xfs_attr_leaf.c

linux 内核源代码

xfs_attr_shortform_getvalue(xfs_da_args_t *args)
{
	xfs_attr_shortform_t *sf;
	xfs_attr_sf_entry_t *sfe;
	int i;

	ASSERT(args->dp->i_d.di_aformat == XFS_IFINLINE);
	sf = (xfs_attr_shortform_t *)args->dp->i_afp->if_u1.if_data;
	sfe = &sf->list[0];
	for (i = 0; i < sf->hdr.count;
				sfe = XFS_ATTR_SF_NEXTENTRY(sfe), i++) {
		if (sfe->namelen != args->namelen)
			continue;
		if (memcmp(args->name, sfe->nameval, args->namelen) != 0)
			continue;
		if (!xfs_attr_namesp_match(args->flags, sfe->flags))
			continue;
		if (args->flags & ATTR_KERNOVAL) {
			args->valuelen = sfe->valuelen;
			return(XFS_ERROR(EEXIST));
		}
		if (args->valuelen < sfe->valuelen) {
			args->valuelen = sfe->valuelen;
			return(XFS_ERROR(ERANGE));
		}
		args->valuelen = sfe->valuelen;
		memcpy(args->value, &sfe->nameval[args->namelen],
						    args->valuelen);
		return(XFS_ERROR(EEXIST));
	}
	return(XFS_ERROR(ENOATTR));
}

/*
 * Convert from using the shortform to the leaf.
 */
int
xfs_attr_shortform_to_leaf(xfs_da_args_t *args)
{
	xfs_inode_t *dp;
	xfs_attr_shortform_t *sf;
	xfs_attr_sf_entry_t *sfe;
	xfs_da_args_t nargs;
	char *tmpbuffer;
	int error, i, size;
	xfs_dablk_t blkno;
	xfs_dabuf_t *bp;
	xfs_ifork_t *ifp;

	dp = args->dp;
	ifp = dp->i_afp;
	sf = (xfs_attr_shortform_t *)ifp->if_u1.if_data;
	size = be16_to_cpu(sf->hdr.totsize);
	tmpbuffer = kmem_alloc(size, KM_SLEEP);
	ASSERT(tmpbuffer != NULL);
	memcpy(tmpbuffer, ifp->if_u1.if_data, size);
	sf = (xfs_attr_shortform_t *)tmpbuffer;

	xfs_idata_realloc(dp, -size, XFS_ATTR_FORK);
	bp = NULL;
	error = xfs_da_grow_inode(args, &blkno);
	if (error) {
		/*
		 * If we hit an IO error middle of the transaction inside
		 * grow_inode(), we may have inconsistent data. Bail out.
		 */
		if (error == EIO)
			goto out;
		xfs_idata_realloc(dp, size, XFS_ATTR_FORK);	/* try to put */
		memcpy(ifp->if_u1.if_data, tmpbuffer, size);	/* it back */
		goto out;
	}

	ASSERT(blkno == 0);
	error = xfs_attr_leaf_create(args, blkno, &bp);
	if (error) {
		error = xfs_da_shrink_inode(args, 0, bp);
		bp = NULL;
		if (error)
			goto out;
		xfs_idata_realloc(dp, size, XFS_ATTR_FORK);	/* try to put */
		memcpy(ifp->if_u1.if_data, tmpbuffer, size);	/* it back */
		goto out;
	}

	memset((char *)&nargs, 0, sizeof(nargs));
	nargs.dp = dp;
	nargs.firstblock = args->firstblock;
	nargs.flist = args->flist;
	nargs.total = args->total;
	nargs.whichfork = XFS_ATTR_FORK;
	nargs.trans = args->trans;
	nargs.oknoent = 1;

	sfe = &sf->list[0];
	for (i = 0; i < sf->hdr.count; i++) {
		nargs.name = (char *)sfe->nameval;
		nargs.namelen = sfe->namelen;
		nargs.value = (char *)&sfe->nameval[nargs.namelen];
		nargs.valuelen = sfe->valuelen;
		nargs.hashval = xfs_da_hashname((char *)sfe->nameval,
						sfe->namelen);
		nargs.flags = XFS_ATTR_NSP_ONDISK_TO_ARGS(sfe->flags);
		error = xfs_attr_leaf_lookup_int(bp, &nargs); /* set a->index */
		ASSERT(error == ENOATTR);
		error = xfs_attr_leaf_add(bp, &nargs);
		ASSERT(error != ENOSPC);
		if (error)
			goto out;
		sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
	}
	error = 0;

out:
	if(bp)
		xfs_da_buf_done(bp);
	kmem_free(tmpbuffer, size);
	return(error);
}

STATIC int
xfs_attr_shortform_compare(const void *a, const void *b)
{
	xfs_attr_sf_sort_t *sa, *sb;

	sa = (xfs_attr_sf_sort_t *)a;
	sb = (xfs_attr_sf_sort_t *)b;
	if (sa->hash < sb->hash) {
		return(-1);
	} else if (sa->hash > sb->hash) {
		return(1);
	} else {
		return(sa->entno - sb->entno);
	}
}


#define XFS_ISRESET_CURSOR(cursor) \
	(!((cursor)->initted) && !((cursor)->hashval) && \
	 !((cursor)->blkno) && !((cursor)->offset))
/*
 * Copy out entries of shortform attribute lists for attr_list().
 * Shortform attribute lists are not stored in hashval sorted order.
 * If the output buffer is not large enough to hold them all, then we
 * we have to calculate each entries' hashvalue and sort them before
 * we can begin returning them to the user.
 */
/*ARGSUSED*/
int
xfs_attr_shortform_list(xfs_attr_list_context_t *context)
{
	attrlist_cursor_kern_t *cursor;
	xfs_attr_sf_sort_t *sbuf, *sbp;
	xfs_attr_shortform_t *sf;
	xfs_attr_sf_entry_t *sfe;
	xfs_inode_t *dp;
	int sbsize, nsbuf, count, i;
	int error;

	ASSERT(context != NULL);
	dp = context->dp;
	ASSERT(dp != NULL);
	ASSERT(dp->i_afp != NULL);
	sf = (xfs_attr_shortform_t *)dp->i_afp->if_u1.if_data;
	ASSERT(sf != NULL);
	if (!sf->hdr.count)
		return(0);
	cursor = context->cursor;
	ASSERT(cursor != NULL);

	xfs_attr_trace_l_c("sf start", context);

	/*
	 * If the buffer is large enough and the cursor is at the start,
	 * do not bother with sorting since we will return everything in
	 * one buffer and another call using the cursor won't need to be
	 * made.
	 * Note the generous fudge factor of 16 overhead bytes per entry.
	 * If bufsize is zero then put_listent must be a search function
	 * and can just scan through what we have.
	 */
	if (context->bufsize == 0 ||
	    (XFS_ISRESET_CURSOR(cursor) &&
             (dp->i_afp->if_bytes + sf->hdr.count * 16) < context->bufsize)) {
		for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
			attrnames_t	*namesp;

			if (!xfs_attr_namesp_match_overrides(context->flags, sfe->flags)) {
				sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
				continue;
			}
			namesp = xfs_attr_flags_namesp(sfe->flags);
			error = context->put_listent(context,
					   namesp,
					   (char *)sfe->nameval,
					   (int)sfe->namelen,
					   (int)sfe->valuelen,
					   (char*)&sfe->nameval[sfe->namelen]);

			/*
			 * Either search callback finished early or
			 * didn't fit it all in the buffer after all.
			 */
			if (context->seen_enough)
				break;

			if (error)
				return error;
			sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
		}
		xfs_attr_trace_l_c("sf big-gulp", context);
		return(0);
	}

	/* do no more for a search callback */
	if (context->bufsize == 0)
		return 0;

	/*
	 * It didn't all fit, so we have to sort everything on hashval.
	 */
	sbsize = sf->hdr.count * sizeof(*sbuf);
	sbp = sbuf = kmem_alloc(sbsize, KM_SLEEP);

	/*
	 * Scan the attribute list for the rest of the entries, storing
	 * the relevant info from only those that match into a buffer.
	 */
	nsbuf = 0;
	for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
		if (unlikely(
		    ((char *)sfe < (char *)sf) ||
		    ((char *)sfe >= ((char *)sf + dp->i_afp->if_bytes)))) {
			XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
					     XFS_ERRLEVEL_LOW,
					     context->dp->i_mount, sfe);
			xfs_attr_trace_l_c("sf corrupted", context);
			kmem_free(sbuf, sbsize);
			return XFS_ERROR(EFSCORRUPTED);
		}
		if (!xfs_attr_namesp_match_overrides(context->flags, sfe->flags)) {
			sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
			continue;
		}
		sbp->entno = i;
		sbp->hash = xfs_da_hashname((char *)sfe->nameval, sfe->namelen);
		sbp->name = (char *)sfe->nameval;
		sbp->namelen = sfe->namelen;
		/* These are bytes, and both on-disk, don't endian-flip */
		sbp->valuelen = sfe->valuelen;
		sbp->flags = sfe->flags;
		sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
		sbp++;
		nsbuf++;
	}

	/*
	 * Sort the entries on hash then entno.
	 */
	xfs_sort(sbuf, nsbuf, sizeof(*sbuf), xfs_attr_shortform_compare);

	/*
	 * Re-find our place IN THE SORTED LIST.
	 */
	count = 0;
	cursor->initted = 1;
	cursor->blkno = 0;
	for (sbp = sbuf, i = 0; i < nsbuf; i++, sbp++) {
		if (sbp->hash == cursor->hashval) {
			if (cursor->offset == count) {
				break;
			}
			count++;
		} else if (sbp->hash > cursor->hashval) {
			break;
		}
	}
	if (i == nsbuf) {
		kmem_free(sbuf, sbsize);
		xfs_attr_trace_l_c("blk end", context);
		return(0);
	}

	/*
	 * Loop putting entries into the user buffer.
	 */
	for ( ; i < nsbuf; i++, sbp++) {
		attrnames_t	*namesp;

		namesp = xfs_attr_flags_namesp(sbp->flags);

		if (cursor->hashval != sbp->hash) {
			cursor->hashval = sbp->hash;
			cursor->offset = 0;
		}
		error = context->put_listent(context,
					namesp,
					sbp->name,
					sbp->namelen,
					sbp->valuelen,
					&sbp->name[sbp->namelen]);
		if (error)
			return error;
		if (context->seen_enough)
			break;
		cursor->offset++;
	}

	kmem_free(sbuf, sbsize);
	xfs_attr_trace_l_c("sf E-O-F", context);
	return(0);
}

/*
 * Check a leaf attribute block to see if all the entries would fit into
 * a shortform attribute list.
 */
int
xfs_attr_shortform_allfit(xfs_dabuf_t *bp, xfs_inode_t *dp)
{
	xfs_attr_leafblock_t *leaf;
	xfs_attr_leaf_entry_t *entry;
	xfs_attr_leaf_name_local_t *name_loc;
	int bytes, i;

	leaf = bp->data;
	ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);

	entry = &leaf->entries[0];
	bytes = sizeof(struct xfs_attr_sf_hdr);
	for (i = 0; i < be16_to_cpu(leaf->hdr.count); entry++, i++) {
		if (entry->flags & XFS_ATTR_INCOMPLETE)
			continue;		/* don't copy partial entries */
		if (!(entry->flags & XFS_ATTR_LOCAL))
			return(0);
		name_loc = XFS_ATTR_LEAF_NAME_LOCAL(leaf, i);
		if (name_loc->namelen >= XFS_ATTR_SF_ENTSIZE_MAX)
			return(0);
		if (be16_to_cpu(name_loc->valuelen) >= XFS_ATTR_SF_ENTSIZE_MAX)
			return(0);
		bytes += sizeof(struct xfs_attr_sf_entry)-1
				+ name_loc->namelen
				+ be16_to_cpu(name_loc->valuelen);
	}
	if ((dp->i_mount->m_flags & XFS_MOUNT_ATTR2) &&
	    (dp->i_d.di_format != XFS_DINODE_FMT_BTREE) &&
	    (bytes == sizeof(struct xfs_attr_sf_hdr)))
		return(-1);
	return(xfs_attr_shortform_bytesfit(dp, bytes));
}

/*
 * Convert a leaf attribute list to shortform attribute list
 */
int
xfs_attr_leaf_to_shortform(xfs_dabuf_t *bp, xfs_da_args_t *args, int forkoff)
{
	xfs_attr_leafblock_t *leaf;
	xfs_attr_leaf_entry_t *entry;
	xfs_attr_leaf_name_local_t *name_loc;
	xfs_da_args_t nargs;
	xfs_inode_t *dp;
	char *tmpbuffer;
	int error, i;

	dp = args->dp;
	tmpbuffer = kmem_alloc(XFS_LBSIZE(dp->i_mount), KM_SLEEP);
	ASSERT(tmpbuffer != NULL);

	ASSERT(bp != NULL);
	memcpy(tmpbuffer, bp->data, XFS_LBSIZE(dp->i_mount));
	leaf = (xfs_attr_leafblock_t *)tmpbuffer;
	ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
	memset(bp->data, 0, XFS_LBSIZE(dp->i_mount));

	/*
	 * Clean out the prior contents of the attribute list.
	 */
	error = xfs_da_shrink_inode(args, 0, bp);
	if (error)
		goto out;

	if (forkoff == -1) {
		ASSERT(dp->i_mount->m_flags & XFS_MOUNT_ATTR2);
		ASSERT(dp->i_d.di_format != XFS_DINODE_FMT_BTREE);

		/*
		 * Last attribute was removed, revert to original
		 * inode format making all literal area available
		 * to the data fork once more.
		 */
		xfs_idestroy_fork(dp, XFS_ATTR_FORK);
		dp->i_d.di_forkoff = 0;
		dp->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
		ASSERT(dp->i_d.di_anextents == 0);
		ASSERT(dp->i_afp == NULL);
		dp->i_df.if_ext_max =
			XFS_IFORK_DSIZE(dp) / (uint)sizeof(xfs_bmbt_rec_t);
		xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
		goto out;
	}

	xfs_attr_shortform_create(args);

	/*
	 * Copy the attributes
	 */
	memset((char *)&nargs, 0, sizeof(nargs));
	nargs.dp = dp;
	nargs.firstblock = args->firstblock;
	nargs.flist = args->flist;
	nargs.total = args->total;
	nargs.whichfork = XFS_ATTR_FORK;
	nargs.trans = args->trans;
	nargs.oknoent = 1;
	entry = &leaf->entries[0];
	for (i = 0; i < be16_to_cpu(leaf->hdr.count); entry++, i++) {
		if (entry->flags & XFS_ATTR_INCOMPLETE)
			continue;	/* don't copy partial entries */
		if (!entry->nameidx)
			continue;
		ASSERT(entry->flags & XFS_ATTR_LOCAL);
		name_loc = XFS_ATTR_LEAF_NAME_LOCAL(leaf, i);
		nargs.name = (char *)name_loc->nameval;
		nargs.namelen = name_loc->namelen;
		nargs.value = (char *)&name_loc->nameval[nargs.namelen];
		nargs.valuelen = be16_to_cpu(name_loc->valuelen);
		nargs.hashval = be32_to_cpu(entry->hashval);
		nargs.flags = XFS_ATTR_NSP_ONDISK_TO_ARGS(entry->flags);
		xfs_attr_shortform_add(&nargs, forkoff);
	}
	error = 0;

out:
	kmem_free(tmpbuffer, XFS_LBSIZE(dp->i_mount));
	return(error);
}

/*
 * Convert from using a single leaf to a root node and a leaf.
 */
int
xfs_attr_leaf_to_node(xfs_da_args_t *args)