 insertions, 62 deletions

diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index e9f587201e17..68686b79650a 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -149,7 +149,7 @@ static struct fileIdentDesc *udf_find_entry(struct inode *dir,
         struct fileIdentDesc *fi = NULL;
         loff_t f_pos;
         int block, flen;
-        char fname[UDF_NAME_LEN];
+        char *fname = NULL;
         char *nameptr;
         uint8_t lfi;
         uint16_t liu;
@@ -163,12 +163,12 @@ static struct fileIdentDesc *udf_find_entry(struct inode *dir,
         size = udf_ext0_offset(dir) + dir->i_size;
         f_pos = udf_ext0_offset(dir);
 
+        fibh->sbh = fibh->ebh = NULL;
         fibh->soffset = fibh->eoffset = f_pos & (dir->i_sb->s_blocksize - 1);
-        if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
-                fibh->sbh = fibh->ebh = NULL;
-        else if (inode_bmap(dir, f_pos >> dir->i_sb->s_blocksize_bits,
-                              &epos, &eloc, &elen, &offset) ==
-                                        (EXT_RECORDED_ALLOCATED >> 30)) {
+        if (dinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
+                if (inode_bmap(dir, f_pos >> dir->i_sb->s_blocksize_bits, &epos,
+                    &eloc, &elen, &offset) != (EXT_RECORDED_ALLOCATED >> 30))
+                        goto out_err;
                 block = udf_get_lb_pblock(dir->i_sb, eloc, offset);
                 if ((++offset << dir->i_sb->s_blocksize_bits) < elen) {
                         if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
@@ -179,25 +179,19 @@ static struct fileIdentDesc *udf_find_entry(struct inode *dir,
                         offset = 0;
 
                 fibh->sbh = fibh->ebh = udf_tread(dir->i_sb, block);
-                if (!fibh->sbh) {
-                        brelse(epos.bh);
-                        return NULL;
-                }
-        } else {
-                brelse(epos.bh);
-                return NULL;
+                if (!fibh->sbh)
+                        goto out_err;
         }
 
+        fname = kmalloc(UDF_NAME_LEN, GFP_NOFS);
+        if (!fname)
+                goto out_err;
+
         while (f_pos < size) {
                 fi = udf_fileident_read(dir, &f_pos, fibh, cfi, &epos, &eloc,
                                         &elen, &offset);
-                if (!fi) {
-                        if (fibh->sbh != fibh->ebh)
-                                brelse(fibh->ebh);
-                        brelse(fibh->sbh);
-                        brelse(epos.bh);
-                        return NULL;
-                }
+                if (!fi)
+                        goto out_err;
 
                 liu = le16_to_cpu(cfi->lengthOfImpUse);
                 lfi = cfi->lengthFileIdent;
@@ -237,18 +231,20 @@ static struct fileIdentDesc *udf_find_entry(struct inode *dir,
 
                 flen = udf_get_filename(dir->i_sb, nameptr, fname, lfi);
                 if (flen && udf_match(flen, fname, dentry->d_name.len,
-                                      dentry->d_name.name)) {
-                        brelse(epos.bh);
-                        return fi;
-                }
+                                      dentry->d_name.name))
+                        goto out_ok;
         }
 
+out_err:
+        fi = NULL;
         if (fibh->sbh != fibh->ebh)
                 brelse(fibh->ebh);
         brelse(fibh->sbh);
+out_ok:
         brelse(epos.bh);
+        kfree(fname);
 
-        return NULL;
+        return fi;
 }
 
 static struct dentry *udf_lookup(struct inode *dir, struct dentry *dentry,
@@ -303,7 +299,7 @@ static struct fileIdentDesc *udf_add_entry(struct inode *dir,
 {
         struct super_block *sb = dir->i_sb;
         struct fileIdentDesc *fi = NULL;
-        char name[UDF_NAME_LEN];
+        char *name = NULL;
         int namelen;
         loff_t f_pos;
         loff_t size = udf_ext0_offset(dir) + dir->i_size;
@@ -317,16 +313,23 @@ static struct fileIdentDesc *udf_add_entry(struct inode *dir,
         struct extent_position epos = {};
         struct udf_inode_info *dinfo;
 
+        fibh->sbh = fibh->ebh = NULL;
+        name = kmalloc(UDF_NAME_LEN, GFP_NOFS);
+        if (!name) {
+                *err = -ENOMEM;
+                goto out_err;
+        }
+
         if (dentry) {
                 if (!dentry->d_name.len) {
                         *err = -EINVAL;
-                        return NULL;
+                        goto out_err;
                 }
                 namelen = udf_put_filename(sb, dentry->d_name.name, name,
                                                  dentry->d_name.len);
                 if (!namelen) {
                         *err = -ENAMETOOLONG;
-                        return NULL;
+                        goto out_err;
                 }
         } else {
                 namelen = 0;
@@ -338,11 +341,14 @@ static struct fileIdentDesc *udf_add_entry(struct inode *dir,
 
         fibh->soffset = fibh->eoffset = f_pos & (dir->i_sb->s_blocksize - 1);
         dinfo = UDF_I(dir);
-        if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
-                fibh->sbh = fibh->ebh = NULL;
-        else if (inode_bmap(dir, f_pos >> dir->i_sb->s_blocksize_bits,
-                              &epos, &eloc, &elen, &offset) ==
-                                        (EXT_RECORDED_ALLOCATED >> 30)) {
+        if (dinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
+                if (inode_bmap(dir, f_pos >> dir->i_sb->s_blocksize_bits, &epos,
+                    &eloc, &elen, &offset) != (EXT_RECORDED_ALLOCATED >> 30)) {
+                        block = udf_get_lb_pblock(dir->i_sb,
+                                        dinfo->i_location, 0);
+                        fibh->soffset = fibh->eoffset = sb->s_blocksize;
+                        goto add;
+                }
                 block = udf_get_lb_pblock(dir->i_sb, eloc, offset);
                 if ((++offset << dir->i_sb->s_blocksize_bits) < elen) {
                         if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
@@ -354,17 +360,11 @@ static struct fileIdentDesc *udf_add_entry(struct inode *dir,
 
                 fibh->sbh = fibh->ebh = udf_tread(dir->i_sb, block);
                 if (!fibh->sbh) {
-                        brelse(epos.bh);
                         *err = -EIO;
-                        return NULL;
+                        goto out_err;
                 }
 
                 block = dinfo->i_location.logicalBlockNum;
-        } else {
-                block = udf_get_lb_pblock(dir->i_sb, dinfo->i_location, 0);
-                fibh->sbh = fibh->ebh = NULL;
-                fibh->soffset = fibh->eoffset = sb->s_blocksize;
-                goto add;
         }
 
         while (f_pos < size) {
@@ -372,12 +372,8 @@ static struct fileIdentDesc *udf_add_entry(struct inode *dir,
                                         &elen, &offset);
 
                 if (!fi) {
-                        if (fibh->sbh != fibh->ebh)
-                                brelse(fibh->ebh);
-                        brelse(fibh->sbh);
-                        brelse(epos.bh);
                         *err = -EIO;
-                        return NULL;
+                        goto out_err;
                 }
 
                 liu = le16_to_cpu(cfi->lengthOfImpUse);
@@ -386,7 +382,6 @@ static struct fileIdentDesc *udf_add_entry(struct inode *dir,
                 if ((cfi->fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) {
                         if (((sizeof(struct fileIdentDesc) +
                                         liu + lfi + 3) & ~3) == nfidlen) {
-                                brelse(epos.bh);
                                 cfi->descTag.tagSerialNum = cpu_to_le16(1);
                                 cfi->fileVersionNum = cpu_to_le16(1);
                                 cfi->fileCharacteristics = 0;
@@ -394,10 +389,10 @@ static struct fileIdentDesc *udf_add_entry(struct inode *dir,
                                 cfi->lengthOfImpUse = cpu_to_le16(0);
                                 if (!udf_write_fi(dir, cfi, fi, fibh, NULL,
                                                   name))
-                                        return fi;
+                                        goto out_ok;
                                 else {
                                         *err = -EIO;
-                                        return NULL;
+                                        goto out_err;
                                 }
                         }
                 }
@@ -427,7 +422,7 @@ add:
                 fibh->sbh = fibh->ebh =
                                 udf_expand_dir_adinicb(dir, &block, err);
                 if (!fibh->sbh)
-                        return NULL;
+                        goto out_err;
                 epos.block = dinfo->i_location;
                 epos.offset = udf_file_entry_alloc_offset(dir);
                 /* Load extent udf_expand_dir_adinicb() has created */
@@ -468,11 +463,8 @@ add:
                                                 dir->i_sb->s_blocksize_bits);
                 fibh->ebh = udf_bread(dir,
                                 f_pos >> dir->i_sb->s_blocksize_bits, 1, err);
-                if (!fibh->ebh) {
-                        brelse(epos.bh);
-                        brelse(fibh->sbh);
-                        return NULL;
-                }
+                if (!fibh->ebh)
+                        goto out_err;
 
                 if (!fibh->soffset) {
                         if (udf_next_aext(dir, &epos, &eloc, &elen, 1) ==
@@ -503,20 +495,25 @@ add:
         cfi->lengthFileIdent = namelen;
         cfi->lengthOfImpUse = cpu_to_le16(0);
         if (!udf_write_fi(dir, cfi, fi, fibh, NULL, name)) {
-                brelse(epos.bh);
                 dir->i_size += nfidlen;
                 if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
                         dinfo->i_lenAlloc += nfidlen;
                 mark_inode_dirty(dir);
-                return fi;
+                goto out_ok;
         } else {
-                brelse(epos.bh);
-                if (fibh->sbh != fibh->ebh)
-                        brelse(fibh->ebh);
-                brelse(fibh->sbh);
                 *err = -EIO;
-                return NULL;
+                goto out_err;
         }
+
+out_err:
+        fi = NULL;
+        if (fibh->sbh != fibh->ebh)
+                brelse(fibh->ebh);
+        brelse(fibh->sbh);
+out_ok:
+        brelse(epos.bh);
+        kfree(name);
+        return fi;
 }
 
 static int udf_delete_entry(struct inode *inode, struct fileIdentDesc *fi,
@@ -871,7 +868,7 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry,
         char *ea;
         int err;
         int block;
-        char name[UDF_NAME_LEN];
+        char *name = NULL;
         int namelen;
         struct buffer_head *bh;
         struct udf_inode_info *iinfo;
@@ -881,6 +878,12 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry,
         if (!inode)
                 goto out;
 
+        name = kmalloc(UDF_NAME_LEN, GFP_NOFS);
+        if (!name) {
+                err = -ENOMEM;
+                goto out_no_entry;
+        }
+
         iinfo = UDF_I(inode);
         inode->i_mode = S_IFLNK | S_IRWXUGO;
         inode->i_data.a_ops = &udf_symlink_aops;
@@ -1020,6 +1023,7 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry,
         err = 0;
 
 out:
+        kfree(name);
         unlock_kernel();
         return err;