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-rw-r--r--kernel/fs/affs/dir.c142
1 files changed, 142 insertions, 0 deletions
diff --git a/kernel/fs/affs/dir.c b/kernel/fs/affs/dir.c
new file mode 100644
index 000000000..ac4f318aa
--- /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;
+}