xfs_dir2_sf.c

linux 内核源代码

	/*
	 * Special case for ..
	 */
	if (args->namelen == 2 &&
	    args->name[0] == '.' && args->name[1] == '.') {
		args->inumber = xfs_dir2_sf_get_inumber(sfp, &sfp->hdr.parent);
		return XFS_ERROR(EEXIST);
	}
	/*
	 * Loop over all the entries trying to match ours.
	 */
	for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp);
	     i < sfp->hdr.count;
	     i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep)) {
		if (sfep->namelen == args->namelen &&
		    sfep->name[0] == args->name[0] &&
		    memcmp(args->name, sfep->name, args->namelen) == 0) {
			args->inumber =
				xfs_dir2_sf_get_inumber(sfp,
					xfs_dir2_sf_inumberp(sfep));
			return XFS_ERROR(EEXIST);
		}
	}
	/*
	 * Didn't find it.
	 */
	ASSERT(args->oknoent);
	return XFS_ERROR(ENOENT);
}

/*
 * Remove an entry from a shortform directory.
 */
int						/* error */
xfs_dir2_sf_removename(
	xfs_da_args_t		*args)
{
	int			byteoff;	/* offset of removed entry */
	xfs_inode_t		*dp;		/* incore directory inode */
	int			entsize;	/* this entry's size */
	int			i;		/* shortform entry index */
	int			newsize;	/* new inode size */
	int			oldsize;	/* old inode size */
	xfs_dir2_sf_entry_t	*sfep;		/* shortform directory entry */
	xfs_dir2_sf_t		*sfp;		/* shortform structure */

	xfs_dir2_trace_args("sf_removename", args);
	dp = args->dp;

	ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
	oldsize = (int)dp->i_d.di_size;
	/*
	 * Bail out if the directory is way too short.
	 */
	if (oldsize < offsetof(xfs_dir2_sf_hdr_t, parent)) {
		ASSERT(XFS_FORCED_SHUTDOWN(dp->i_mount));
		return XFS_ERROR(EIO);
	}
	ASSERT(dp->i_df.if_bytes == oldsize);
	ASSERT(dp->i_df.if_u1.if_data != NULL);
	sfp = (xfs_dir2_sf_t *)dp->i_df.if_u1.if_data;
	ASSERT(oldsize >= xfs_dir2_sf_hdr_size(sfp->hdr.i8count));
	/*
	 * Loop over the old directory entries.
	 * Find the one we're deleting.
	 */
	for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp);
	     i < sfp->hdr.count;
	     i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep)) {
		if (sfep->namelen == args->namelen &&
		    sfep->name[0] == args->name[0] &&
		    memcmp(sfep->name, args->name, args->namelen) == 0) {
			ASSERT(xfs_dir2_sf_get_inumber(sfp,
					xfs_dir2_sf_inumberp(sfep)) ==
				args->inumber);
			break;
		}
	}
	/*
	 * Didn't find it.
	 */
	if (i == sfp->hdr.count) {
		return XFS_ERROR(ENOENT);
	}
	/*
	 * Calculate sizes.
	 */
	byteoff = (int)((char *)sfep - (char *)sfp);
	entsize = xfs_dir2_sf_entsize_byname(sfp, args->namelen);
	newsize = oldsize - entsize;
	/*
	 * Copy the part if any after the removed entry, sliding it down.
	 */
	if (byteoff + entsize < oldsize)
		memmove((char *)sfp + byteoff, (char *)sfp + byteoff + entsize,
			oldsize - (byteoff + entsize));
	/*
	 * Fix up the header and file size.
	 */
	sfp->hdr.count--;
	dp->i_d.di_size = newsize;
	/*
	 * Reallocate, making it smaller.
	 */
	xfs_idata_realloc(dp, newsize - oldsize, XFS_DATA_FORK);
	sfp = (xfs_dir2_sf_t *)dp->i_df.if_u1.if_data;
#if XFS_BIG_INUMS
	/*
	 * Are we changing inode number size?
	 */
	if (args->inumber > XFS_DIR2_MAX_SHORT_INUM) {
		if (sfp->hdr.i8count == 1)
			xfs_dir2_sf_toino4(args);
		else
			sfp->hdr.i8count--;
	}
#endif
	xfs_dir2_sf_check(args);
	xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_DDATA);
	return 0;
}

/*
 * Replace the inode number of an entry in a shortform directory.
 */
int						/* error */
xfs_dir2_sf_replace(
	xfs_da_args_t		*args)		/* operation arguments */
{
	xfs_inode_t		*dp;		/* incore directory inode */
	int			i;		/* entry index */
#if XFS_BIG_INUMS || defined(DEBUG)
	xfs_ino_t		ino=0;		/* entry old inode number */
#endif
#if XFS_BIG_INUMS
	int			i8elevated;	/* sf_toino8 set i8count=1 */
#endif
	xfs_dir2_sf_entry_t	*sfep;		/* shortform directory entry */
	xfs_dir2_sf_t		*sfp;		/* shortform structure */

	xfs_dir2_trace_args("sf_replace", args);
	dp = args->dp;

	ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
	/*
	 * Bail out if the shortform directory is way too small.
	 */
	if (dp->i_d.di_size < offsetof(xfs_dir2_sf_hdr_t, parent)) {
		ASSERT(XFS_FORCED_SHUTDOWN(dp->i_mount));
		return XFS_ERROR(EIO);
	}
	ASSERT(dp->i_df.if_bytes == dp->i_d.di_size);
	ASSERT(dp->i_df.if_u1.if_data != NULL);
	sfp = (xfs_dir2_sf_t *)dp->i_df.if_u1.if_data;
	ASSERT(dp->i_d.di_size >= xfs_dir2_sf_hdr_size(sfp->hdr.i8count));
#if XFS_BIG_INUMS
	/*
	 * New inode number is large, and need to convert to 8-byte inodes.
	 */
	if (args->inumber > XFS_DIR2_MAX_SHORT_INUM && sfp->hdr.i8count == 0) {
		int	error;			/* error return value */
		int	newsize;		/* new inode size */

		newsize =
			dp->i_df.if_bytes +
			(sfp->hdr.count + 1) *
			((uint)sizeof(xfs_dir2_ino8_t) -
			 (uint)sizeof(xfs_dir2_ino4_t));
		/*
		 * Won't fit as shortform, convert to block then do replace.
		 */
		if (newsize > XFS_IFORK_DSIZE(dp)) {
			error = xfs_dir2_sf_to_block(args);
			if (error) {
				return error;
			}
			return xfs_dir2_block_replace(args);
		}
		/*
		 * Still fits, convert to 8-byte now.
		 */
		xfs_dir2_sf_toino8(args);
		i8elevated = 1;
		sfp = (xfs_dir2_sf_t *)dp->i_df.if_u1.if_data;
	} else
		i8elevated = 0;
#endif
	ASSERT(args->namelen != 1 || args->name[0] != '.');
	/*
	 * Replace ..'s entry.
	 */
	if (args->namelen == 2 &&
	    args->name[0] == '.' && args->name[1] == '.') {
#if XFS_BIG_INUMS || defined(DEBUG)
		ino = xfs_dir2_sf_get_inumber(sfp, &sfp->hdr.parent);
		ASSERT(args->inumber != ino);
#endif
		xfs_dir2_sf_put_inumber(sfp, &args->inumber, &sfp->hdr.parent);
	}
	/*
	 * Normal entry, look for the name.
	 */
	else {
		for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp);
		     i < sfp->hdr.count;
		     i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep)) {
			if (sfep->namelen == args->namelen &&
			    sfep->name[0] == args->name[0] &&
			    memcmp(args->name, sfep->name, args->namelen) == 0) {
#if XFS_BIG_INUMS || defined(DEBUG)
				ino = xfs_dir2_sf_get_inumber(sfp,
					xfs_dir2_sf_inumberp(sfep));
				ASSERT(args->inumber != ino);
#endif
				xfs_dir2_sf_put_inumber(sfp, &args->inumber,
					xfs_dir2_sf_inumberp(sfep));
				break;
			}
		}
		/*
		 * Didn't find it.
		 */
		if (i == sfp->hdr.count) {
			ASSERT(args->oknoent);
#if XFS_BIG_INUMS
			if (i8elevated)
				xfs_dir2_sf_toino4(args);
#endif
			return XFS_ERROR(ENOENT);
		}
	}
#if XFS_BIG_INUMS
	/*
	 * See if the old number was large, the new number is small.
	 */
	if (ino > XFS_DIR2_MAX_SHORT_INUM &&
	    args->inumber <= XFS_DIR2_MAX_SHORT_INUM) {
		/*
		 * And the old count was one, so need to convert to small.
		 */
		if (sfp->hdr.i8count == 1)
			xfs_dir2_sf_toino4(args);
		else
			sfp->hdr.i8count--;
	}
	/*
	 * See if the old number was small, the new number is large.
	 */
	if (ino <= XFS_DIR2_MAX_SHORT_INUM &&
	    args->inumber > XFS_DIR2_MAX_SHORT_INUM) {
		/*
		 * add to the i8count unless we just converted to 8-byte
		 * inodes (which does an implied i8count = 1)
		 */
		ASSERT(sfp->hdr.i8count != 0);
		if (!i8elevated)
			sfp->hdr.i8count++;
	}
#endif
	xfs_dir2_sf_check(args);
	xfs_trans_log_inode(args->trans, dp, XFS_ILOG_DDATA);
	return 0;
}

#if XFS_BIG_INUMS
/*
 * Convert from 8-byte inode numbers to 4-byte inode numbers.
 * The last 8-byte inode number is gone, but the count is still 1.
 */
static void
xfs_dir2_sf_toino4(
	xfs_da_args_t		*args)		/* operation arguments */
{
	char			*buf;		/* old dir's buffer */
	xfs_inode_t		*dp;		/* incore directory inode */
	int			i;		/* entry index */
	xfs_ino_t		ino;		/* entry inode number */
	int			newsize;	/* new inode size */
	xfs_dir2_sf_entry_t	*oldsfep;	/* old sf entry */
	xfs_dir2_sf_t		*oldsfp;	/* old sf directory */
	int			oldsize;	/* old inode size */
	xfs_dir2_sf_entry_t	*sfep;		/* new sf entry */
	xfs_dir2_sf_t		*sfp;		/* new sf directory */

	xfs_dir2_trace_args("sf_toino4", args);
	dp = args->dp;

	/*
	 * Copy the old directory to the buffer.
	 * Then nuke it from the inode, and add the new buffer to the inode.
	 * Don't want xfs_idata_realloc copying the data here.
	 */
	oldsize = dp->i_df.if_bytes;
	buf = kmem_alloc(oldsize, KM_SLEEP);
	oldsfp = (xfs_dir2_sf_t *)dp->i_df.if_u1.if_data;
	ASSERT(oldsfp->hdr.i8count == 1);
	memcpy(buf, oldsfp, oldsize);
	/*
	 * Compute the new inode size.
	 */
	newsize =
		oldsize -
		(oldsfp->hdr.count + 1) *
		((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t));
	xfs_idata_realloc(dp, -oldsize, XFS_DATA_FORK);
	xfs_idata_realloc(dp, newsize, XFS_DATA_FORK);
	/*
	 * Reset our pointers, the data has moved.
	 */
	oldsfp = (xfs_dir2_sf_t *)buf;
	sfp = (xfs_dir2_sf_t *)dp->i_df.if_u1.if_data;
	/*
	 * Fill in the new header.
	 */
	sfp->hdr.count = oldsfp->hdr.count;
	sfp->hdr.i8count = 0;
	ino = xfs_dir2_sf_get_inumber(oldsfp, &oldsfp->hdr.parent);
	xfs_dir2_sf_put_inumber(sfp, &ino, &sfp->hdr.parent);
	/*
	 * Copy the entries field by field.
	 */
	for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp),
		    oldsfep = xfs_dir2_sf_firstentry(oldsfp);
	     i < sfp->hdr.count;
	     i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep),
		  oldsfep = xfs_dir2_sf_nextentry(oldsfp, oldsfep)) {
		sfep->namelen = oldsfep->namelen;
		sfep->offset = oldsfep->offset;
		memcpy(sfep->name, oldsfep->name, sfep->namelen);
		ino = xfs_dir2_sf_get_inumber(oldsfp,
			xfs_dir2_sf_inumberp(oldsfep));
		xfs_dir2_sf_put_inumber(sfp, &ino, xfs_dir2_sf_inumberp(sfep));
	}
	/*
	 * Clean up the inode.
	 */
	kmem_free(buf, oldsize);
	dp->i_d.di_size = newsize;
	xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_DDATA);
}

/*
 * Convert from 4-byte inode numbers to 8-byte inode numbers.
 * The new 8-byte inode number is not there yet, we leave with the
 * count 1 but no corresponding entry.
 */
static void
xfs_dir2_sf_toino8(
	xfs_da_args_t		*args)		/* operation arguments */
{
	char			*buf;		/* old dir's buffer */
	xfs_inode_t		*dp;		/* incore directory inode */
	int			i;		/* entry index */
	xfs_ino_t		ino;		/* entry inode number */
	int			newsize;	/* new inode size */
	xfs_dir2_sf_entry_t	*oldsfep;	/* old sf entry */
	xfs_dir2_sf_t		*oldsfp;	/* old sf directory */
	int			oldsize;	/* old inode size */
	xfs_dir2_sf_entry_t	*sfep;		/* new sf entry */
	xfs_dir2_sf_t		*sfp;		/* new sf directory */

	xfs_dir2_trace_args("sf_toino8", args);
	dp = args->dp;

	/*
	 * Copy the old directory to the buffer.
	 * Then nuke it from the inode, and add the new buffer to the inode.
	 * Don't want xfs_idata_realloc copying the data here.
	 */
	oldsize = dp->i_df.if_bytes;
	buf = kmem_alloc(oldsize, KM_SLEEP);
	oldsfp = (xfs_dir2_sf_t *)dp->i_df.if_u1.if_data;
	ASSERT(oldsfp->hdr.i8count == 0);
	memcpy(buf, oldsfp, oldsize);
	/*
	 * Compute the new inode size.
	 */
	newsize =
		oldsize +
		(oldsfp->hdr.count + 1) *
		((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t));
	xfs_idata_realloc(dp, -oldsize, XFS_DATA_FORK);
	xfs_idata_realloc(dp, newsize, XFS_DATA_FORK);
	/*
	 * Reset our pointers, the data has moved.
	 */
	oldsfp = (xfs_dir2_sf_t *)buf;
	sfp = (xfs_dir2_sf_t *)dp->i_df.if_u1.if_data;
	/*
	 * Fill in the new header.
	 */
	sfp->hdr.count = oldsfp->hdr.count;
	sfp->hdr.i8count = 1;
	ino = xfs_dir2_sf_get_inumber(oldsfp, &oldsfp->hdr.parent);
	xfs_dir2_sf_put_inumber(sfp, &ino, &sfp->hdr.parent);
	/*
	 * Copy the entries field by field.
	 */
	for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp),
		    oldsfep = xfs_dir2_sf_firstentry(oldsfp);
	     i < sfp->hdr.count;
	     i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep),
		  oldsfep = xfs_dir2_sf_nextentry(oldsfp, oldsfep)) {
		sfep->namelen = oldsfep->namelen;
		sfep->offset = oldsfep->offset;
		memcpy(sfep->name, oldsfep->name, sfep->namelen);
		ino = xfs_dir2_sf_get_inumber(oldsfp,
			xfs_dir2_sf_inumberp(oldsfep));
		xfs_dir2_sf_put_inumber(sfp, &ino, xfs_dir2_sf_inumberp(sfep));
	}
	/*
	 * Clean up the inode.
	 */
	kmem_free(buf, oldsize);
	dp->i_d.di_size = newsize;
	xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_DDATA);
}
#endif	/* XFS_BIG_INUMS */