patch-2.4.1 linux/fs/reiserfs/dir.c

• Lines: 250
• Date: Mon Jan 15 15:31:19 2001
• Orig file: v2.4.0/linux/fs/reiserfs/dir.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.0/linux/fs/reiserfs/dir.c linux/fs/reiserfs/dir.c
@@ -0,0 +1,249 @@
+/*
+ * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
+ */
+
+#ifdef __KERNEL__
+
+#include <linux/config.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/reiserfs_fs.h>
+#include <linux/stat.h>
+#include <linux/smp_lock.h>
+#include <asm/uaccess.h>
+
+#else
+
+#include "nokernel.h"
+
+#endif
+
+extern struct key  MIN_KEY;
+
+static int reiserfs_readdir (struct file *, void *, filldir_t);
+int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry, int datasync) ;
+
+struct file_operations reiserfs_dir_operations = {
+    read:	generic_read_dir,
+    readdir:	reiserfs_readdir,
+    fsync:	reiserfs_dir_fsync,
+};
+
+/*
+ * directories can handle most operations...
+ */
+struct inode_operations reiserfs_dir_inode_operations = {
+  //&reiserfs_dir_operations,	/* default_file_ops */
+    create:	reiserfs_create,
+    lookup:	reiserfs_lookup,
+    link:	reiserfs_link,
+    unlink:	reiserfs_unlink,
+    symlink:	reiserfs_symlink,
+    mkdir:	reiserfs_mkdir,
+    rmdir:	reiserfs_rmdir,
+    mknod:	reiserfs_mknod,
+    rename:	reiserfs_rename,
+};
+
+int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry, int datasync) {
+  int ret = 0 ;
+  int windex ;
+  struct reiserfs_transaction_handle th ;
+
+  journal_begin(&th, dentry->d_inode->i_sb, 1) ;
+  windex = push_journal_writer("dir_fsync") ;
+  reiserfs_prepare_for_journal(th.t_super, SB_BUFFER_WITH_SB(th.t_super), 1) ;
+  journal_mark_dirty(&th, dentry->d_inode->i_sb, SB_BUFFER_WITH_SB (dentry->d_inode->i_sb)) ;
+  pop_journal_writer(windex) ;
+  journal_end_sync(&th, dentry->d_inode->i_sb, 1) ;
+
+  return ret ;
+}
+
+
+#define store_ih(where,what) copy_item_head (where, what)
+
+//
+static int reiserfs_readdir (struct file * filp, void * dirent, filldir_t filldir)
+{
+    struct inode *inode = filp->f_dentry->d_inode;
+    struct cpu_key pos_key;	/* key of current position in the directory (key of directory entry) */
+    INITIALIZE_PATH (path_to_entry);
+    struct buffer_head * bh;
+    int item_num, entry_num;
+    struct key * rkey;
+    struct item_head * ih, tmp_ih;
+    int search_res;
+    char * local_buf;
+    loff_t next_pos;
+    char small_buf[32] ; /* avoid kmalloc if we can */
+    struct reiserfs_dir_entry de;
+
+
+    reiserfs_check_lock_depth("readdir") ;
+
+    /* form key for search the next directory entry using f_pos field of
+       file structure */
+    make_cpu_key (&pos_key, inode, (filp->f_pos) ? (filp->f_pos) : DOT_OFFSET,
+		  TYPE_DIRENTRY, 3);
+    next_pos = cpu_key_k_offset (&pos_key);
+
+    /*  reiserfs_warning ("reiserfs_readdir 1: f_pos = %Ld\n", filp->f_pos);*/
+
+    while (1) {
+    research:
+	/* search the directory item, containing entry with specified key */
+	search_res = search_by_entry_key (inode->i_sb, &pos_key, &path_to_entry, &de);
+	if (search_res == IO_ERROR) {
+	    // FIXME: we could just skip part of directory which could
+	    // not be read
+	    return -EIO;
+	}
+	entry_num = de.de_entry_num;
+	bh = de.de_bh;
+	item_num = de.de_item_num;
+	ih = de.de_ih;
+	store_ih (&tmp_ih, ih);
+		
+#ifdef CONFIG_REISERFS_CHECK
+	/* we must have found item, that is item of this directory, */
+	if (COMP_SHORT_KEYS (&(ih->ih_key), &pos_key))
+	    reiserfs_panic (inode->i_sb, "vs-9000: reiserfs_readdir: "
+			    "found item %h does not match to dir we readdir %k",
+			    ih, &pos_key);
+      
+	if (item_num > B_NR_ITEMS (bh) - 1)
+	    reiserfs_panic (inode->i_sb, "vs-9005: reiserfs_readdir: "
+			    "item_num == %d, item amount == %d",
+			    item_num, B_NR_ITEMS (bh));
+      
+	/* and entry must be not more than number of entries in the item */
+	if (I_ENTRY_COUNT (ih) < entry_num)
+	    reiserfs_panic (inode->i_sb, "vs-9010: reiserfs_readdir: "
+			    "entry number is too big %d (%d)",
+			    entry_num, I_ENTRY_COUNT (ih));
+#endif	/* CONFIG_REISERFS_CHECK */
+
+	if (search_res == POSITION_FOUND || entry_num < I_ENTRY_COUNT (ih)) {
+	    /* go through all entries in the directory item beginning from the entry, that has been found */
+	    struct reiserfs_de_head * deh = B_I_DEH (bh, ih) + entry_num;
+
+	    for (; entry_num < I_ENTRY_COUNT (ih); entry_num ++, deh ++) {
+		int d_reclen;
+		char * d_name;
+		off_t d_off;
+		ino_t d_ino;
+
+		if (!de_visible (deh))
+		    /* it is hidden entry */
+		    continue;
+		d_reclen = entry_length (bh, ih, entry_num);
+		d_name = B_I_DEH_ENTRY_FILE_NAME (bh, ih, deh);
+		if (!d_name[d_reclen - 1])
+		    d_reclen = strlen (d_name);
+	
+		if (d_reclen > REISERFS_MAX_NAME_LEN(inode->i_sb->s_blocksize)){
+		    /* too big to send back to VFS */
+		    continue ;
+		}
+		d_off = deh_offset (deh);
+		filp->f_pos = d_off ;
+		d_ino = deh_objectid (deh);
+		if (d_reclen <= 32) {
+		  local_buf = small_buf ;
+		} else {
+		    local_buf = kmalloc(d_reclen, GFP_BUFFER) ;
+		    if (!local_buf) {
+			pathrelse (&path_to_entry);
+			return -ENOMEM ;
+		    }
+		    if (item_moved (&tmp_ih, &path_to_entry)) {
+			kfree(local_buf) ;
+			goto research;
+		    }
+		}
+		// Note, that we copy name to user space via temporary
+		// buffer (local_buf) because filldir will block if
+		// user space buffer is swapped out. At that time
+		// entry can move to somewhere else
+		memcpy (local_buf, d_name, d_reclen);
+		if (filldir (dirent, d_name, d_reclen, d_off, d_ino, 
+		             DT_UNKNOWN) < 0) {
+		    if (local_buf != small_buf) {
+			kfree(local_buf) ;
+		    }
+		    goto end;
+		}
+		if (local_buf != small_buf) {
+		    kfree(local_buf) ;
+		}
+
+		// next entry should be looked for with such offset
+		next_pos = deh_offset (deh) + 1;
+
+		if (item_moved (&tmp_ih, &path_to_entry)) {
+		    reiserfs_warning ("vs-9020: reiserfs_readdir "
+				      "things are moving under hands. Researching..\n");
+		    goto research;
+		}
+	    } /* for */
+	}
+
+	if (item_num != B_NR_ITEMS (bh) - 1)
+	    // end of directory has been reached
+	    goto end;
+
+	/* item we went through is last item of node. Using right
+	   delimiting key check is it directory end */
+	rkey = get_rkey (&path_to_entry, inode->i_sb);
+	if (! comp_le_keys (rkey, &MIN_KEY)) {
+#ifdef CONFIG_REISERFS_CHECK
+	    reiserfs_warning ("vs-9025: reiserfs_readdir:"
+			      "get_rkey failed. Researching..\n");
+#endif
+	    /* set pos_key to key, that is the smallest and greater
+	       that key of the last entry in the item */
+	    set_cpu_key_k_offset (&pos_key, next_pos);
+	    continue;
+	}
+
+	if ( COMP_SHORT_KEYS (rkey, &pos_key)) {
+	    // end of directory has been reached
+	    goto end;
+	}
+	
+	/* directory continues in the right neighboring block */
+	set_cpu_key_k_offset (&pos_key, le_key_k_offset (ITEM_VERSION_1, rkey));
+
+    } /* while */
+
+
+ end:
+    // FIXME: ext2_readdir does not reset f_pos
+    filp->f_pos = next_pos;
+    pathrelse (&path_to_entry);
+    reiserfs_check_path(&path_to_entry) ;
+    return 0;
+}
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+