OpenCloudOS-Kernel/fs/xfs/libxfs/xfs_inode_buf.c

723 lines
20 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2006 Silicon Graphics, Inc.
* All Rights Reserved.
*/
#include "xfs.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_inode.h"
#include "xfs_errortag.h"
#include "xfs_error.h"
#include "xfs_icache.h"
#include "xfs_trans.h"
#include "xfs_ialloc.h"
#include "xfs_dir2.h"
#include <linux/iversion.h>
/*
* Check that none of the inode's in the buffer have a next
* unlinked field of 0.
*/
#if defined(DEBUG)
void
xfs_inobp_check(
xfs_mount_t *mp,
xfs_buf_t *bp)
{
int i;
xfs_dinode_t *dip;
for (i = 0; i < M_IGEO(mp)->inodes_per_cluster; i++) {
dip = xfs_buf_offset(bp, i * mp->m_sb.sb_inodesize);
if (!dip->di_next_unlinked) {
xfs_alert(mp,
"Detected bogus zero next_unlinked field in inode %d buffer 0x%llx.",
i, (long long)bp->b_bn);
}
}
}
#endif
/*
* If we are doing readahead on an inode buffer, we might be in log recovery
* reading an inode allocation buffer that hasn't yet been replayed, and hence
* has not had the inode cores stamped into it. Hence for readahead, the buffer
* may be potentially invalid.
*
* If the readahead buffer is invalid, we need to mark it with an error and
* clear the DONE status of the buffer so that a followup read will re-read it
* from disk. We don't report the error otherwise to avoid warnings during log
* recovery and we don't get unnecssary panics on debug kernels. We use EIO here
* because all we want to do is say readahead failed; there is no-one to report
* the error to, so this will distinguish it from a non-ra verifier failure.
* Changes to this readahead error behavour also need to be reflected in
* xfs_dquot_buf_readahead_verify().
*/
static void
xfs_inode_buf_verify(
struct xfs_buf *bp,
bool readahead)
{
struct xfs_mount *mp = bp->b_mount;
xfs_agnumber_t agno;
int i;
int ni;
/*
* Validate the magic number and version of every inode in the buffer
*/
agno = xfs_daddr_to_agno(mp, XFS_BUF_ADDR(bp));
ni = XFS_BB_TO_FSB(mp, bp->b_length) * mp->m_sb.sb_inopblock;
for (i = 0; i < ni; i++) {
int di_ok;
xfs_dinode_t *dip;
xfs_agino_t unlinked_ino;
dip = xfs_buf_offset(bp, (i << mp->m_sb.sb_inodelog));
unlinked_ino = be32_to_cpu(dip->di_next_unlinked);
di_ok = xfs_verify_magic16(bp, dip->di_magic) &&
xfs_dinode_good_version(&mp->m_sb, dip->di_version) &&
xfs_verify_agino_or_null(mp, agno, unlinked_ino);
if (unlikely(XFS_TEST_ERROR(!di_ok, mp,
XFS_ERRTAG_ITOBP_INOTOBP))) {
if (readahead) {
bp->b_flags &= ~XBF_DONE;
xfs_buf_ioerror(bp, -EIO);
return;
}
#ifdef DEBUG
xfs_alert(mp,
"bad inode magic/vsn daddr %lld #%d (magic=%x)",
(unsigned long long)bp->b_bn, i,
be16_to_cpu(dip->di_magic));
#endif
xfs_buf_verifier_error(bp, -EFSCORRUPTED,
__func__, dip, sizeof(*dip),
NULL);
return;
}
}
}
static void
xfs_inode_buf_read_verify(
struct xfs_buf *bp)
{
xfs_inode_buf_verify(bp, false);
}
static void
xfs_inode_buf_readahead_verify(
struct xfs_buf *bp)
{
xfs_inode_buf_verify(bp, true);
}
static void
xfs_inode_buf_write_verify(
struct xfs_buf *bp)
{
xfs_inode_buf_verify(bp, false);
}
const struct xfs_buf_ops xfs_inode_buf_ops = {
.name = "xfs_inode",
.magic16 = { cpu_to_be16(XFS_DINODE_MAGIC),
cpu_to_be16(XFS_DINODE_MAGIC) },
.verify_read = xfs_inode_buf_read_verify,
.verify_write = xfs_inode_buf_write_verify,
};
const struct xfs_buf_ops xfs_inode_buf_ra_ops = {
.name = "xfs_inode_ra",
.magic16 = { cpu_to_be16(XFS_DINODE_MAGIC),
cpu_to_be16(XFS_DINODE_MAGIC) },
.verify_read = xfs_inode_buf_readahead_verify,
.verify_write = xfs_inode_buf_write_verify,
};
/*
* This routine is called to map an inode to the buffer containing the on-disk
* version of the inode. It returns a pointer to the buffer containing the
* on-disk inode in the bpp parameter, and in the dipp parameter it returns a
* pointer to the on-disk inode within that buffer.
*
* If a non-zero error is returned, then the contents of bpp and dipp are
* undefined.
*/
int
xfs_imap_to_bp(
struct xfs_mount *mp,
struct xfs_trans *tp,
struct xfs_imap *imap,
struct xfs_dinode **dipp,
struct xfs_buf **bpp,
uint buf_flags)
{
struct xfs_buf *bp;
int error;
buf_flags |= XBF_UNMAPPED;
error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, imap->im_blkno,
(int)imap->im_len, buf_flags, &bp,
&xfs_inode_buf_ops);
if (error) {
ASSERT(error != -EAGAIN || (buf_flags & XBF_TRYLOCK));
return error;
}
*bpp = bp;
*dipp = xfs_buf_offset(bp, imap->im_boffset);
return 0;
}
int
xfs_inode_from_disk(
struct xfs_inode *ip,
struct xfs_dinode *from)
{
struct xfs_icdinode *to = &ip->i_d;
struct inode *inode = VFS_I(ip);
int error;
xfs_failaddr_t fa;
ASSERT(ip->i_cowfp == NULL);
ASSERT(ip->i_afp == NULL);
fa = xfs_dinode_verify(ip->i_mount, ip->i_ino, from);
if (fa) {
xfs_inode_verifier_error(ip, -EFSCORRUPTED, "dinode", from,
sizeof(*from), fa);
return -EFSCORRUPTED;
}
/*
* First get the permanent information that is needed to allocate an
* inode. If the inode is unused, mode is zero and we shouldn't mess
* with the unitialized part of it.
*/
to->di_flushiter = be16_to_cpu(from->di_flushiter);
inode->i_generation = be32_to_cpu(from->di_gen);
inode->i_mode = be16_to_cpu(from->di_mode);
if (!inode->i_mode)
return 0;
/*
* Convert v1 inodes immediately to v2 inode format as this is the
* minimum inode version format we support in the rest of the code.
* They will also be unconditionally written back to disk as v2 inodes.
*/
if (unlikely(from->di_version == 1)) {
set_nlink(inode, be16_to_cpu(from->di_onlink));
to->di_projid = 0;
} else {
set_nlink(inode, be32_to_cpu(from->di_nlink));
to->di_projid = (prid_t)be16_to_cpu(from->di_projid_hi) << 16 |
be16_to_cpu(from->di_projid_lo);
}
to->di_format = from->di_format;
i_uid_write(inode, be32_to_cpu(from->di_uid));
i_gid_write(inode, be32_to_cpu(from->di_gid));
/*
* Time is signed, so need to convert to signed 32 bit before
* storing in inode timestamp which may be 64 bit. Otherwise
* a time before epoch is converted to a time long after epoch
* on 64 bit systems.
*/
inode->i_atime.tv_sec = (int)be32_to_cpu(from->di_atime.t_sec);
inode->i_atime.tv_nsec = (int)be32_to_cpu(from->di_atime.t_nsec);
inode->i_mtime.tv_sec = (int)be32_to_cpu(from->di_mtime.t_sec);
inode->i_mtime.tv_nsec = (int)be32_to_cpu(from->di_mtime.t_nsec);
inode->i_ctime.tv_sec = (int)be32_to_cpu(from->di_ctime.t_sec);
inode->i_ctime.tv_nsec = (int)be32_to_cpu(from->di_ctime.t_nsec);
to->di_size = be64_to_cpu(from->di_size);
to->di_nblocks = be64_to_cpu(from->di_nblocks);
to->di_extsize = be32_to_cpu(from->di_extsize);
to->di_nextents = be32_to_cpu(from->di_nextents);
to->di_anextents = be16_to_cpu(from->di_anextents);
to->di_forkoff = from->di_forkoff;
to->di_aformat = from->di_aformat;
to->di_dmevmask = be32_to_cpu(from->di_dmevmask);
to->di_dmstate = be16_to_cpu(from->di_dmstate);
to->di_flags = be16_to_cpu(from->di_flags);
if (xfs_sb_version_has_v3inode(&ip->i_mount->m_sb)) {
inode_set_iversion_queried(inode,
be64_to_cpu(from->di_changecount));
to->di_crtime.tv_sec = be32_to_cpu(from->di_crtime.t_sec);
to->di_crtime.tv_nsec = be32_to_cpu(from->di_crtime.t_nsec);
to->di_flags2 = be64_to_cpu(from->di_flags2);
to->di_cowextsize = be32_to_cpu(from->di_cowextsize);
}
error = xfs_iformat_data_fork(ip, from);
if (error)
return error;
if (XFS_DFORK_Q(from)) {
error = xfs_iformat_attr_fork(ip, from);
if (error)
goto out_destroy_data_fork;
}
if (xfs_is_reflink_inode(ip))
xfs_ifork_init_cow(ip);
return 0;
out_destroy_data_fork:
xfs_idestroy_fork(ip, XFS_DATA_FORK);
return error;
}
void
xfs_inode_to_disk(
struct xfs_inode *ip,
struct xfs_dinode *to,
xfs_lsn_t lsn)
{
struct xfs_icdinode *from = &ip->i_d;
struct inode *inode = VFS_I(ip);
to->di_magic = cpu_to_be16(XFS_DINODE_MAGIC);
to->di_onlink = 0;
to->di_format = from->di_format;
to->di_uid = cpu_to_be32(i_uid_read(inode));
to->di_gid = cpu_to_be32(i_gid_read(inode));
to->di_projid_lo = cpu_to_be16(from->di_projid & 0xffff);
to->di_projid_hi = cpu_to_be16(from->di_projid >> 16);
memset(to->di_pad, 0, sizeof(to->di_pad));
to->di_atime.t_sec = cpu_to_be32(inode->i_atime.tv_sec);
to->di_atime.t_nsec = cpu_to_be32(inode->i_atime.tv_nsec);
to->di_mtime.t_sec = cpu_to_be32(inode->i_mtime.tv_sec);
to->di_mtime.t_nsec = cpu_to_be32(inode->i_mtime.tv_nsec);
to->di_ctime.t_sec = cpu_to_be32(inode->i_ctime.tv_sec);
to->di_ctime.t_nsec = cpu_to_be32(inode->i_ctime.tv_nsec);
to->di_nlink = cpu_to_be32(inode->i_nlink);
to->di_gen = cpu_to_be32(inode->i_generation);
to->di_mode = cpu_to_be16(inode->i_mode);
to->di_size = cpu_to_be64(from->di_size);
to->di_nblocks = cpu_to_be64(from->di_nblocks);
to->di_extsize = cpu_to_be32(from->di_extsize);
to->di_nextents = cpu_to_be32(from->di_nextents);
to->di_anextents = cpu_to_be16(from->di_anextents);
to->di_forkoff = from->di_forkoff;
to->di_aformat = from->di_aformat;
to->di_dmevmask = cpu_to_be32(from->di_dmevmask);
to->di_dmstate = cpu_to_be16(from->di_dmstate);
to->di_flags = cpu_to_be16(from->di_flags);
if (xfs_sb_version_has_v3inode(&ip->i_mount->m_sb)) {
to->di_version = 3;
to->di_changecount = cpu_to_be64(inode_peek_iversion(inode));
to->di_crtime.t_sec = cpu_to_be32(from->di_crtime.tv_sec);
to->di_crtime.t_nsec = cpu_to_be32(from->di_crtime.tv_nsec);
to->di_flags2 = cpu_to_be64(from->di_flags2);
to->di_cowextsize = cpu_to_be32(from->di_cowextsize);
to->di_ino = cpu_to_be64(ip->i_ino);
to->di_lsn = cpu_to_be64(lsn);
memset(to->di_pad2, 0, sizeof(to->di_pad2));
uuid_copy(&to->di_uuid, &ip->i_mount->m_sb.sb_meta_uuid);
to->di_flushiter = 0;
} else {
to->di_version = 2;
to->di_flushiter = cpu_to_be16(from->di_flushiter);
}
}
void
xfs_log_dinode_to_disk(
struct xfs_log_dinode *from,
struct xfs_dinode *to)
{
to->di_magic = cpu_to_be16(from->di_magic);
to->di_mode = cpu_to_be16(from->di_mode);
to->di_version = from->di_version;
to->di_format = from->di_format;
to->di_onlink = 0;
to->di_uid = cpu_to_be32(from->di_uid);
to->di_gid = cpu_to_be32(from->di_gid);
to->di_nlink = cpu_to_be32(from->di_nlink);
to->di_projid_lo = cpu_to_be16(from->di_projid_lo);
to->di_projid_hi = cpu_to_be16(from->di_projid_hi);
memcpy(to->di_pad, from->di_pad, sizeof(to->di_pad));
to->di_atime.t_sec = cpu_to_be32(from->di_atime.t_sec);
to->di_atime.t_nsec = cpu_to_be32(from->di_atime.t_nsec);
to->di_mtime.t_sec = cpu_to_be32(from->di_mtime.t_sec);
to->di_mtime.t_nsec = cpu_to_be32(from->di_mtime.t_nsec);
to->di_ctime.t_sec = cpu_to_be32(from->di_ctime.t_sec);
to->di_ctime.t_nsec = cpu_to_be32(from->di_ctime.t_nsec);
to->di_size = cpu_to_be64(from->di_size);
to->di_nblocks = cpu_to_be64(from->di_nblocks);
to->di_extsize = cpu_to_be32(from->di_extsize);
to->di_nextents = cpu_to_be32(from->di_nextents);
to->di_anextents = cpu_to_be16(from->di_anextents);
to->di_forkoff = from->di_forkoff;
to->di_aformat = from->di_aformat;
to->di_dmevmask = cpu_to_be32(from->di_dmevmask);
to->di_dmstate = cpu_to_be16(from->di_dmstate);
to->di_flags = cpu_to_be16(from->di_flags);
to->di_gen = cpu_to_be32(from->di_gen);
if (from->di_version == 3) {
to->di_changecount = cpu_to_be64(from->di_changecount);
to->di_crtime.t_sec = cpu_to_be32(from->di_crtime.t_sec);
to->di_crtime.t_nsec = cpu_to_be32(from->di_crtime.t_nsec);
to->di_flags2 = cpu_to_be64(from->di_flags2);
to->di_cowextsize = cpu_to_be32(from->di_cowextsize);
to->di_ino = cpu_to_be64(from->di_ino);
to->di_lsn = cpu_to_be64(from->di_lsn);
memcpy(to->di_pad2, from->di_pad2, sizeof(to->di_pad2));
uuid_copy(&to->di_uuid, &from->di_uuid);
to->di_flushiter = 0;
} else {
to->di_flushiter = cpu_to_be16(from->di_flushiter);
}
}
static xfs_failaddr_t
xfs_dinode_verify_fork(
struct xfs_dinode *dip,
struct xfs_mount *mp,
int whichfork)
{
uint32_t di_nextents = XFS_DFORK_NEXTENTS(dip, whichfork);
switch (XFS_DFORK_FORMAT(dip, whichfork)) {
case XFS_DINODE_FMT_LOCAL:
/*
* no local regular files yet
*/
if (whichfork == XFS_DATA_FORK) {
if (S_ISREG(be16_to_cpu(dip->di_mode)))
return __this_address;
if (be64_to_cpu(dip->di_size) >
XFS_DFORK_SIZE(dip, mp, whichfork))
return __this_address;
}
if (di_nextents)
return __this_address;
break;
case XFS_DINODE_FMT_EXTENTS:
if (di_nextents > XFS_DFORK_MAXEXT(dip, mp, whichfork))
return __this_address;
break;
case XFS_DINODE_FMT_BTREE:
if (whichfork == XFS_ATTR_FORK) {
if (di_nextents > MAXAEXTNUM)
return __this_address;
} else if (di_nextents > MAXEXTNUM) {
return __this_address;
}
break;
default:
return __this_address;
}
return NULL;
}
static xfs_failaddr_t
xfs_dinode_verify_forkoff(
struct xfs_dinode *dip,
struct xfs_mount *mp)
{
if (!XFS_DFORK_Q(dip))
return NULL;
switch (dip->di_format) {
case XFS_DINODE_FMT_DEV:
if (dip->di_forkoff != (roundup(sizeof(xfs_dev_t), 8) >> 3))
return __this_address;
break;
case XFS_DINODE_FMT_LOCAL: /* fall through ... */
case XFS_DINODE_FMT_EXTENTS: /* fall through ... */
case XFS_DINODE_FMT_BTREE:
if (dip->di_forkoff >= (XFS_LITINO(mp) >> 3))
return __this_address;
break;
default:
return __this_address;
}
return NULL;
}
xfs_failaddr_t
xfs_dinode_verify(
struct xfs_mount *mp,
xfs_ino_t ino,
struct xfs_dinode *dip)
{
xfs_failaddr_t fa;
uint16_t mode;
uint16_t flags;
uint64_t flags2;
uint64_t di_size;
if (dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC))
return __this_address;
/* Verify v3 integrity information first */
if (dip->di_version >= 3) {
if (!xfs_sb_version_has_v3inode(&mp->m_sb))
return __this_address;
if (!xfs_verify_cksum((char *)dip, mp->m_sb.sb_inodesize,
XFS_DINODE_CRC_OFF))
return __this_address;
if (be64_to_cpu(dip->di_ino) != ino)
return __this_address;
if (!uuid_equal(&dip->di_uuid, &mp->m_sb.sb_meta_uuid))
return __this_address;
}
/* don't allow invalid i_size */
di_size = be64_to_cpu(dip->di_size);
if (di_size & (1ULL << 63))
return __this_address;
mode = be16_to_cpu(dip->di_mode);
if (mode && xfs_mode_to_ftype(mode) == XFS_DIR3_FT_UNKNOWN)
return __this_address;
/* No zero-length symlinks/dirs. */
if ((S_ISLNK(mode) || S_ISDIR(mode)) && di_size == 0)
return __this_address;
/* Fork checks carried over from xfs_iformat_fork */
if (mode &&
be32_to_cpu(dip->di_nextents) + be16_to_cpu(dip->di_anextents) >
be64_to_cpu(dip->di_nblocks))
return __this_address;
if (mode && XFS_DFORK_BOFF(dip) > mp->m_sb.sb_inodesize)
return __this_address;
flags = be16_to_cpu(dip->di_flags);
if (mode && (flags & XFS_DIFLAG_REALTIME) && !mp->m_rtdev_targp)
return __this_address;
/* check for illegal values of forkoff */
fa = xfs_dinode_verify_forkoff(dip, mp);
if (fa)
return fa;
/* Do we have appropriate data fork formats for the mode? */
switch (mode & S_IFMT) {
case S_IFIFO:
case S_IFCHR:
case S_IFBLK:
case S_IFSOCK:
if (dip->di_format != XFS_DINODE_FMT_DEV)
return __this_address;
break;
case S_IFREG:
case S_IFLNK:
case S_IFDIR:
fa = xfs_dinode_verify_fork(dip, mp, XFS_DATA_FORK);
if (fa)
return fa;
break;
case 0:
/* Uninitialized inode ok. */
break;
default:
return __this_address;
}
if (XFS_DFORK_Q(dip)) {
fa = xfs_dinode_verify_fork(dip, mp, XFS_ATTR_FORK);
if (fa)
return fa;
} else {
/*
* If there is no fork offset, this may be a freshly-made inode
* in a new disk cluster, in which case di_aformat is zeroed.
* Otherwise, such an inode must be in EXTENTS format; this goes
* for freed inodes as well.
*/
switch (dip->di_aformat) {
case 0:
case XFS_DINODE_FMT_EXTENTS:
break;
default:
return __this_address;
}
if (dip->di_anextents)
return __this_address;
}
/* extent size hint validation */
fa = xfs_inode_validate_extsize(mp, be32_to_cpu(dip->di_extsize),
mode, flags);
if (fa)
return fa;
/* only version 3 or greater inodes are extensively verified here */
if (dip->di_version < 3)
return NULL;
flags2 = be64_to_cpu(dip->di_flags2);
/* don't allow reflink/cowextsize if we don't have reflink */
if ((flags2 & (XFS_DIFLAG2_REFLINK | XFS_DIFLAG2_COWEXTSIZE)) &&
!xfs_sb_version_hasreflink(&mp->m_sb))
return __this_address;
/* only regular files get reflink */
if ((flags2 & XFS_DIFLAG2_REFLINK) && (mode & S_IFMT) != S_IFREG)
return __this_address;
/* don't let reflink and realtime mix */
if ((flags2 & XFS_DIFLAG2_REFLINK) && (flags & XFS_DIFLAG_REALTIME))
return __this_address;
/* don't let reflink and dax mix */
if ((flags2 & XFS_DIFLAG2_REFLINK) && (flags2 & XFS_DIFLAG2_DAX))
return __this_address;
/* COW extent size hint validation */
fa = xfs_inode_validate_cowextsize(mp, be32_to_cpu(dip->di_cowextsize),
mode, flags, flags2);
if (fa)
return fa;
return NULL;
}
void
xfs_dinode_calc_crc(
struct xfs_mount *mp,
struct xfs_dinode *dip)
{
uint32_t crc;
if (dip->di_version < 3)
return;
ASSERT(xfs_sb_version_hascrc(&mp->m_sb));
crc = xfs_start_cksum_update((char *)dip, mp->m_sb.sb_inodesize,
XFS_DINODE_CRC_OFF);
dip->di_crc = xfs_end_cksum(crc);
}
/*
* Validate di_extsize hint.
*
* The rules are documented at xfs_ioctl_setattr_check_extsize().
* These functions must be kept in sync with each other.
*/
xfs_failaddr_t
xfs_inode_validate_extsize(
struct xfs_mount *mp,
uint32_t extsize,
uint16_t mode,
uint16_t flags)
{
bool rt_flag;
bool hint_flag;
bool inherit_flag;
uint32_t extsize_bytes;
uint32_t blocksize_bytes;
rt_flag = (flags & XFS_DIFLAG_REALTIME);
hint_flag = (flags & XFS_DIFLAG_EXTSIZE);
inherit_flag = (flags & XFS_DIFLAG_EXTSZINHERIT);
extsize_bytes = XFS_FSB_TO_B(mp, extsize);
if (rt_flag)
blocksize_bytes = mp->m_sb.sb_rextsize << mp->m_sb.sb_blocklog;
else
blocksize_bytes = mp->m_sb.sb_blocksize;
if ((hint_flag || inherit_flag) && !(S_ISDIR(mode) || S_ISREG(mode)))
return __this_address;
if (hint_flag && !S_ISREG(mode))
return __this_address;
if (inherit_flag && !S_ISDIR(mode))
return __this_address;
if ((hint_flag || inherit_flag) && extsize == 0)
return __this_address;
/* free inodes get flags set to zero but extsize remains */
if (mode && !(hint_flag || inherit_flag) && extsize != 0)
return __this_address;
if (extsize_bytes % blocksize_bytes)
return __this_address;
if (extsize > MAXEXTLEN)
return __this_address;
if (!rt_flag && extsize > mp->m_sb.sb_agblocks / 2)
return __this_address;
return NULL;
}
/*
* Validate di_cowextsize hint.
*
* The rules are documented at xfs_ioctl_setattr_check_cowextsize().
* These functions must be kept in sync with each other.
*/
xfs_failaddr_t
xfs_inode_validate_cowextsize(
struct xfs_mount *mp,
uint32_t cowextsize,
uint16_t mode,
uint16_t flags,
uint64_t flags2)
{
bool rt_flag;
bool hint_flag;
uint32_t cowextsize_bytes;
rt_flag = (flags & XFS_DIFLAG_REALTIME);
hint_flag = (flags2 & XFS_DIFLAG2_COWEXTSIZE);
cowextsize_bytes = XFS_FSB_TO_B(mp, cowextsize);
if (hint_flag && !xfs_sb_version_hasreflink(&mp->m_sb))
return __this_address;
if (hint_flag && !(S_ISDIR(mode) || S_ISREG(mode)))
return __this_address;
if (hint_flag && cowextsize == 0)
return __this_address;
/* free inodes get flags set to zero but cowextsize remains */
if (mode && !hint_flag && cowextsize != 0)
return __this_address;
if (hint_flag && rt_flag)
return __this_address;
if (cowextsize_bytes % mp->m_sb.sb_blocksize)
return __this_address;
if (cowextsize > MAXEXTLEN)
return __this_address;
if (cowextsize > mp->m_sb.sb_agblocks / 2)
return __this_address;
return NULL;
}