Add the rt linux 4.1.3-rt3 as base

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

diff --git a/kernel/fs/affs/dir.c b/kernel/fs/affs/dir.c
new file mode 100644 (file)
index 0000000..ac4f318
--- /dev/null
+++ b/kernel/fs/affs/dir.c
@@ -0,0 +1,142 @@
+/*
+ *  linux/fs/affs/dir.c
+ *
+ *  (c) 1996  Hans-Joachim Widmaier - Rewritten
+ *
+ *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
+ *
+ *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
+ *
+ *  (C) 1991  Linus Torvalds - minix filesystem
+ *
+ *  affs directory handling functions
+ *
+ */
+
+#include "affs.h"
+
+static int affs_readdir(struct file *, struct dir_context *);
+
+const struct file_operations affs_dir_operations = {
+       .read           = generic_read_dir,
+       .llseek         = generic_file_llseek,
+       .iterate        = affs_readdir,
+       .fsync          = affs_file_fsync,
+};
+
+/*
+ * directories can handle most operations...
+ */
+const struct inode_operations affs_dir_inode_operations = {
+       .create         = affs_create,
+       .lookup         = affs_lookup,
+       .link           = affs_link,
+       .unlink         = affs_unlink,
+       .symlink        = affs_symlink,
+       .mkdir          = affs_mkdir,
+       .rmdir          = affs_rmdir,
+       .rename         = affs_rename,
+       .setattr        = affs_notify_change,
+};
+
+static int
+affs_readdir(struct file *file, struct dir_context *ctx)
+{
+       struct inode            *inode = file_inode(file);
+       struct super_block      *sb = inode->i_sb;
+       struct buffer_head      *dir_bh = NULL;
+       struct buffer_head      *fh_bh = NULL;
+       unsigned char           *name;
+       int                      namelen;
+       u32                      i;
+       int                      hash_pos;
+       int                      chain_pos;
+       u32                      ino;
+       int                      error = 0;
+
+       pr_debug("%s(ino=%lu,f_pos=%llx)\n", __func__, inode->i_ino, ctx->pos);
+
+       if (ctx->pos < 2) {
+               file->private_data = (void *)0;
+               if (!dir_emit_dots(file, ctx))
+                       return 0;
+       }
+
+       affs_lock_dir(inode);
+       chain_pos = (ctx->pos - 2) & 0xffff;
+       hash_pos  = (ctx->pos - 2) >> 16;
+       if (chain_pos == 0xffff) {
+               affs_warning(sb, "readdir", "More than 65535 entries in chain");
+               chain_pos = 0;
+               hash_pos++;
+               ctx->pos = ((hash_pos << 16) | chain_pos) + 2;
+       }
+       dir_bh = affs_bread(sb, inode->i_ino);
+       if (!dir_bh)
+               goto out_unlock_dir;
+
+       /* If the directory hasn't changed since the last call to readdir(),
+        * we can jump directly to where we left off.
+        */
+       ino = (u32)(long)file->private_data;
+       if (ino && file->f_version == inode->i_version) {
+               pr_debug("readdir() left off=%d\n", ino);
+               goto inside;
+       }
+
+       ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
+       for (i = 0; ino && i < chain_pos; i++) {
+               fh_bh = affs_bread(sb, ino);
+               if (!fh_bh) {
+                       affs_error(sb, "readdir","Cannot read block %d", i);
+                       error = -EIO;
+                       goto out_brelse_dir;
+               }
+               ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
+               affs_brelse(fh_bh);
+               fh_bh = NULL;
+       }
+       if (ino)
+               goto inside;
+       hash_pos++;
+
+       for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) {
+               ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
+               if (!ino)
+                       continue;
+               ctx->pos = (hash_pos << 16) + 2;
+inside:
+               do {
+                       fh_bh = affs_bread(sb, ino);
+                       if (!fh_bh) {
+                               affs_error(sb, "readdir",
+                                          "Cannot read block %d", ino);
+                               break;
+                       }
+
+                       namelen = min(AFFS_TAIL(sb, fh_bh)->name[0],
+                                     (u8)AFFSNAMEMAX);
+                       name = AFFS_TAIL(sb, fh_bh)->name + 1;
+                       pr_debug("readdir(): dir_emit(\"%.*s\", ino=%u), hash=%d, f_pos=%llx\n",
+                                namelen, name, ino, hash_pos, ctx->pos);
+
+                       if (!dir_emit(ctx, name, namelen, ino, DT_UNKNOWN))
+                               goto done;
+                       ctx->pos++;
+                       ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
+                       affs_brelse(fh_bh);
+                       fh_bh = NULL;
+               } while (ino);
+       }
+done:
+       file->f_version = inode->i_version;
+       file->private_data = (void *)(long)ino;
+       affs_brelse(fh_bh);
+
+out_brelse_dir:
+       affs_brelse(dir_bh);
+
+out_unlock_dir:
+       affs_unlock_dir(inode);
+       return error;
+}