xfs_itable.c

linux 内核源代码

				irbp->ir_startino = gino;
				irbp->ir_freecount = gcnt;
				irbp->ir_free = gfree;
				irbp++;
				agino = gino + XFS_INODES_PER_CHUNK;
				icount = XFS_INODES_PER_CHUNK - gcnt;
			} else {
				/*
				 * If any of those tests failed, bump the
				 * inode number (just in case).
				 */
				agino++;
				icount = 0;
			}
			/*
			 * In any case, increment to the next record.
			 */
			if (!error)
				error = xfs_inobt_increment(cur, 0, &tmp);
		} else {
			/*
			 * Start of ag.  Lookup the first inode chunk.
			 */
			error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &tmp);
			icount = 0;
		}
		/*
		 * Loop through inode btree records in this ag,
		 * until we run out of inodes or space in the buffer.
		 */
		while (irbp < irbufend && icount < ubcount) {
			/*
			 * Loop as long as we're unable to read the
			 * inode btree.
			 */
			while (error) {
				agino += XFS_INODES_PER_CHUNK;
				if (XFS_AGINO_TO_AGBNO(mp, agino) >=
						be32_to_cpu(agi->agi_length))
					break;
				error = xfs_inobt_lookup_ge(cur, agino, 0, 0,
							    &tmp);
				cond_resched();
			}
			/*
			 * If ran off the end of the ag either with an error,
			 * or the normal way, set end and stop collecting.
			 */
			if (error ||
			    (error = xfs_inobt_get_rec(cur, &gino, &gcnt,
				    &gfree, &i)) ||
			    i == 0) {
				end_of_ag = 1;
				break;
			}
			/*
			 * If this chunk has any allocated inodes, save it.
			 * Also start read-ahead now for this chunk.
			 */
			if (gcnt < XFS_INODES_PER_CHUNK) {
				/*
				 * Loop over all clusters in the next chunk.
				 * Do a readahead if there are any allocated
				 * inodes in that cluster.
				 */
				for (agbno = XFS_AGINO_TO_AGBNO(mp, gino),
				     chunkidx = 0;
				     chunkidx < XFS_INODES_PER_CHUNK;
				     chunkidx += nicluster,
				     agbno += nbcluster) {
					if (XFS_INOBT_MASKN(chunkidx,
							    nicluster) & ~gfree)
						xfs_btree_reada_bufs(mp, agno,
							agbno, nbcluster);
				}
				irbp->ir_startino = gino;
				irbp->ir_freecount = gcnt;
				irbp->ir_free = gfree;
				irbp++;
				icount += XFS_INODES_PER_CHUNK - gcnt;
			}
			/*
			 * Set agino to after this chunk and bump the cursor.
			 */
			agino = gino + XFS_INODES_PER_CHUNK;
			error = xfs_inobt_increment(cur, 0, &tmp);
			cond_resched();
		}
		/*
		 * Drop the btree buffers and the agi buffer.
		 * We can't hold any of the locks these represent
		 * when calling iget.
		 */
		xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
		xfs_buf_relse(agbp);
		/*
		 * Now format all the good inodes into the user's buffer.
		 */
		irbufend = irbp;
		for (irbp = irbuf;
		     irbp < irbufend && XFS_BULKSTAT_UBLEFT(ubleft); irbp++) {
			/*
			 * Now process this chunk of inodes.
			 */
			for (agino = irbp->ir_startino, chunkidx = clustidx = 0;
			     XFS_BULKSTAT_UBLEFT(ubleft) &&
				irbp->ir_freecount < XFS_INODES_PER_CHUNK;
			     chunkidx++, clustidx++, agino++) {
				ASSERT(chunkidx < XFS_INODES_PER_CHUNK);
				/*
				 * Recompute agbno if this is the
				 * first inode of the cluster.
				 *
				 * Careful with clustidx.   There can be
				 * multple clusters per chunk, a single
				 * cluster per chunk or a cluster that has
				 * inodes represented from several different
				 * chunks (if blocksize is large).
				 *
				 * Because of this, the starting clustidx is
				 * initialized to zero in this loop but must
				 * later be reset after reading in the cluster
				 * buffer.
				 */
				if ((chunkidx & (nicluster - 1)) == 0) {
					agbno = XFS_AGINO_TO_AGBNO(mp,
							irbp->ir_startino) +
						((chunkidx & nimask) >>
						 mp->m_sb.sb_inopblog);

					if (flags & (BULKSTAT_FG_QUICK |
						     BULKSTAT_FG_INLINE)) {
						ino = XFS_AGINO_TO_INO(mp, agno,
								       agino);
						bno = XFS_AGB_TO_DADDR(mp, agno,
								       agbno);

						/*
						 * Get the inode cluster buffer
						 */
						ASSERT(xfs_inode_zone != NULL);
						ip = kmem_zone_zalloc(xfs_inode_zone,
								      KM_SLEEP);
						ip->i_ino = ino;
						ip->i_mount = mp;
						spin_lock_init(&ip->i_flags_lock);
						if (bp)
							xfs_buf_relse(bp);
						error = xfs_itobp(mp, NULL, ip,
								&dip, &bp, bno,
								XFS_IMAP_BULKSTAT);
						if (!error)
							clustidx = ip->i_boffset / mp->m_sb.sb_inodesize;
						kmem_zone_free(xfs_inode_zone, ip);
						if (XFS_TEST_ERROR(error != 0,
								   mp, XFS_ERRTAG_BULKSTAT_READ_CHUNK,
								   XFS_RANDOM_BULKSTAT_READ_CHUNK)) {
							bp = NULL;
							ubleft = 0;
							rval = error;
							break;
						}
					}
				}
				ino = XFS_AGINO_TO_INO(mp, agno, agino);
				bno = XFS_AGB_TO_DADDR(mp, agno, agbno);
				/*
				 * Skip if this inode is free.
				 */
				if (XFS_INOBT_MASK(chunkidx) & irbp->ir_free) {
					lastino = ino;
					continue;
				}
				/*
				 * Count used inodes as free so we can tell
				 * when the chunk is used up.
				 */
				irbp->ir_freecount++;
				if (!xfs_bulkstat_use_dinode(mp, flags, bp,
							     clustidx, &dip)) {
					lastino = ino;
					continue;
				}
				/*
				 * If we need to do an iget, cannot hold bp.
				 * Drop it, until starting the next cluster.
				 */
				if ((flags & BULKSTAT_FG_INLINE) && !dip) {
					if (bp)
						xfs_buf_relse(bp);
					bp = NULL;
				}

				/*
				 * Get the inode and fill in a single buffer.
				 * BULKSTAT_FG_QUICK uses dip to fill it in.
				 * BULKSTAT_FG_IGET uses igets.
				 * BULKSTAT_FG_INLINE uses dip if we have an
				 * inline attr fork, else igets.
				 * See: xfs_bulkstat_one & xfs_dm_bulkstat_one.
				 * This is also used to count inodes/blks, etc
				 * in xfs_qm_quotacheck.
				 */
				ubused = statstruct_size;
				error = formatter(mp, ino, ubufp,
						ubleft, private_data,
						bno, &ubused, dip, &fmterror);
				if (fmterror == BULKSTAT_RV_NOTHING) {
					if (error && error != ENOENT &&
						error != EINVAL) {
						ubleft = 0;
						rval = error;
						break;
					}
					lastino = ino;
					continue;
				}
				if (fmterror == BULKSTAT_RV_GIVEUP) {
					ubleft = 0;
					ASSERT(error);
					rval = error;
					break;
				}
				if (ubufp)
					ubufp += ubused;
				ubleft -= ubused;
				ubelem++;
				lastino = ino;
			}

			cond_resched();
		}

		if (bp)
			xfs_buf_relse(bp);

		/*
		 * Set up for the next loop iteration.
		 */
		if (XFS_BULKSTAT_UBLEFT(ubleft)) {
			if (end_of_ag) {
				agno++;
				agino = 0;
			} else
				agino = XFS_INO_TO_AGINO(mp, lastino);
		} else
			break;
	}
	/*
	 * Done, we're either out of filesystem or space to put the data.
	 */
	kmem_free(irbuf, irbsize);
	*ubcountp = ubelem;
	/*
	 * Found some inodes, return them now and return the error next time.
	 */
	if (ubelem)
		rval = 0;
	if (agno >= mp->m_sb.sb_agcount) {
		/*
		 * If we ran out of filesystem, mark lastino as off
		 * the end of the filesystem, so the next call
		 * will return immediately.
		 */
		*lastinop = (xfs_ino_t)XFS_AGINO_TO_INO(mp, agno, 0);
		*done = 1;
	} else
		*lastinop = (xfs_ino_t)lastino;

	return rval;
}

/*
 * Return stat information in bulk (by-inode) for the filesystem.
 * Special case for non-sequential one inode bulkstat.
 */
int					/* error status */
xfs_bulkstat_single(
	xfs_mount_t		*mp,	/* mount point for filesystem */
	xfs_ino_t		*lastinop, /* inode to return */
	char			__user *buffer, /* buffer with inode stats */
	int			*done)	/* 1 if there are more stats to get */
{
	int			count;	/* count value for bulkstat call */
	int			error;	/* return value */
	xfs_ino_t		ino;	/* filesystem inode number */
	int			res;	/* result from bs1 */

	/*
	 * note that requesting valid inode numbers which are not allocated
	 * to inodes will most likely cause xfs_itobp to generate warning
	 * messages about bad magic numbers. This is ok. The fact that
	 * the inode isn't actually an inode is handled by the
	 * error check below. Done this way to make the usual case faster
	 * at the expense of the error case.
	 */

	ino = (xfs_ino_t)*lastinop;
	error = xfs_bulkstat_one(mp, ino, buffer, sizeof(xfs_bstat_t),
				 NULL, 0, NULL, NULL, &res);
	if (error) {
		/*
		 * Special case way failed, do it the "long" way
		 * to see if that works.
		 */
		(*lastinop)--;
		count = 1;
		if (xfs_bulkstat(mp, lastinop, &count, xfs_bulkstat_one,
				NULL, sizeof(xfs_bstat_t), buffer,
				BULKSTAT_FG_IGET, done))
			return error;
		if (count == 0 || (xfs_ino_t)*lastinop != ino)
			return error == EFSCORRUPTED ?
				XFS_ERROR(EINVAL) : error;
		else
			return 0;
	}
	*done = 0;
	return 0;
}

int
xfs_inumbers_fmt(
	void			__user *ubuffer, /* buffer to write to */
	const xfs_inogrp_t	*buffer,	/* buffer to read from */
	long			count,		/* # of elements to read */
	long			*written)	/* # of bytes written */
{
	if (copy_to_user(ubuffer, buffer, count * sizeof(*buffer)))
		return -EFAULT;
	*written = count * sizeof(*buffer);
	return 0;
}

/*
 * Return inode number table for the filesystem.
 */
int					/* error status */
xfs_inumbers(
	xfs_mount_t	*mp,		/* mount point for filesystem */
	xfs_ino_t	*lastino,	/* last inode returned */
	int		*count,		/* size of buffer/count returned */
	void		__user *ubuffer,/* buffer with inode descriptions */
	inumbers_fmt_pf	formatter)
{
	xfs_buf_t	*agbp;
	xfs_agino_t	agino;
	xfs_agnumber_t	agno;
	int		bcount;
	xfs_inogrp_t	*buffer;
	int		bufidx;
	xfs_btree_cur_t	*cur;
	int		error;
	__int32_t	gcnt;
	xfs_inofree_t	gfree;
	xfs_agino_t	gino;
	int		i;
	xfs_ino_t	ino;
	int		left;
	int		tmp;

	ino = (xfs_ino_t)*lastino;
	agno = XFS_INO_TO_AGNO(mp, ino);
	agino = XFS_INO_TO_AGINO(mp, ino);
	left = *count;
	*count = 0;
	bcount = MIN(left, (int)(NBPP / sizeof(*buffer)));
	buffer = kmem_alloc(bcount * sizeof(*buffer), KM_SLEEP);
	error = bufidx = 0;
	cur = NULL;
	agbp = NULL;
	while (left > 0 && agno < mp->m_sb.sb_agcount) {
		if (agbp == NULL) {
			down_read(&mp->m_peraglock);
			error = xfs_ialloc_read_agi(mp, NULL, agno, &agbp);
			up_read(&mp->m_peraglock);
			if (error) {
				/*
				 * If we can't read the AGI of this ag,
				 * then just skip to the next one.
				 */
				ASSERT(cur == NULL);
				agbp = NULL;
				agno++;
				agino = 0;
				continue;
			}
			cur = xfs_btree_init_cursor(mp, NULL, agbp, agno,
				XFS_BTNUM_INO, (xfs_inode_t *)0, 0);
			error = xfs_inobt_lookup_ge(cur, agino, 0, 0, &tmp);
			if (error) {
				xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
				cur = NULL;
				xfs_buf_relse(agbp);
				agbp = NULL;
				/*
				 * Move up the last inode in the current
				 * chunk.  The lookup_ge will always get
				 * us the first inode in the next chunk.
				 */
				agino += XFS_INODES_PER_CHUNK - 1;
				continue;
			}
		}
		if ((error = xfs_inobt_get_rec(cur, &gino, &gcnt, &gfree,
			&i)) ||
		    i == 0) {
			xfs_buf_relse(agbp);
			agbp = NULL;
			xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
			cur = NULL;
			agno++;
			agino = 0;
			continue;
		}
		agino = gino + XFS_INODES_PER_CHUNK - 1;
		buffer[bufidx].xi_startino = XFS_AGINO_TO_INO(mp, agno, gino);
		buffer[bufidx].xi_alloccount = XFS_INODES_PER_CHUNK - gcnt;
		buffer[bufidx].xi_allocmask = ~gfree;
		bufidx++;
		left--;
		if (bufidx == bcount) {
			long written;
			if (formatter(ubuffer, buffer, bufidx, &written)) {
				error = XFS_ERROR(EFAULT);
				break;
			}
			ubuffer += written;
			*count += bufidx;
			bufidx = 0;
		}
		if (left) {
			error = xfs_inobt_increment(cur, 0, &tmp);
			if (error) {
				xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
				cur = NULL;
				xfs_buf_relse(agbp);
				agbp = NULL;
				/*
				 * The agino value has already been bumped.
				 * Just try to skip up to it.
				 */
				agino += XFS_INODES_PER_CHUNK;
				continue;
			}
		}
	}
	if (!error) {
		if (bufidx) {
			long written;
			if (formatter(ubuffer, buffer, bufidx, &written))
				error = XFS_ERROR(EFAULT);
			else
				*count += bufidx;
		}
		*lastino = XFS_AGINO_TO_INO(mp, agno, agino);
	}
	kmem_free(buffer, bcount * sizeof(*buffer));
	if (cur)
		xfs_btree_del_cursor(cur, (error ? XFS_BTREE_ERROR :
					   XFS_BTREE_NOERROR));
	if (agbp)
		xfs_buf_relse(agbp);
	return error;
}