libxfs/inode.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */

#include "libxfs_priv.h"
#include "libxfs.h"
#include "libxfs_io.h"
#include "init.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_defer.h"
#include "xfs_inode_buf.h"
#include "xfs_inode_fork.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_bmap.h"
#include "xfs_bmap_btree.h"
#include "xfs_trans_space.h"
#include "xfs_ialloc.h"
#include "xfs_alloc.h"
#include "xfs_bit.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_dir2_priv.h"

/*
 * Initialise a newly allocated inode and return the in-core inode to the
 * caller locked exclusively.
 */
int
libxfs_icreate(
	struct xfs_trans	*tp,
	xfs_ino_t		ino,
	const struct xfs_icreate_args *args,
	struct xfs_inode	**ipp)
{
	struct xfs_mount	*mp = tp->t_mountp;
	struct xfs_inode	*ip = NULL;
	int			error;

	error = libxfs_iget(mp, tp, ino, XFS_IGET_CREATE, &ip);
	if (error)
		return error;

	ASSERT(ip != NULL);
	xfs_trans_ijoin(tp, ip, 0);
	xfs_inode_init(tp, args, ip);

	*ipp = ip;
	return 0;
}

/* Set up inode attributes for newly created internal files. */
void
libxfs_icreate_args_rootfile(
	struct xfs_icreate_args	*args,
	struct xfs_mount	*mp,
	umode_t			mode,
	bool			init_xattrs)
{
	args->idmap = NULL;
	args->uid = make_kuid(0);
	args->gid = make_kgid(0);
	args->prid = 0;
	args->mode = mode;
	args->flags = XFS_ICREATE_ARGS_FORCE_UID |
		      XFS_ICREATE_ARGS_FORCE_GID |
		      XFS_ICREATE_ARGS_FORCE_MODE;
	if (init_xattrs)
		args->flags |= XFS_ICREATE_ARGS_INIT_XATTRS;
}

/*
 * Writes a modified inode's changes out to the inode's on disk home.
 * Originally based on xfs_iflush_int() from xfs_inode.c in the kernel.
 */
int
libxfs_iflush_int(
	struct xfs_inode		*ip,
	struct xfs_buf			*bp)
{
	struct xfs_inode_log_item	*iip;
	struct xfs_dinode		*dip;
	struct xfs_mount		*mp;

	ASSERT(ip->i_df.if_format != XFS_DINODE_FMT_BTREE ||
		ip->i_df.if_nextents > ip->i_df.if_ext_max);

	iip = ip->i_itemp;
	mp = ip->i_mount;

	/* set *dip = inode's place in the buffer */
	dip = xfs_buf_offset(bp, ip->i_imap.im_boffset);

	if (XFS_ISREG(ip)) {
		ASSERT( (ip->i_df.if_format == XFS_DINODE_FMT_EXTENTS) ||
			(ip->i_df.if_format == XFS_DINODE_FMT_BTREE) );
	} else if (XFS_ISDIR(ip)) {
		ASSERT( (ip->i_df.if_format == XFS_DINODE_FMT_EXTENTS) ||
			(ip->i_df.if_format == XFS_DINODE_FMT_BTREE)   ||
			(ip->i_df.if_format == XFS_DINODE_FMT_LOCAL) );
	}
	ASSERT(ip->i_df.if_nextents+ip.i_af->if_nextents <= ip->i_nblocks);
	ASSERT(ip->i_forkoff <= mp->m_sb.sb_inodesize);

	/* bump the change count on v3 inodes */
	if (xfs_has_v3inodes(mp))
		VFS_I(ip)->i_version++;

	/*
	 * If there are inline format data / attr forks attached to this inode,
	 * make sure they are not corrupt.
	 */
	if (ip->i_df.if_format == XFS_DINODE_FMT_LOCAL &&
	    xfs_ifork_verify_local_data(ip))
		return -EFSCORRUPTED;
	if (xfs_inode_has_attr_fork(ip) &&
	    ip->i_af.if_format == XFS_DINODE_FMT_LOCAL &&
	    xfs_ifork_verify_local_attr(ip))
		return -EFSCORRUPTED;

	/*
	 * Copy the dirty parts of the inode into the on-disk
	 * inode.  We always copy out the core of the inode,
	 * because if the inode is dirty at all the core must
	 * be.
	 */
	xfs_inode_to_disk(ip, dip, iip->ili_item.li_lsn);

	xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK);
	if (xfs_inode_has_attr_fork(ip))
		xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK);

	/* generate the checksum. */
	xfs_dinode_calc_crc(mp, dip);

	return 0;
}

/*
 * Inode cache stubs.
 */

struct kmem_cache		*xfs_inode_cache;
extern struct kmem_cache	*xfs_ili_cache;

int
libxfs_iget(
	struct xfs_mount	*mp,
	struct xfs_trans	*tp,
	xfs_ino_t		ino,
	uint			flags,
	struct xfs_inode	**ipp)
{
	struct xfs_inode	*ip;
	struct xfs_perag	*pag;
	int			error = 0;

	/* reject inode numbers outside existing AGs */
	if (!ino || XFS_INO_TO_AGNO(mp, ino) >= mp->m_sb.sb_agcount)
		return -EINVAL;

	ip = kmem_cache_zalloc(xfs_inode_cache, 0);
	if (!ip)
		return -ENOMEM;

	VFS_I(ip)->i_count = 1;
	ip->i_ino = ino;
	ip->i_mount = mp;
	ip->i_diflags2 = mp->m_ino_geo.new_diflags2;
	ip->i_af.if_format = XFS_DINODE_FMT_EXTENTS;
	ip->i_next_unlinked = NULLAGINO;
	ip->i_prev_unlinked = NULLAGINO;
	spin_lock_init(&VFS_I(ip)->i_lock);

	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
	error = xfs_imap(pag, tp, ip->i_ino, &ip->i_imap, 0);
	xfs_perag_put(pag);

	if (error)
		goto out_destroy;

	/*
	 * For version 5 superblocks, if we are initialising a new inode and we
	 * are not utilising the XFS_MOUNT_IKEEP inode cluster mode, we can
	 * simply build the new inode core with a random generation number.
	 *
	 * For version 4 (and older) superblocks, log recovery is dependent on
	 * the di_flushiter field being initialised from the current on-disk
	 * value and hence we must also read the inode off disk even when
	 * initializing new inodes.
	 */
	if (xfs_has_v3inodes(mp) &&
	    (flags & XFS_IGET_CREATE) && !xfs_has_ikeep(mp)) {
		VFS_I(ip)->i_generation = get_random_u32();
	} else {
		struct xfs_buf		*bp;

		error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &bp);
		if (error)
			goto out_destroy;

		error = xfs_inode_from_disk(ip,
				xfs_buf_offset(bp, ip->i_imap.im_boffset));
		if (!error)
			xfs_buf_set_ref(bp, XFS_INO_REF);
		xfs_trans_brelse(tp, bp);

		if (error)
			goto out_destroy;
	}

	*ipp = ip;
	return 0;

out_destroy:
	kmem_cache_free(xfs_inode_cache, ip);
	*ipp = NULL;
	return error;
}

/*
 * Get a metadata inode.  The ftype must match exactly.  Caller must supply
 * a transaction (even if empty) to avoid livelocking if the inobt has a cycle.
 */
int
libxfs_imeta_iget(
	struct xfs_trans	*tp,
	xfs_ino_t		ino,
	unsigned char		ftype,
	struct xfs_inode	**ipp)
{
	struct xfs_mount	*mp = tp->t_mountp;
	struct xfs_inode	*ip;
	int			error;

	error = libxfs_iget(mp, tp, ino, XFS_IGET_UNTRUSTED, &ip);
	if (error)
		return error;

	if ((xfs_has_metadir(mp) && !xfs_is_metadir_inode(ip)) ||
	    ftype == XFS_DIR3_FT_UNKNOWN ||
	    xfs_mode_to_ftype(VFS_I(ip)->i_mode) != ftype) {
		libxfs_irele(ip);
		return -EFSCORRUPTED;
	}

	*ipp = ip;
	return 0;
}

static void
libxfs_idestroy(
	struct xfs_inode	*ip)
{
	switch (VFS_I(ip)->i_mode & S_IFMT) {
		case S_IFREG:
		case S_IFDIR:
		case S_IFLNK:
			libxfs_idestroy_fork(&ip->i_df);
			break;
	}

	libxfs_ifork_zap_attr(ip);

	if (ip->i_cowfp) {
		libxfs_idestroy_fork(ip->i_cowfp);
		kmem_cache_free(xfs_ifork_cache, ip->i_cowfp);
	}
}

void
libxfs_irele(
	struct xfs_inode	*ip)
{
	VFS_I(ip)->i_count--;

	if (VFS_I(ip)->i_count == 0) {
		ASSERT(ip->i_itemp == NULL);
		libxfs_idestroy(ip);
		kmem_cache_free(xfs_inode_cache, ip);
	}
}

void
libxfs_imeta_irele(
	struct xfs_inode	*ip)
{
	ASSERT(!xfs_has_metadir(ip->i_mount) || xfs_is_metadir_inode(ip));

	libxfs_irele(ip);
}

static inline void inode_fsgid_set(struct inode *inode,
				   struct mnt_idmap *idmap)
{
	inode->i_gid = make_kgid(0);
}

void inode_init_owner(struct mnt_idmap *idmap, struct inode *inode,
		      const struct inode *dir, umode_t mode)
{
	inode_fsuid_set(inode, idmap);
	if (dir && dir->i_mode & S_ISGID) {
		inode->i_gid = dir->i_gid;

		/* Directories are special, and always inherit S_ISGID */
		if (S_ISDIR(mode))
			mode |= S_ISGID;
	} else
		inode_fsgid_set(inode, idmap);
	inode->i_mode = mode;
}

/*
 * This call is used to indicate that the buffer is going to
 * be staled and was an inode buffer. This means it gets
 * special processing during unpin - where any inodes
 * associated with the buffer should be removed from ail.
 * There is also special processing during recovery,
 * any replay of the inodes in the buffer needs to be
 * prevented as the buffer may have been reused.
 */
static void
xfs_trans_stale_inode_buf(
	xfs_trans_t		*tp,
	struct xfs_buf		*bp)
{
	ASSERT(bp->b_transp == tp);
	ASSERT(bip != NULL);
	ASSERT(atomic_read(&bip->bli_refcount) > 0);

	bp->b_flags |= _XBF_INODES;
	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DINO_BUF);
}

/*
 * A big issue when freeing the inode cluster is that we _cannot_ skip any
 * inodes that are in memory - they all must be marked stale and attached to
 * the cluster buffer.
 */
int
libxfs_ifree_cluster(
	struct xfs_trans	*tp,
	struct xfs_perag	*pag,
	struct xfs_inode	*free_ip,
	struct xfs_icluster	*xic)
{
	struct xfs_mount	*mp = free_ip->i_mount;
	struct xfs_ino_geometry	*igeo = M_IGEO(mp);
	struct xfs_buf		*bp;
	xfs_daddr_t		blkno;
	xfs_ino_t		inum = xic->first_ino;
	int			nbufs;
	int			j;
	int			ioffset;
	int			error;

	nbufs = igeo->ialloc_blks / igeo->blocks_per_cluster;

	for (j = 0; j < nbufs; j++, inum += igeo->inodes_per_cluster) {
		/*
		 * The allocation bitmap tells us which inodes of the chunk were
		 * physically allocated. Skip the cluster if an inode falls into
		 * a sparse region.
		 */
		ioffset = inum - xic->first_ino;
		if ((xic->alloc & XFS_INOBT_MASK(ioffset)) == 0) {
			ASSERT(ioffset % igeo->inodes_per_cluster == 0);
			continue;
		}

		blkno = XFS_AGB_TO_DADDR(mp, XFS_INO_TO_AGNO(mp, inum),
					 XFS_INO_TO_AGBNO(mp, inum));

		/*
		 * We obtain and lock the backing buffer first in the process
		 * here to ensure dirty inodes attached to the buffer remain in
		 * the flushing state while we mark them stale.
		 *
		 * If we scan the in-memory inodes first, then buffer IO can
		 * complete before we get a lock on it, and hence we may fail
		 * to mark all the active inodes on the buffer stale.
		 */
		error = xfs_trans_get_buf(tp, mp->m_ddev_targp, blkno,
				mp->m_bsize * igeo->blocks_per_cluster,
				XBF_UNMAPPED, &bp);
		if (error)
			return error;

		/*
		 * This buffer may not have been correctly initialised as we
		 * didn't read it from disk. That's not important because we are
		 * only using to mark the buffer as stale in the log, and to
		 * attach stale cached inodes on it. That means it will never be
		 * dispatched for IO. If it is, we want to know about it, and we
		 * want it to fail. We can acheive this by adding a write
		 * verifier to the buffer.
		 */
		bp->b_ops = &xfs_inode_buf_ops;

		xfs_trans_stale_inode_buf(tp, bp);
		xfs_trans_binval(tp, bp);
	}
	return 0;
}