[readdir] convert qnx4

... and use strnlen() instead of strlen() - it's done on untrusted data,
after all.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 31 insertions, 35 deletions

diff --git a/fs/qnx4/dir.c b/fs/qnx4/dir.c
index 28ce014b3cef..b218f965817b 100644
--- a/fs/qnx4/dir.c
+++ b/fs/qnx4/dir.c
@@ -14,9 +14,9 @@
 #include <linux/buffer_head.h>
 #include "qnx4.h"
 
-static int qnx4_readdir(struct file *filp, void *dirent, filldir_t filldir)
+static int qnx4_readdir(struct file *file, struct dir_context *ctx)
 {
-        struct inode *inode = file_inode(filp);
+        struct inode *inode = file_inode(file);
         unsigned int offset;
         struct buffer_head *bh;
         struct qnx4_inode_entry *de;
@@ -26,48 +26,44 @@ static int qnx4_readdir(struct file *filp, void *dirent, filldir_t filldir)
         int size;
 
         QNX4DEBUG((KERN_INFO "qnx4_readdir:i_size = %ld\n", (long) inode->i_size));
-        QNX4DEBUG((KERN_INFO "filp->f_pos         = %ld\n", (long) filp->f_pos));
+        QNX4DEBUG((KERN_INFO "pos                 = %ld\n", (long) ctx->pos));
 
-        while (filp->f_pos < inode->i_size) {
-                blknum = qnx4_block_map( inode, filp->f_pos >> QNX4_BLOCK_SIZE_BITS );
+        while (ctx->pos < inode->i_size) {
+                blknum = qnx4_block_map(inode, ctx->pos >> QNX4_BLOCK_SIZE_BITS);
                 bh = sb_bread(inode->i_sb, blknum);
-                if(bh==NULL) {
+                if (bh == NULL) {
                         printk(KERN_ERR "qnx4_readdir: bread failed (%ld)\n", blknum);
-                        break;
+                        return 0;
                 }
-                ix = (int)(filp->f_pos >> QNX4_DIR_ENTRY_SIZE_BITS) % QNX4_INODES_PER_BLOCK;
-                while (ix < QNX4_INODES_PER_BLOCK) {
+                ix = (ctx->pos >> QNX4_DIR_ENTRY_SIZE_BITS) % QNX4_INODES_PER_BLOCK;
+                for (; ix < QNX4_INODES_PER_BLOCK; ix++, ctx->pos += QNX4_DIR_ENTRY_SIZE) {
                         offset = ix * QNX4_DIR_ENTRY_SIZE;
                         de = (struct qnx4_inode_entry *) (bh->b_data + offset);
-                        size = strlen(de->di_fname);
-                        if (size) {
-                                if ( !( de->di_status & QNX4_FILE_LINK ) && size > QNX4_SHORT_NAME_MAX )
-                                        size = QNX4_SHORT_NAME_MAX;
-                                else if ( size > QNX4_NAME_MAX )
-                                        size = QNX4_NAME_MAX;
-
-                                if ( ( de->di_status & (QNX4_FILE_USED|QNX4_FILE_LINK) ) != 0 ) {
-                                        QNX4DEBUG((KERN_INFO "qnx4_readdir:%.*s\n", size, de->di_fname));
-                                        if ( ( de->di_status & QNX4_FILE_LINK ) == 0 )
-                                                ino = blknum * QNX4_INODES_PER_BLOCK + ix - 1;
-                                        else {
-                                                le  = (struct qnx4_link_info*)de;
-                                                ino = ( le32_to_cpu(le->dl_inode_blk) - 1 ) *
-                                                        QNX4_INODES_PER_BLOCK +
-                                                        le->dl_inode_ndx;
-                                        }
-                                        if (filldir(dirent, de->di_fname, size, filp->f_pos, ino, DT_UNKNOWN) < 0) {
-                                                brelse(bh);
-                                                goto out;
-                                        }
-                                }
+                        if (!de->di_fname[0])
+                                continue;
+                        if (!(de->di_status & (QNX4_FILE_USED|QNX4_FILE_LINK)))
+                                continue;
+                        if (!(de->di_status & QNX4_FILE_LINK))
+                                size = QNX4_SHORT_NAME_MAX;
+                        else
+                                size = QNX4_NAME_MAX;
+                        size = strnlen(de->di_fname, size);
+                        QNX4DEBUG((KERN_INFO "qnx4_readdir:%.*s\n", size, de->di_fname));
+                        if (!(de->di_status & QNX4_FILE_LINK))
+                                ino = blknum * QNX4_INODES_PER_BLOCK + ix - 1;
+                        else {
+                                le  = (struct qnx4_link_info*)de;
+                                ino = ( le32_to_cpu(le->dl_inode_blk) - 1 ) *
+                                        QNX4_INODES_PER_BLOCK +
+                                        le->dl_inode_ndx;
+                        }
+                        if (!dir_emit(ctx, de->di_fname, size, ino, DT_UNKNOWN)) {
+                                brelse(bh);
+                                return 0;
                         }
-                        ix++;
-                        filp->f_pos += QNX4_DIR_ENTRY_SIZE;
                 }
                 brelse(bh);
         }
-out:
         return 0;
 }
 
@@ -75,7 +71,7 @@ const struct file_operations qnx4_dir_operations =
 {
         .llseek         = generic_file_llseek,
         .read           = generic_read_dir,
-        .readdir        = qnx4_readdir,
+        .iterate        = qnx4_readdir,
         .fsync          = generic_file_fsync,
 };