Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / fs / efs / dir.c

diff --git a/kernel/fs/efs/dir.c b/kernel/fs/efs/dir.c
new file mode 100644 (file)
index 0000000..ce63b24
--- /dev/null
+++ b/kernel/fs/efs/dir.c
@@ -0,0 +1,103 @@
+/*
+ * dir.c
+ *
+ * Copyright (c) 1999 Al Smith
+ */
+
+#include <linux/buffer_head.h>
+#include "efs.h"
+
+static int efs_readdir(struct file *, struct dir_context *);
+
+const struct file_operations efs_dir_operations = {
+       .llseek         = generic_file_llseek,
+       .read           = generic_read_dir,
+       .iterate        = efs_readdir,
+};
+
+const struct inode_operations efs_dir_inode_operations = {
+       .lookup         = efs_lookup,
+};
+
+static int efs_readdir(struct file *file, struct dir_context *ctx)
+{
+       struct inode *inode = file_inode(file);
+       efs_block_t             block;
+       int                     slot;
+
+       if (inode->i_size & (EFS_DIRBSIZE-1))
+               pr_warn("%s(): directory size not a multiple of EFS_DIRBSIZE\n",
+                       __func__);
+
+       /* work out where this entry can be found */
+       block = ctx->pos >> EFS_DIRBSIZE_BITS;
+
+       /* each block contains at most 256 slots */
+       slot  = ctx->pos & 0xff;
+
+       /* look at all blocks */
+       while (block < inode->i_blocks) {
+               struct efs_dir          *dirblock;
+               struct buffer_head *bh;
+
+               /* read the dir block */
+               bh = sb_bread(inode->i_sb, efs_bmap(inode, block));
+
+               if (!bh) {
+                       pr_err("%s(): failed to read dir block %d\n",
+                              __func__, block);
+                       break;
+               }
+
+               dirblock = (struct efs_dir *) bh->b_data; 
+
+               if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
+                       pr_err("%s(): invalid directory block\n", __func__);
+                       brelse(bh);
+                       break;
+               }
+
+               for (; slot < dirblock->slots; slot++) {
+                       struct efs_dentry *dirslot;
+                       efs_ino_t inodenum;
+                       const char *nameptr;
+                       int namelen;
+
+                       if (dirblock->space[slot] == 0)
+                               continue;
+
+                       dirslot  = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot));
+
+                       inodenum = be32_to_cpu(dirslot->inode);
+                       namelen  = dirslot->namelen;
+                       nameptr  = dirslot->name;
+                       pr_debug("%s(): block %d slot %d/%d: inode %u, name \"%s\", namelen %u\n",
+                                __func__, block, slot, dirblock->slots-1,
+                                inodenum, nameptr, namelen);
+                       if (!namelen)
+                               continue;
+                       /* found the next entry */
+                       ctx->pos = (block << EFS_DIRBSIZE_BITS) | slot;
+
+                       /* sanity check */
+                       if (nameptr - (char *) dirblock + namelen > EFS_DIRBSIZE) {
+                               pr_warn("directory entry %d exceeds directory block\n",
+                                       slot);
+                               continue;
+                       }
+
+                       /* copy filename and data in dirslot */
+                       if (!dir_emit(ctx, nameptr, namelen, inodenum, DT_UNKNOWN)) {
+                               brelse(bh);
+                               return 0;
+                       }
+               }
+               brelse(bh);
+
+               slot = 0;
+               block++;
+       }
+       ctx->pos = (block << EFS_DIRBSIZE_BITS) | slot;
+       return 0;
+}
+