- 根目录:
- fs
- xfs
- xfs_inode_buf.c
/*
* Copyright (c) 2000-2006 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#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_sb.h"
#include "xfs_ag.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_error.h"
#include "xfs_cksum.h"
#include "xfs_icache.h"
#include "xfs_trans.h"
#include "xfs_ialloc.h"
#include "xfs_dinode.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;
int j;
xfs_dinode_t *dip;
j = mp->m_inode_cluster_size >> mp->m_sb.sb_inodelog;
for (i = 0; i < j; i++) {
dip = (xfs_dinode_t *)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 don't want to mark it with an error,
* but we do want to clear the DONE status of the buffer so that a followup read
* will re-read it from disk. This will ensure that we don't get an unnecessary
* warnings during log recovery and we don't get unnecssary panics on debug
* kernels.
*/
static void
xfs_inode_buf_verify(
struct xfs_buf *bp,
bool readahead)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
int i;
int ni;
/*
* Validate the magic number and version of every inode in the buffer
*/
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;
dip = (struct xfs_dinode *)xfs_buf_offset(bp,
(i << mp->m_sb.sb_inodelog));
di_ok = dip->di_magic == cpu_to_be16(XFS_DINODE_MAGIC) &&
XFS_DINODE_GOOD_VERSION(dip->di_version);
if (unlikely(XFS_TEST_ERROR(!di_ok, mp,
XFS_ERRTAG_ITOBP_INOTOBP,
XFS_RANDOM_ITOBP_INOTOBP))) {
if (readahead) {
bp->b_flags &= ~XBF_DONE;
return;
}
xfs_buf_ioerror(bp, EFSCORRUPTED);
XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_HIGH,
mp, dip);
#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_inobp_check(mp, bp);
}
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 = {
.verify_read = xfs_inode_buf_read_verify,
.verify_write = xfs_inode_buf_write_verify,
};
const struct xfs_buf_ops xfs_inode_buf_ra_ops = {
.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,
uint iget_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) {
if (error == EAGAIN) {
ASSERT(buf_flags & XBF_TRYLOCK);
return error;
}
if (error == EFSCORRUPTED &&
(iget_flags & XFS_IGET_UNTRUSTED))
return XFS_ERROR(EINVAL);
xfs_warn(mp, "%s: xfs_trans_read_buf() returned error %d.",
__func__, error);
return error;
}
*bpp = bp;
*dipp = (struct xfs_dinode *)xfs_buf_offset(bp, imap->im_boffset);
return 0;
}
void
xfs_dinode_from_disk(
xfs_icdinode_t *to,
xfs_dinode_t *from)
{
to->di_magic = be16_to_cpu(from->di_magic);
to->di_mode = be16_to_cpu(from->di_mode);
to->di_version = from ->di_version;
to->di_format = from->di_format;
to->di_onlink = be16_to_cpu(from->di_onlink);
to->di_uid = be32_to_cpu(from->di_uid);
to->di_gid = be32_to_cpu(from->di_gid);
to->di_nlink = be32_to_cpu(from->di_nlink);
to->di_projid_lo = be16_to_cpu(from->di_projid_lo);
to->di_projid_hi = be16_to_cpu(from->di_projid_hi);
memcpy(to->di_pad, from->di_pad, sizeof(to->di_pad));
to->di_flushiter = be16_to_cpu(from->di_flushiter);
to->di_atime.t_sec = be32_to_cpu(from->di_atime.t_sec);
to->di_atime.t_nsec = be32_to_cpu(from->di_atime.t_nsec);
to->di_mtime.t_sec = be32_to_cpu(from->di_mtime.t_sec);
to->di_mtime.t_nsec = be32_to_cpu(from->di_mtime.t_nsec);
to->di_ctime.t_sec = be32_to_cpu(from->di_ctime.t_sec);
to->di_ctime.t_nsec = 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);
to->di_gen = be32_to_cpu(from->di_gen);
if (to->di_version == 3) {
to->di_changecount = be64_to_cpu(from->di_changecount);
to->di_crtime.t_sec = be32_to_cpu(from->di_crtime.t_sec);
to->di_crtime.t_nsec = be32_to_cpu(from->di_crtime.t_nsec);
to->di_flags2 = be64_to_cpu(from->di_flags2);
to->di_ino = be64_to_cpu(from->di_ino);
to->di_lsn = be64_to_cpu(from->di_lsn);
memcpy(to->di_pad2, from->di_pad2, sizeof(to->di_pad2));
uuid_copy(&to->di_uuid, &from->di_uuid);
}
}
void
xfs_dinode_to_disk(
xfs_dinode_t *to,
xfs_icdinode_t *from)
{
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 = cpu_to_be16(from->di_onlink);
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_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 bool
xfs_dinode_verify(
struct xfs_mount *mp,
struct xfs_inode *ip,
struct xfs_dinode *dip)
{
if (dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC))
return false;
/* only version 3 or greater inodes are extensively verified here */
if (dip->di_version < 3)
return true;
if (!xfs_sb_version_hascrc(&mp->m_sb))
return false;
if (!xfs_verify_cksum((char *)dip, mp->m_sb.sb_inodesize,
offsetof(struct xfs_dinode, di_crc)))
return false;
if (be64_to_cpu(dip->di_ino) != ip->i_ino)
return false;
if (!uuid_equal(&dip->di_uuid, &mp->m_sb.sb_uuid))
return false;
return true;
}
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((char *)dip, mp->m_sb.sb_inodesize,
offsetof(struct xfs_dinode, di_crc));
dip->di_crc = xfs_end_cksum(crc);
}
/*
* Read the disk inode attributes into the in-core inode structure.
*
* 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 simple build the new
* inode core with a random generation number. If we are keeping inodes around,
* we need to read the inode cluster to get the existing generation number off
* disk. Further, if we are using version 4 superblocks (i.e. v1/v2 inode
* format) then 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.
*/
int
xfs_iread(
xfs_mount_t *mp,
xfs_trans_t *tp,
xfs_inode_t *ip,
uint iget_flags)
{
xfs_buf_t *bp;
xfs_dinode_t *dip;
int error;
/*
* Fill in the location information in the in-core inode.
*/
error = xfs_imap(mp, tp, ip->i_ino, &ip->i_imap, iget_flags);
if (error)
return error;
/* shortcut IO on inode allocation if possible */
if ((iget_flags & XFS_IGET_CREATE) &&
xfs_sb_version_hascrc(&mp->m_sb) &&
!(mp->m_flags & XFS_MOUNT_IKEEP)) {
/* initialise the on-disk inode core */
memset(&ip->i_d, 0, sizeof(ip->i_d));
ip->i_d.di_magic = XFS_DINODE_MAGIC;
ip->i_d.di_gen = prandom_u32();
if (xfs_sb_version_hascrc(&mp->m_sb)) {
ip->i_d.di_version = 3;
ip->i_d.di_ino = ip->i_ino;
uuid_copy(&ip->i_d.di_uuid, &mp->m_sb.sb_uuid);
} else
ip->i_d.di_version = 2;
return 0;
}
/*
* Get pointers to the on-disk inode and the buffer containing it.
*/
error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &bp, 0, iget_flags);
if (error)
return error;
/* even unallocated inodes are verified */
if (!xfs_dinode_verify(mp, ip, dip)) {
xfs_alert(mp, "%s: validation failed for inode %lld failed",
__func__, ip->i_ino);
XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, dip);
error = XFS_ERROR(EFSCORRUPTED);
goto out_brelse;
}
/*
* If the on-disk inode is already linked to a directory
* entry, copy all of the inode into the in-core inode.
* xfs_iformat_fork() handles copying in the inode format
* specific information.
* Otherwise, just get the truly permanent information.
*/
if (dip->di_mode) {
xfs_dinode_from_disk(&ip->i_d, dip);
error = xfs_iformat_fork(ip, dip);
if (error) {
#ifdef DEBUG
xfs_alert(mp, "%s: xfs_iformat() returned error %d",
__func__, error);
#endif /* DEBUG */
goto out_brelse;
}
} else {
/*
* Partial initialisation of the in-core inode. Just the bits
* that xfs_ialloc won't overwrite or relies on being correct.
*/
ip->i_d.di_magic = be16_to_cpu(dip->di_magic);
ip->i_d.di_version = dip->di_version;
ip->i_d.di_gen = be32_to_cpu(dip->di_gen);
ip->i_d.di_flushiter = be16_to_cpu(dip->di_flushiter);
if (dip->di_version == 3) {
ip->i_d.di_ino = be64_to_cpu(dip->di_ino);
uuid_copy(&ip->i_d.di_uuid, &dip->di_uuid);
}
/*
* Make sure to pull in the mode here as well in
* case the inode is released without being used.
* This ensures that xfs_inactive() will see that
* the inode is already free and not try to mess
* with the uninitialized part of it.
*/
ip->i_d.di_mode = 0;
}
/*
* The inode format changed when we moved the link count and
* made it 32 bits long. If this is an old format inode,
* convert it in memory to look like a new one. If it gets
* flushed to disk we will convert back before flushing or
* logging it. We zero out the new projid field and the old link
* count field. We'll handle clearing the pad field (the remains
* of the old uuid field) when we actually convert the inode to
* the new format. We don't change the version number so that we
* can distinguish this from a real new format inode.
*/
if (ip->i_d.di_version == 1) {
ip->i_d.di_nlink = ip->i_d.di_onlink;
ip->i_d.di_onlink = 0;
xfs_set_projid(ip, 0);
}
ip->i_delayed_blks = 0;
/*
* Mark the buffer containing the inode as something to keep
* around for a while. This helps to keep recently accessed
* meta-data in-core longer.
*/
xfs_buf_set_ref(bp, XFS_INO_REF);
/*
* Use xfs_trans_brelse() to release the buffer containing the on-disk
* inode, because it was acquired with xfs_trans_read_buf() in
* xfs_imap_to_bp() above. If tp is NULL, this is just a normal
* brelse(). If we're within a transaction, then xfs_trans_brelse()
* will only release the buffer if it is not dirty within the
* transaction. It will be OK to release the buffer in this case,
* because inodes on disk are never destroyed and we will be locking the
* new in-core inode before putting it in the cache where other
* processes can find it. Thus we don't have to worry about the inode
* being changed just because we released the buffer.
*/
out_brelse:
xfs_trans_brelse(tp, bp);
return error;
}