cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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xfs_itable.c (12366B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
      4 * All Rights Reserved.
      5 */
      6#include "xfs.h"
      7#include "xfs_fs.h"
      8#include "xfs_shared.h"
      9#include "xfs_format.h"
     10#include "xfs_log_format.h"
     11#include "xfs_trans_resv.h"
     12#include "xfs_mount.h"
     13#include "xfs_inode.h"
     14#include "xfs_btree.h"
     15#include "xfs_ialloc.h"
     16#include "xfs_ialloc_btree.h"
     17#include "xfs_iwalk.h"
     18#include "xfs_itable.h"
     19#include "xfs_error.h"
     20#include "xfs_icache.h"
     21#include "xfs_health.h"
     22#include "xfs_trans.h"
     23
     24/*
     25 * Bulk Stat
     26 * =========
     27 *
     28 * Use the inode walking functions to fill out struct xfs_bulkstat for every
     29 * allocated inode, then pass the stat information to some externally provided
     30 * iteration function.
     31 */
     32
     33struct xfs_bstat_chunk {
     34	bulkstat_one_fmt_pf	formatter;
     35	struct xfs_ibulk	*breq;
     36	struct xfs_bulkstat	*buf;
     37};
     38
     39/*
     40 * Fill out the bulkstat info for a single inode and report it somewhere.
     41 *
     42 * bc->breq->lastino is effectively the inode cursor as we walk through the
     43 * filesystem.  Therefore, we update it any time we need to move the cursor
     44 * forward, regardless of whether or not we're sending any bstat information
     45 * back to userspace.  If the inode is internal metadata or, has been freed
     46 * out from under us, we just simply keep going.
     47 *
     48 * However, if any other type of error happens we want to stop right where we
     49 * are so that userspace will call back with exact number of the bad inode and
     50 * we can send back an error code.
     51 *
     52 * Note that if the formatter tells us there's no space left in the buffer we
     53 * move the cursor forward and abort the walk.
     54 */
     55STATIC int
     56xfs_bulkstat_one_int(
     57	struct xfs_mount	*mp,
     58	struct user_namespace	*mnt_userns,
     59	struct xfs_trans	*tp,
     60	xfs_ino_t		ino,
     61	struct xfs_bstat_chunk	*bc)
     62{
     63	struct user_namespace	*sb_userns = mp->m_super->s_user_ns;
     64	struct xfs_inode	*ip;		/* incore inode pointer */
     65	struct inode		*inode;
     66	struct xfs_bulkstat	*buf = bc->buf;
     67	xfs_extnum_t		nextents;
     68	int			error = -EINVAL;
     69
     70	if (xfs_internal_inum(mp, ino))
     71		goto out_advance;
     72
     73	error = xfs_iget(mp, tp, ino,
     74			 (XFS_IGET_DONTCACHE | XFS_IGET_UNTRUSTED),
     75			 XFS_ILOCK_SHARED, &ip);
     76	if (error == -ENOENT || error == -EINVAL)
     77		goto out_advance;
     78	if (error)
     79		goto out;
     80
     81	ASSERT(ip != NULL);
     82	ASSERT(ip->i_imap.im_blkno != 0);
     83	inode = VFS_I(ip);
     84
     85	/* xfs_iget returns the following without needing
     86	 * further change.
     87	 */
     88	buf->bs_projectid = ip->i_projid;
     89	buf->bs_ino = ino;
     90	buf->bs_uid = from_kuid(sb_userns, i_uid_into_mnt(mnt_userns, inode));
     91	buf->bs_gid = from_kgid(sb_userns, i_gid_into_mnt(mnt_userns, inode));
     92	buf->bs_size = ip->i_disk_size;
     93
     94	buf->bs_nlink = inode->i_nlink;
     95	buf->bs_atime = inode->i_atime.tv_sec;
     96	buf->bs_atime_nsec = inode->i_atime.tv_nsec;
     97	buf->bs_mtime = inode->i_mtime.tv_sec;
     98	buf->bs_mtime_nsec = inode->i_mtime.tv_nsec;
     99	buf->bs_ctime = inode->i_ctime.tv_sec;
    100	buf->bs_ctime_nsec = inode->i_ctime.tv_nsec;
    101	buf->bs_gen = inode->i_generation;
    102	buf->bs_mode = inode->i_mode;
    103
    104	buf->bs_xflags = xfs_ip2xflags(ip);
    105	buf->bs_extsize_blks = ip->i_extsize;
    106
    107	nextents = xfs_ifork_nextents(&ip->i_df);
    108	if (!(bc->breq->flags & XFS_IBULK_NREXT64))
    109		buf->bs_extents = min(nextents, XFS_MAX_EXTCNT_DATA_FORK_SMALL);
    110	else
    111		buf->bs_extents64 = nextents;
    112
    113	xfs_bulkstat_health(ip, buf);
    114	buf->bs_aextents = xfs_ifork_nextents(ip->i_afp);
    115	buf->bs_forkoff = XFS_IFORK_BOFF(ip);
    116	buf->bs_version = XFS_BULKSTAT_VERSION_V5;
    117
    118	if (xfs_has_v3inodes(mp)) {
    119		buf->bs_btime = ip->i_crtime.tv_sec;
    120		buf->bs_btime_nsec = ip->i_crtime.tv_nsec;
    121		if (ip->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE)
    122			buf->bs_cowextsize_blks = ip->i_cowextsize;
    123	}
    124
    125	switch (ip->i_df.if_format) {
    126	case XFS_DINODE_FMT_DEV:
    127		buf->bs_rdev = sysv_encode_dev(inode->i_rdev);
    128		buf->bs_blksize = BLKDEV_IOSIZE;
    129		buf->bs_blocks = 0;
    130		break;
    131	case XFS_DINODE_FMT_LOCAL:
    132		buf->bs_rdev = 0;
    133		buf->bs_blksize = mp->m_sb.sb_blocksize;
    134		buf->bs_blocks = 0;
    135		break;
    136	case XFS_DINODE_FMT_EXTENTS:
    137	case XFS_DINODE_FMT_BTREE:
    138		buf->bs_rdev = 0;
    139		buf->bs_blksize = mp->m_sb.sb_blocksize;
    140		buf->bs_blocks = ip->i_nblocks + ip->i_delayed_blks;
    141		break;
    142	}
    143	xfs_iunlock(ip, XFS_ILOCK_SHARED);
    144	xfs_irele(ip);
    145
    146	error = bc->formatter(bc->breq, buf);
    147	if (error == -ECANCELED)
    148		goto out_advance;
    149	if (error)
    150		goto out;
    151
    152out_advance:
    153	/*
    154	 * Advance the cursor to the inode that comes after the one we just
    155	 * looked at.  We want the caller to move along if the bulkstat
    156	 * information was copied successfully; if we tried to grab the inode
    157	 * but it's no longer allocated; or if it's internal metadata.
    158	 */
    159	bc->breq->startino = ino + 1;
    160out:
    161	return error;
    162}
    163
    164/* Bulkstat a single inode. */
    165int
    166xfs_bulkstat_one(
    167	struct xfs_ibulk	*breq,
    168	bulkstat_one_fmt_pf	formatter)
    169{
    170	struct xfs_bstat_chunk	bc = {
    171		.formatter	= formatter,
    172		.breq		= breq,
    173	};
    174	struct xfs_trans	*tp;
    175	int			error;
    176
    177	if (breq->mnt_userns != &init_user_ns) {
    178		xfs_warn_ratelimited(breq->mp,
    179			"bulkstat not supported inside of idmapped mounts.");
    180		return -EINVAL;
    181	}
    182
    183	ASSERT(breq->icount == 1);
    184
    185	bc.buf = kmem_zalloc(sizeof(struct xfs_bulkstat),
    186			KM_MAYFAIL);
    187	if (!bc.buf)
    188		return -ENOMEM;
    189
    190	/*
    191	 * Grab an empty transaction so that we can use its recursive buffer
    192	 * locking abilities to detect cycles in the inobt without deadlocking.
    193	 */
    194	error = xfs_trans_alloc_empty(breq->mp, &tp);
    195	if (error)
    196		goto out;
    197
    198	error = xfs_bulkstat_one_int(breq->mp, breq->mnt_userns, tp,
    199			breq->startino, &bc);
    200	xfs_trans_cancel(tp);
    201out:
    202	kmem_free(bc.buf);
    203
    204	/*
    205	 * If we reported one inode to userspace then we abort because we hit
    206	 * the end of the buffer.  Don't leak that back to userspace.
    207	 */
    208	if (error == -ECANCELED)
    209		error = 0;
    210
    211	return error;
    212}
    213
    214static int
    215xfs_bulkstat_iwalk(
    216	struct xfs_mount	*mp,
    217	struct xfs_trans	*tp,
    218	xfs_ino_t		ino,
    219	void			*data)
    220{
    221	struct xfs_bstat_chunk	*bc = data;
    222	int			error;
    223
    224	error = xfs_bulkstat_one_int(mp, bc->breq->mnt_userns, tp, ino, data);
    225	/* bulkstat just skips over missing inodes */
    226	if (error == -ENOENT || error == -EINVAL)
    227		return 0;
    228	return error;
    229}
    230
    231/*
    232 * Check the incoming lastino parameter.
    233 *
    234 * We allow any inode value that could map to physical space inside the
    235 * filesystem because if there are no inodes there, bulkstat moves on to the
    236 * next chunk.  In other words, the magic agino value of zero takes us to the
    237 * first chunk in the AG, and an agino value past the end of the AG takes us to
    238 * the first chunk in the next AG.
    239 *
    240 * Therefore we can end early if the requested inode is beyond the end of the
    241 * filesystem or doesn't map properly.
    242 */
    243static inline bool
    244xfs_bulkstat_already_done(
    245	struct xfs_mount	*mp,
    246	xfs_ino_t		startino)
    247{
    248	xfs_agnumber_t		agno = XFS_INO_TO_AGNO(mp, startino);
    249	xfs_agino_t		agino = XFS_INO_TO_AGINO(mp, startino);
    250
    251	return agno >= mp->m_sb.sb_agcount ||
    252	       startino != XFS_AGINO_TO_INO(mp, agno, agino);
    253}
    254
    255/* Return stat information in bulk (by-inode) for the filesystem. */
    256int
    257xfs_bulkstat(
    258	struct xfs_ibulk	*breq,
    259	bulkstat_one_fmt_pf	formatter)
    260{
    261	struct xfs_bstat_chunk	bc = {
    262		.formatter	= formatter,
    263		.breq		= breq,
    264	};
    265	struct xfs_trans	*tp;
    266	unsigned int		iwalk_flags = 0;
    267	int			error;
    268
    269	if (breq->mnt_userns != &init_user_ns) {
    270		xfs_warn_ratelimited(breq->mp,
    271			"bulkstat not supported inside of idmapped mounts.");
    272		return -EINVAL;
    273	}
    274	if (xfs_bulkstat_already_done(breq->mp, breq->startino))
    275		return 0;
    276
    277	bc.buf = kmem_zalloc(sizeof(struct xfs_bulkstat),
    278			KM_MAYFAIL);
    279	if (!bc.buf)
    280		return -ENOMEM;
    281
    282	/*
    283	 * Grab an empty transaction so that we can use its recursive buffer
    284	 * locking abilities to detect cycles in the inobt without deadlocking.
    285	 */
    286	error = xfs_trans_alloc_empty(breq->mp, &tp);
    287	if (error)
    288		goto out;
    289
    290	if (breq->flags & XFS_IBULK_SAME_AG)
    291		iwalk_flags |= XFS_IWALK_SAME_AG;
    292
    293	error = xfs_iwalk(breq->mp, tp, breq->startino, iwalk_flags,
    294			xfs_bulkstat_iwalk, breq->icount, &bc);
    295	xfs_trans_cancel(tp);
    296out:
    297	kmem_free(bc.buf);
    298
    299	/*
    300	 * We found some inodes, so clear the error status and return them.
    301	 * The lastino pointer will point directly at the inode that triggered
    302	 * any error that occurred, so on the next call the error will be
    303	 * triggered again and propagated to userspace as there will be no
    304	 * formatted inodes in the buffer.
    305	 */
    306	if (breq->ocount > 0)
    307		error = 0;
    308
    309	return error;
    310}
    311
    312/* Convert bulkstat (v5) to bstat (v1). */
    313void
    314xfs_bulkstat_to_bstat(
    315	struct xfs_mount		*mp,
    316	struct xfs_bstat		*bs1,
    317	const struct xfs_bulkstat	*bstat)
    318{
    319	/* memset is needed here because of padding holes in the structure. */
    320	memset(bs1, 0, sizeof(struct xfs_bstat));
    321	bs1->bs_ino = bstat->bs_ino;
    322	bs1->bs_mode = bstat->bs_mode;
    323	bs1->bs_nlink = bstat->bs_nlink;
    324	bs1->bs_uid = bstat->bs_uid;
    325	bs1->bs_gid = bstat->bs_gid;
    326	bs1->bs_rdev = bstat->bs_rdev;
    327	bs1->bs_blksize = bstat->bs_blksize;
    328	bs1->bs_size = bstat->bs_size;
    329	bs1->bs_atime.tv_sec = bstat->bs_atime;
    330	bs1->bs_mtime.tv_sec = bstat->bs_mtime;
    331	bs1->bs_ctime.tv_sec = bstat->bs_ctime;
    332	bs1->bs_atime.tv_nsec = bstat->bs_atime_nsec;
    333	bs1->bs_mtime.tv_nsec = bstat->bs_mtime_nsec;
    334	bs1->bs_ctime.tv_nsec = bstat->bs_ctime_nsec;
    335	bs1->bs_blocks = bstat->bs_blocks;
    336	bs1->bs_xflags = bstat->bs_xflags;
    337	bs1->bs_extsize = XFS_FSB_TO_B(mp, bstat->bs_extsize_blks);
    338	bs1->bs_extents = bstat->bs_extents;
    339	bs1->bs_gen = bstat->bs_gen;
    340	bs1->bs_projid_lo = bstat->bs_projectid & 0xFFFF;
    341	bs1->bs_forkoff = bstat->bs_forkoff;
    342	bs1->bs_projid_hi = bstat->bs_projectid >> 16;
    343	bs1->bs_sick = bstat->bs_sick;
    344	bs1->bs_checked = bstat->bs_checked;
    345	bs1->bs_cowextsize = XFS_FSB_TO_B(mp, bstat->bs_cowextsize_blks);
    346	bs1->bs_dmevmask = 0;
    347	bs1->bs_dmstate = 0;
    348	bs1->bs_aextents = bstat->bs_aextents;
    349}
    350
    351struct xfs_inumbers_chunk {
    352	inumbers_fmt_pf		formatter;
    353	struct xfs_ibulk	*breq;
    354};
    355
    356/*
    357 * INUMBERS
    358 * ========
    359 * This is how we export inode btree records to userspace, so that XFS tools
    360 * can figure out where inodes are allocated.
    361 */
    362
    363/*
    364 * Format the inode group structure and report it somewhere.
    365 *
    366 * Similar to xfs_bulkstat_one_int, lastino is the inode cursor as we walk
    367 * through the filesystem so we move it forward unless there was a runtime
    368 * error.  If the formatter tells us the buffer is now full we also move the
    369 * cursor forward and abort the walk.
    370 */
    371STATIC int
    372xfs_inumbers_walk(
    373	struct xfs_mount	*mp,
    374	struct xfs_trans	*tp,
    375	xfs_agnumber_t		agno,
    376	const struct xfs_inobt_rec_incore *irec,
    377	void			*data)
    378{
    379	struct xfs_inumbers	inogrp = {
    380		.xi_startino	= XFS_AGINO_TO_INO(mp, agno, irec->ir_startino),
    381		.xi_alloccount	= irec->ir_count - irec->ir_freecount,
    382		.xi_allocmask	= ~irec->ir_free,
    383		.xi_version	= XFS_INUMBERS_VERSION_V5,
    384	};
    385	struct xfs_inumbers_chunk *ic = data;
    386	int			error;
    387
    388	error = ic->formatter(ic->breq, &inogrp);
    389	if (error && error != -ECANCELED)
    390		return error;
    391
    392	ic->breq->startino = XFS_AGINO_TO_INO(mp, agno, irec->ir_startino) +
    393			XFS_INODES_PER_CHUNK;
    394	return error;
    395}
    396
    397/*
    398 * Return inode number table for the filesystem.
    399 */
    400int
    401xfs_inumbers(
    402	struct xfs_ibulk	*breq,
    403	inumbers_fmt_pf		formatter)
    404{
    405	struct xfs_inumbers_chunk ic = {
    406		.formatter	= formatter,
    407		.breq		= breq,
    408	};
    409	struct xfs_trans	*tp;
    410	int			error = 0;
    411
    412	if (xfs_bulkstat_already_done(breq->mp, breq->startino))
    413		return 0;
    414
    415	/*
    416	 * Grab an empty transaction so that we can use its recursive buffer
    417	 * locking abilities to detect cycles in the inobt without deadlocking.
    418	 */
    419	error = xfs_trans_alloc_empty(breq->mp, &tp);
    420	if (error)
    421		goto out;
    422
    423	error = xfs_inobt_walk(breq->mp, tp, breq->startino, breq->flags,
    424			xfs_inumbers_walk, breq->icount, &ic);
    425	xfs_trans_cancel(tp);
    426out:
    427
    428	/*
    429	 * We found some inode groups, so clear the error status and return
    430	 * them.  The lastino pointer will point directly at the inode that
    431	 * triggered any error that occurred, so on the next call the error
    432	 * will be triggered again and propagated to userspace as there will be
    433	 * no formatted inode groups in the buffer.
    434	 */
    435	if (breq->ocount > 0)
    436		error = 0;
    437
    438	return error;
    439}
    440
    441/* Convert an inumbers (v5) struct to a inogrp (v1) struct. */
    442void
    443xfs_inumbers_to_inogrp(
    444	struct xfs_inogrp		*ig1,
    445	const struct xfs_inumbers	*ig)
    446{
    447	/* memset is needed here because of padding holes in the structure. */
    448	memset(ig1, 0, sizeof(struct xfs_inogrp));
    449	ig1->xi_startino = ig->xi_startino;
    450	ig1->xi_alloccount = ig->xi_alloccount;
    451	ig1->xi_allocmask = ig->xi_allocmask;
    452}