/*
* Copyright (c) 2000-2004 Silicon Graphics, Inc. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2 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.
*
* Further, this software is distributed without any warranty that it is
* free of the rightful claim of any third person regarding infringement
* or the like. Any license provided herein, whether implied or
* otherwise, applies only to this software file. Patent licenses, if
* any, provided herein do not apply to combinations of this program with
* other software, or any other product whatsoever.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write the Free Software Foundation, Inc., 59
* Temple Place - Suite 330, Boston MA 02111-1307, USA.
*
* Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
* Mountain View, CA 94043, or:
*
* http://www.sgi.com
*
* For further information regarding this notice, see:
*
* http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
*/
#include <xfs/libxlog.h>
#define xlog_unpack_data_checksum(rhead, dp, log) ((void)0)
#define xlog_clear_stale_blocks(log, tail_lsn) (0)
#define xfs_readonly_buftarg(buftarg) (0)
/*
* This routine finds (to an approximation) the first block in the physical
* log which contains the given cycle. It uses a binary search algorithm.
* Note that the algorithm can not be perfect because the disk will not
* necessarily be perfect.
*/
int
xlog_find_cycle_start(
xlog_t *log,
xfs_buf_t *bp,
xfs_daddr_t first_blk,
xfs_daddr_t *last_blk,
uint cycle)
{
xfs_caddr_t offset;
xfs_daddr_t mid_blk;
uint mid_cycle;
int error;
mid_blk = BLK_AVG(first_blk, *last_blk);
while (mid_blk != first_blk && mid_blk != *last_blk) {
if ((error = xlog_bread(log, mid_blk, 1, bp)))
return error;
offset = xlog_align(log, mid_blk, 1, bp);
mid_cycle = GET_CYCLE(offset, ARCH_CONVERT);
if (mid_cycle == cycle) {
*last_blk = mid_blk;
/* last_half_cycle == mid_cycle */
} else {
first_blk = mid_blk;
/* first_half_cycle == mid_cycle */
}
mid_blk = BLK_AVG(first_blk, *last_blk);
}
ASSERT((mid_blk == first_blk && mid_blk+1 == *last_blk) ||
(mid_blk == *last_blk && mid_blk-1 == first_blk));
return 0;
}
/*
* Check that the range of blocks does not contain the cycle number
* given. The scan needs to occur from front to back and the ptr into the
* region must be updated since a later routine will need to perform another
* test. If the region is completely good, we end up returning the same
* last block number.
*
* Set blkno to -1 if we encounter no errors. This is an invalid block number
* since we don't ever expect logs to get this large.
*/
STATIC int
xlog_find_verify_cycle(
xlog_t *log,
xfs_daddr_t start_blk,
int nbblks,
uint stop_on_cycle_no,
xfs_daddr_t *new_blk)
{
xfs_daddr_t i, j;
uint cycle;
xfs_buf_t *bp;
xfs_daddr_t bufblks;
xfs_caddr_t buf = NULL;
int error = 0;
bufblks = 1 << ffs(nbblks);
while (!(bp = xlog_get_bp(log, bufblks))) {
/* can't get enough memory to do everything in one big buffer */
bufblks >>= 1;
if (bufblks <= log->l_sectbb_log)
return ENOMEM;
}
for (i = start_blk; i < start_blk + nbblks; i += bufblks) {
int bcount;
bcount = min(bufblks, (start_blk + nbblks - i));
if ((error = xlog_bread(log, i, bcount, bp)))
goto out;
buf = xlog_align(log, i, bcount, bp);
for (j = 0; j < bcount; j++) {
cycle = GET_CYCLE(buf, ARCH_CONVERT);
if (cycle == stop_on_cycle_no) {
*new_blk = i+j;
goto out;
}
buf += BBSIZE;
}
}
*new_blk = -1;
out:
xlog_put_bp(bp);
return error;
}
/*
* Potentially backup over partial log record write.
*
* In the typical case, last_blk is the number of the block directly after
* a good log record. Therefore, we subtract one to get the block number
* of the last block in the given buffer. extra_bblks contains the number
* of blocks we would have read on a previous read. This happens when the
* last log record is split over the end of the physical log.
*
* extra_bblks is the number of blocks potentially verified on a previous
* call to this routine.
*/
STATIC int
xlog_find_verify_log_record(
xlog_t *log,
xfs_daddr_t start_blk,
xfs_daddr_t *last_blk,
int extra_bblks)
{
xfs_daddr_t i;
xfs_buf_t *bp;
xfs_caddr_t offset = NULL;
xlog_rec_header_t *head = NULL;
int error = 0;
int smallmem = 0;
int num_blks = *last_blk - start_blk;
int xhdrs;
ASSERT(start_blk != 0 || *last_blk != start_blk);
if (!(bp = xlog_get_bp(log, num_blks))) {
if (!(bp = xlog_get_bp(log, 1)))
return ENOMEM;
smallmem = 1;
} else {
if ((error = xlog_bread(log, start_blk, num_blks, bp)))
goto out;
offset = xlog_align(log, start_blk, num_blks, bp);
offset += ((num_blks - 1) << BBSHIFT);
}
for (i = (*last_blk) - 1; i >= 0; i--) {
if (i < start_blk) {
/* valid log record not found */
xlog_warn(
"XFS: Log inconsistent (didn't find previous header)");
ASSERT(0);
error = XFS_ERROR(EIO);
goto out;
}
if (smallmem) {
if ((error = xlog_bread(log, i, 1, bp)))
goto out;
offset = xlog_align(log, i, 1, bp);
}
head = (xlog_rec_header_t *)offset;
if (XLOG_HEADER_MAGIC_NUM ==
INT_GET(head->h_magicno, ARCH_CONVERT))
break;
if (!smallmem)
offset -= BBSIZE;
}
/*
* We hit the beginning of the physical log & still no header. Return
* to caller. If caller can handle a return of -1, then this routine
* will be called again for the end of the physical log.
*/
if (i == -1) {
error = -1;
goto out;
}
/*
* We have the final block of the good log (the first block
* of the log record _before_ the head. So we check the uuid.
*/
if ((error = xlog_header_check_mount(log->l_mp, head)))
goto out;
/*
* We may have found a log record header before we expected one.
* last_blk will be the 1st block # with a given cycle #. We may end
* up reading an entire log record. In this case, we don't want to
* reset last_blk. Only when last_blk points in the middle of a log
* record do we update last_blk.
*/
if (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb)) {
uint h_size = INT_GET(head->h_size, ARCH_CONVERT);
xhdrs = h_size / XLOG_HEADER_CYCLE_SIZE;
if (h_size % XLOG_HEADER_CYCLE_SIZE)
xhdrs++;
} else {
xhdrs = 1;
}
if (*last_blk - i + extra_bblks
!= BTOBB(INT_GET(head->h_len, ARCH_CONVERT)) + xhdrs)
*last_blk = i;
out:
xlog_put_bp(bp);
return error;
}
/*
* Head is defined to be the point of the log where the next log write
* write could go. This means that incomplete LR writes at the end are
* eliminated when calculating the head. We aren't guaranteed that previous
* LR have complete transactions. We only know that a cycle number of
* current cycle number -1 won't be present in the log if we start writing
* from our current block number.
*
* last_blk contains the block number of the first block with a given
* cycle number.
*
* Return: zero if normal, non-zero if error.
*/
int
xlog_find_head(
xlog_t *log,
xfs_daddr_t *return_head_blk)
{
xfs_buf_t *bp;
xfs_caddr_t offset;
xfs_daddr_t new_blk, first_blk, start_blk, last_blk, head_blk;
int num_scan_bblks;
uint first_half_cycle, last_half_cycle;
uint stop_on_cycle;
int error, log_bbnum = log->l_logBBsize;
/* Is the end of the log device zeroed? */
if ((error = xlog_find_zeroed(log, &first_blk)) == -1) {
*return_head_blk = first_blk;
/* Is the whole lot zeroed? */
if (!first_blk) {
/* Linux XFS shouldn't generate totally zeroed logs -
* mkfs etc write a dummy unmount record to a fresh
* log so we can store the uuid in there
*/
xlog_warn("XFS: totally zeroed log");
}
return 0;
} else if (error) {
xlog_warn("XFS: empty log check failed");
return error;
}
first_blk = 0; /* get cycle # of 1st block */
bp = xlog_get_bp(log, 1);
if (!bp)
return ENOMEM;
if ((error = xlog_bread(log, 0, 1, bp)))
goto bp_err;
offset = xlog_align(log, 0, 1, bp);
first_half_cycle = GET_CYCLE(offset, ARCH_CONVERT);
last_blk = head_blk = log_bbnum - 1; /* get cycle # of last block */
if ((error = xlog_bread(log, last_blk, 1, bp)))
goto bp_err;
offset = xlog_align(log, last_blk, 1, bp);
last_half_cycle = GET_CYCLE(offset, ARCH_CONVERT);
ASSERT(last_half_cycle != 0);
/*
* If the 1st half cycle number is equal to the last half cycle number,
* then the entire log is stamped with the same cycle number. In this
* case, head_blk can't be set to zero (which makes sense). The below
* math doesn't work out properly with head_blk equal to zero. Instead,
* we set it to log_bbnum which is an invalid block number, but this
* value makes the math correct. If head_blk doesn't changed through
* all the tests below, *head_blk is set to zero at the very end rather
* than log_bbnum. In a sense, log_bbnum and zero are the same block
* in a circular file.
*/
if (first_half_cycle == last_half_cycle) {
/*
* In this case we believe that the entire log should have
* cycle number last_half_cycle. We need to scan backwards
* from the end verifying that there are no holes still
* containing last_half_cycle - 1. If we find such a hole,
* then the start of that hole will be the new head. The
* simple case looks like
* x | x ... | x - 1 | x
* Another case that fits this picture would be
* x | x + 1 | x ... | x
* In this case the head really is somwhere at the end of the
* log, as one of the latest writes at the beginning was
* incomplete.
* One more case is
* x | x + 1 | x ... | x - 1 | x
* This is really the combination of the above two cases, and
* the head has to end up at the start of the x-1 hole at the
* end of the log.
*
* In the 256k log case, we will read from the beginning to the
* end of the log and search for cycle numbers equal to x-1.
* We don't worry about the x+1 blocks that we encounter,
* because we know that they cannot be the head since the log
* started with x.
*/
head_blk = log_bbnum;
stop_on_cycle = last_half_cycle - 1;
} else {
/*
* In this case we want to find the first block with cycle
* number matching last_half_cycle. We expect the log to be
* some variation on
* x + 1 ... | x ...
* The first block with cycle number x (last_half_cycle) will
* be where the new head belongs. First we do a binary search
* for the first occurrence of last_half_cycle. The binary
* search may not be totally accurate, so then we scan back
* from there looking for occurrences of last_half_cycle before
* us. If that backwards scan wraps around the beginning of
* the log, then we look for occurrences of last_half_cycle - 1
* at the end of the log. The cases we're looking for look
* like
* x + 1 ... | x | x + 1 | x ...
* ^ binary search stopped here
* or
* x + 1 ... | x ... | x - 1 | x
* <---------> less than scan distance
*/
stop_on_cycle = last_half_cycle;
if ((error = xlog_find_cycle_start(log, bp, first_blk,
&head_blk, last_half_cycle)))
goto bp_err;
}
/*
* Now validate the answer. Scan back some number of maximum possible
* blocks and make sure each one has the expected cycle number. The
* maximum is determined by the total possible amount of buffering
* in the in-core log. The following number can be made tighter if
* we actually look at the block size of the filesystem.
*/
num_scan_bblks = XLOG_TOTAL_REC_SHIFT(log);
if (head_blk >= num_scan_bblks) {
/*
* We are guaranteed that the entire check can be performed
* in one buffer.
*/
start_blk = head_blk - num_scan_bblks;
if ((error = xlog_find_verify_cycle(log,
start_blk, num_scan_bblks,
stop_on_cycle, &new_blk)))
goto bp_err;
if (new_blk != -1)
head_blk = new_blk;
} else { /* need to read 2 parts of log */
/*
* We are going to scan backwards in the log in two parts.
* First we scan the physical end of the log. In this part
* of the log, we are looking for blocks with cycle number
* last_half_cycle - 1.
* If we find one, then we know that the log starts there, as
* we've found a hole that didn't get written in going around
* the end of the physical log. The simple case for this is
* x + 1 ... | x ... | x - 1 | x
* <---------> less than scan distance
* If all of the blocks at the end of the log have cycle number
* last_half_cycle, then we check the blocks at the start of
* the log looking for occurrences of last_half_cycle. If we
* find one, then our current estimate for the location of the
* first occurrence of last_half_cycle is wrong and we move
* back to the hole we've found. This case looks like
* x + 1 ... | x | x + 1 | x ...
* ^ binary search stopped here
* Another case we need to handle that only occurs in 256k
* logs is
* x + 1 ... | x ... | x+1 | x ...
* ^ binary search stops here
* In a 256k log, the scan at the end of the log will see the
* x + 1 blocks. We need to skip past those since that is
* certainly not the head of the log. By searching for
* last_half_cycle-1 we accomplish that.
*/
start_blk = log_bbnum - num_scan_bblks + head_blk;
ASSERT(head_blk <= INT_MAX &&
(xfs_daddr_t) num_scan_bblks - head_blk >= 0);
if ((error = xlog_find_verify_cycle(log, start_blk,
num_scan_bblks - (int)head_blk,
(stop_on_cycle - 1), &new_blk)))
goto bp_err;
if (new_blk != -1) {
head_blk = new_blk;
goto bad_blk;
}
/*
* Scan beginning of log now. The last part of the physical
* log is good. This scan needs to verify that it doesn't find
* the last_half_cycle.
*/
start_blk = 0;
ASSERT(head_blk <= INT_MAX);
if ((error = xlog_find_verify_cycle(log,
start_blk, (int)head_blk,
stop_on_cycle, &new_blk)))
goto bp_err;
if (new_blk != -1)
head_blk = new_blk;
}
bad_blk:
/*
* Now we need to make sure head_blk is not pointing to a block in
* the middle of a log record.
*/
num_scan_bblks = XLOG_REC_SHIFT(log);
if (head_blk >= num_scan_bblks) {
start_blk = head_blk - num_scan_bblks; /* don't read head_blk */
/* start ptr at last block ptr before head_blk */
if ((error = xlog_find_verify_log_record(log, start_blk,
&head_blk, 0)) == -1) {
error = XFS_ERROR(EIO);
goto bp_err;
} else if (error)
goto bp_err;
} else {
start_blk = 0;
ASSERT(head_blk <= INT_MAX);
if ((error = xlog_find_verify_log_record(log, start_blk,
&head_blk, 0)) == -1) {
/* We hit the beginning of the log during our search */
start_blk = log_bbnum - num_scan_bblks + head_blk;
new_blk = log_bbnum;
ASSERT(start_blk <= INT_MAX &&
(xfs_daddr_t) log_bbnum-start_blk >= 0);
ASSERT(head_blk <= INT_MAX);
if ((error = xlog_find_verify_log_record(log,
start_blk, &new_blk,
(int)head_blk)) == -1) {
error = XFS_ERROR(EIO);
goto bp_err;
} else if (error)
goto bp_err;
if (new_blk != log_bbnum)
head_blk = new_blk;
} else if (error)
goto bp_err;
}
xlog_put_bp(bp);
if (head_blk == log_bbnum)
*return_head_blk = 0;
else
*return_head_blk = head_blk;
/*
* When returning here, we have a good block number. Bad block
* means that during a previous crash, we didn't have a clean break
* from cycle number N to cycle number N-1. In this case, we need
* to find the first block with cycle number N-1.
*/
return 0;
bp_err:
xlog_put_bp(bp);
if (error)
xlog_warn("XFS: failed to find log head");
return error;
}
/*
* Find the sync block number or the tail of the log.
*
* This will be the block number of the last record to have its
* associated buffers synced to disk. Every log record header has
* a sync lsn embedded in it. LSNs hold block numbers, so it is easy
* to get a sync block number. The only concern is to figure out which
* log record header to believe.
*
* The following algorithm uses the log record header with the largest
* lsn. The entire log record does not need to be valid. We only care
* that the header is valid.
*
* We could speed up search by using current head_blk buffer, but it is not
* available.
*/
int
xlog_find_tail(
xlog_t *log,
xfs_daddr_t *head_blk,
xfs_daddr_t *tail_blk,
int readonly)
{
xlog_rec_header_t *rhead;
xlog_op_header_t *op_head;
xfs_caddr_t offset = NULL;
xfs_buf_t *bp;
int error, i, found;
xfs_daddr_t umount_data_blk;
xfs_daddr_t after_umount_blk;
xfs_lsn_t tail_lsn;
int hblks;
found = 0;
/*
* Find previous log record
*/
if ((error = xlog_find_head(log, head_blk)))
return error;
bp = xlog_get_bp(log, 1);
if (!bp)
return ENOMEM;
if (*head_blk == 0) { /* special case */
if ((error = xlog_bread(log, 0, 1, bp)))
goto bread_err;
offset = xlog_align(log, 0, 1, bp);
if (GET_CYCLE(offset, ARCH_CONVERT) == 0) {
*tail_blk = 0;
/* leave all other log inited values alone */
goto exit;
}
}
/*
* Search backwards looking for log record header block
*/
ASSERT(*head_blk < INT_MAX);
for (i = (int)(*head_blk) - 1; i >= 0; i--) {
if ((error = xlog_bread(log, i, 1, bp)))
goto bread_err;
offset = xlog_align(log, i, 1, bp);
if (XLOG_HEADER_MAGIC_NUM ==
INT_GET(*(uint *)offset, ARCH_CONVERT)) {
found = 1;
break;
}
}
/*
* If we haven't found the log record header block, start looking
* again from the end of the physical log. XXXmiken: There should be
* a check here to make sure we didn't search more than N blocks in
* the previous code.
*/
if (!found) {
for (i = log->l_logBBsize - 1; i >= (int)(*head_blk); i--) {
if ((error = xlog_bread(log, i, 1, bp)))
goto bread_err;
offset = xlog_align(log, i, 1, bp);
if (XLOG_HEADER_MAGIC_NUM ==
INT_GET(*(uint*)offset, ARCH_CONVERT)) {
found = 2;
break;
}
}
}
if (!found) {
xlog_warn("XFS: xlog_find_tail: couldn't find sync record");
ASSERT(0);
return XFS_ERROR(EIO);
}
/* find blk_no of tail of log */
rhead = (xlog_rec_header_t *)offset;
*tail_blk = BLOCK_LSN(rhead->h_tail_lsn, ARCH_CONVERT);
/*
* Reset log values according to the state of the log when we
* crashed. In the case where head_blk == 0, we bump curr_cycle
* one because the next write starts a new cycle rather than
* continuing the cycle of the last good log record. At this
* point we have guaranteed that all partial log records have been
* accounted for. Therefore, we know that the last good log record
* written was complete and ended exactly on the end boundary
* of the physical log.
*/
log->l_prev_block = i;
log->l_curr_block = (int)*head_blk;
log->l_curr_cycle = INT_GET(rhead->h_cycle, ARCH_CONVERT);
if (found == 2)
log->l_curr_cycle++;
log->l_tail_lsn = INT_GET(rhead->h_tail_lsn, ARCH_CONVERT);
log->l_last_sync_lsn = INT_GET(rhead->h_lsn, ARCH_CONVERT);
log->l_grant_reserve_cycle = log->l_curr_cycle;
log->l_grant_reserve_bytes = BBTOB(log->l_curr_block);
log->l_grant_write_cycle = log->l_curr_cycle;
log->l_grant_write_bytes = BBTOB(log->l_curr_block);
/*
* Look for unmount record. If we find it, then we know there
* was a clean unmount. Since 'i' could be the last block in
* the physical log, we convert to a log block before comparing
* to the head_blk.
*
* Save the current tail lsn to use to pass to
* xlog_clear_stale_blocks() below. We won't want to clear the
* unmount record if there is one, so we pass the lsn of the
* unmount record rather than the block after it.
*/
if (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb)) {
int h_size = INT_GET(rhead->h_size, ARCH_CONVERT);
int h_version = INT_GET(rhead->h_version, ARCH_CONVERT);
if ((h_version & XLOG_VERSION_2) &&
(h_size > XLOG_HEADER_CYCLE_SIZE)) {
hblks = h_size / XLOG_HEADER_CYCLE_SIZE;
if (h_size % XLOG_HEADER_CYCLE_SIZE)
hblks++;
} else {
hblks = 1;
}
} else {
hblks = 1;
}
after_umount_blk = (i + hblks + (int)
BTOBB(INT_GET(rhead->h_len, ARCH_CONVERT))) % log->l_logBBsize;
tail_lsn = log->l_tail_lsn;
if (*head_blk == after_umount_blk &&
INT_GET(rhead->h_num_logops, ARCH_CONVERT) == 1) {
umount_data_blk = (i + hblks) % log->l_logBBsize;
if ((error = xlog_bread(log, umount_data_blk, 1, bp))) {
goto bread_err;
}
offset = xlog_align(log, umount_data_blk, 1, bp);
op_head = (xlog_op_header_t *)offset;
if (op_head->oh_flags & XLOG_UNMOUNT_TRANS) {
/*
* Set tail and last sync so that newly written
* log records will point recovery to after the
* current unmount record.
*/
ASSIGN_ANY_LSN(log->l_tail_lsn, log->l_curr_cycle,
after_umount_blk, ARCH_NOCONVERT);
ASSIGN_ANY_LSN(log->l_last_sync_lsn, log->l_curr_cycle,
after_umount_blk, ARCH_NOCONVERT);
*tail_blk = after_umount_blk;
}
}
/*
* Make sure that there are no blocks in front of the head
* with the same cycle number as the head. This can happen
* because we allow multiple outstanding log writes concurrently,
* and the later writes might make it out before earlier ones.
*
* We use the lsn from before modifying it so that we'll never
* overwrite the unmount record after a clean unmount.
*
* Do this only if we are going to recover the filesystem
*
* NOTE: This used to say "if (!readonly)"
* However on Linux, we can & do recover a read-only filesystem.
* We only skip recovery if NORECOVERY is specified on mount,
* in which case we would not be here.
*
* But... if the -device- itself is readonly, just skip this.
* We can't recover this device anyway, so it won't matter.
*/
if (!xfs_readonly_buftarg(log->l_mp->m_logdev_targp)) {
error = xlog_clear_stale_blocks(log, tail_lsn);
}
bread_err:
exit:
xlog_put_bp(bp);
if (error)
xlog_warn("XFS: failed to locate log tail");
return error;
}
/*
* Is the log zeroed at all?
*
* The last binary search should be changed to perform an X block read
* once X becomes small enough. You can then search linearly through
* the X blocks. This will cut down on the number of reads we need to do.
*
* If the log is partially zeroed, this routine will pass back the blkno
* of the first block with cycle number 0. It won't have a complete LR
* preceding it.
*
* Return:
* 0 => the log is completely written to
* -1 => use *blk_no as the first block of the log
* >0 => error has occurred
*/
int
xlog_find_zeroed(
xlog_t *log,
xfs_daddr_t *blk_no)
{
xfs_buf_t *bp;
xfs_caddr_t offset;
uint first_cycle, last_cycle;
xfs_daddr_t new_blk, last_blk, start_blk;
xfs_daddr_t num_scan_bblks;
int error, log_bbnum = log->l_logBBsize;
/* check totally zeroed log */
bp = xlog_get_bp(log, 1);
if (!bp)
return ENOMEM;
if ((error = xlog_bread(log, 0, 1, bp)))
goto bp_err;
offset = xlog_align(log, 0, 1, bp);
first_cycle = GET_CYCLE(offset, ARCH_CONVERT);
if (first_cycle == 0) { /* completely zeroed log */
*blk_no = 0;
xlog_put_bp(bp);
return -1;
}
/* check partially zeroed log */
if ((error = xlog_bread(log, log_bbnum-1, 1, bp)))
goto bp_err;
offset = xlog_align(log, log_bbnum-1, 1, bp);
last_cycle = GET_CYCLE(offset, ARCH_CONVERT);
if (last_cycle != 0) { /* log completely written to */
xlog_put_bp(bp);
return 0;
} else if (first_cycle != 1) {
/*
* If the cycle of the last block is zero, the cycle of
* the first block must be 1. If it's not, maybe we're
* not looking at a log... Bail out.
*/
xlog_warn("XFS: Log inconsistent or not a log (last==0, first!=1)");
return XFS_ERROR(EINVAL);
}
/* we have a partially zeroed log */
last_blk = log_bbnum-1;
if ((error = xlog_find_cycle_start(log, bp, 0, &last_blk, 0)))
goto bp_err;
/*
* Validate the answer. Because there is no way to guarantee that
* the entire log is made up of log records which are the same size,
* we scan over the defined maximum blocks. At this point, the maximum
* is not chosen to mean anything special. XXXmiken
*/
num_scan_bblks = XLOG_TOTAL_REC_SHIFT(log);
ASSERT(num_scan_bblks <= INT_MAX);
if (last_blk < num_scan_bblks)
num_scan_bblks = last_blk;
start_blk = last_blk - num_scan_bblks;
/*
* We search for any instances of cycle number 0 that occur before
* our current estimate of the head. What we're trying to detect is
* 1 ... | 0 | 1 | 0...
* ^ binary search ends here
*/
if ((error = xlog_find_verify_cycle(log, start_blk,
(int)num_scan_bblks, 0, &new_blk)))
goto bp_err;
if (new_blk != -1)
last_blk = new_blk;
/*
* Potentially backup over partial log record write. We don't need
* to search the end of the log because we know it is zero.
*/
if ((error = xlog_find_verify_log_record(log, start_blk,
&last_blk, 0)) == -1) {
error = XFS_ERROR(EIO);
goto bp_err;
} else if (error)
goto bp_err;
*blk_no = last_blk;
bp_err:
xlog_put_bp(bp);
if (error)
return error;
return -1;
}
STATIC void
xlog_unpack_data(
xlog_rec_header_t *rhead,
xfs_caddr_t dp,
xlog_t *log)
{
int i, j, k;
xlog_in_core_2_t *xhdr;
for (i = 0; i < BTOBB(INT_GET(rhead->h_len, ARCH_CONVERT)) &&
i < (XLOG_HEADER_CYCLE_SIZE / BBSIZE); i++) {
*(uint *)dp = *(uint *)&rhead->h_cycle_data[i];
dp += BBSIZE;
}
if (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb)) {
xhdr = (xlog_in_core_2_t *)rhead;
for ( ; i < BTOBB(INT_GET(rhead->h_len, ARCH_CONVERT)); i++) {
j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
*(uint *)dp = xhdr[j].hic_xheader.xh_cycle_data[k];
dp += BBSIZE;
}
}
xlog_unpack_data_checksum(rhead, dp, log);
}
STATIC xlog_recover_t *
xlog_recover_find_tid(
xlog_recover_t *q,
xlog_tid_t tid)
{
xlog_recover_t *p = q;
while (p != NULL) {
if (p->r_log_tid == tid)
break;
p = p->r_next;
}
return p;
}
STATIC void
xlog_recover_put_hashq(
xlog_recover_t **q,
xlog_recover_t *trans)
{
trans->r_next = *q;
*q = trans;
}
STATIC void
xlog_recover_new_tid(
xlog_recover_t **q,
xlog_tid_t tid,
xfs_lsn_t lsn)
{
xlog_recover_t *trans;
trans = kmem_zalloc(sizeof(xlog_recover_t), KM_SLEEP);
trans->r_log_tid = tid;
trans->r_lsn = lsn;
xlog_recover_put_hashq(q, trans);
}
STATIC int
xlog_recover_unlink_tid(
xlog_recover_t **q,
xlog_recover_t *trans)
{
xlog_recover_t *tp;
int found = 0;
ASSERT(trans != 0);
if (trans == *q) {
*q = (*q)->r_next;
} else {
tp = *q;
while (tp != 0) {
if (tp->r_next == trans) {
found = 1;
break;
}
tp = tp->r_next;
}
if (!found) {
xlog_warn(
"XFS: xlog_recover_unlink_tid: trans not found");
ASSERT(0);
return XFS_ERROR(EIO);
}
tp->r_next = tp->r_next->r_next;
}
return 0;
}
/*
* Free up any resources allocated by the transaction
*
* Remember that EFIs, EFDs, and IUNLINKs are handled later.
*/
STATIC void
xlog_recover_free_trans(
xlog_recover_t *trans)
{
xlog_recover_item_t *first_item, *item, *free_item;
int i;
item = first_item = trans->r_itemq;
do {
free_item = item;
item = item->ri_next;
/* Free the regions in the item. */
for (i = 0; i < free_item->ri_cnt; i++) {
kmem_free(free_item->ri_buf[i].i_addr,
free_item->ri_buf[i].i_len);
}
/* Free the item itself */
kmem_free(free_item->ri_buf,
(free_item->ri_total * sizeof(xfs_log_iovec_t)));
kmem_free(free_item, sizeof(xlog_recover_item_t));
} while (first_item != item);
/* Free the transaction recover structure */
kmem_free(trans, sizeof(xlog_recover_t));
}
STATIC int
xlog_recover_commit_trans(
xlog_t *log,
xlog_recover_t **q,
xlog_recover_t *trans,
int pass)
{
int error;
if ((error = xlog_recover_unlink_tid(q, trans)))
return error;
if ((error = xlog_recover_do_trans(log, trans, pass)))
return error;
xlog_recover_free_trans(trans); /* no error */
return 0;
}
STATIC void
xlog_recover_insert_item_backq(
xlog_recover_item_t **q,
xlog_recover_item_t *item)
{
if (*q == 0) {
item->ri_prev = item->ri_next = item;
*q = item;
} else {
item->ri_next = *q;
item->ri_prev = (*q)->ri_prev;
(*q)->ri_prev = item;
item->ri_prev->ri_next = item;
}
}
STATIC void
xlog_recover_add_item(
xlog_recover_item_t **itemq)
{
xlog_recover_item_t *item;
item = kmem_zalloc(sizeof(xlog_recover_item_t), KM_SLEEP);
xlog_recover_insert_item_backq(itemq, item);
}
STATIC int
xlog_recover_add_to_cont_trans(
xlog_recover_t *trans,
xfs_caddr_t dp,
int len)
{
xlog_recover_item_t *item;
xfs_caddr_t ptr, old_ptr;
int old_len;
item = trans->r_itemq;
if (item == 0) {
/* finish copying rest of trans header */
xlog_recover_add_item(&trans->r_itemq);
ptr = (xfs_caddr_t) &trans->r_theader +
sizeof(xfs_trans_header_t) - len;
memcpy(ptr, dp, len); /* d, s, l */
return 0;
}
item = item->ri_prev;
old_ptr = item->ri_buf[item->ri_cnt-1].i_addr;
old_len = item->ri_buf[item->ri_cnt-1].i_len;
ptr = kmem_realloc(old_ptr, len+old_len, old_len, 0);
memcpy(&ptr[old_len], dp, len); /* d, s, l */
item->ri_buf[item->ri_cnt-1].i_len += len;
item->ri_buf[item->ri_cnt-1].i_addr = ptr;
return 0;
}
/*
* The next region to add is the start of a new region. It could be
* a whole region or it could be the first part of a new region. Because
* of this, the assumption here is that the type and size fields of all
* format structures fit into the first 32 bits of the structure.
*
* This works because all regions must be 32 bit aligned. Therefore, we
* either have both fields or we have neither field. In the case we have
* neither field, the data part of the region is zero length. We only have
* a log_op_header and can throw away the header since a new one will appear
* later. If we have at least 4 bytes, then we can determine how many regions
* will appear in the current log item.
*/
STATIC int
xlog_recover_add_to_trans(
xlog_recover_t *trans,
xfs_caddr_t dp,
int len)
{
xfs_inode_log_format_t *in_f; /* any will do */
xlog_recover_item_t *item;
xfs_caddr_t ptr;
if (!len)
return 0;
item = trans->r_itemq;
if (item == 0) {
ASSERT(*(uint *)dp == XFS_TRANS_HEADER_MAGIC);
if (len == sizeof(xfs_trans_header_t))
xlog_recover_add_item(&trans->r_itemq);
memcpy(&trans->r_theader, dp, len); /* d, s, l */
return 0;
}
ptr = kmem_alloc(len, KM_SLEEP);
memcpy(ptr, dp, len);
in_f = (xfs_inode_log_format_t *)ptr;
if (item->ri_prev->ri_total != 0 &&
item->ri_prev->ri_total == item->ri_prev->ri_cnt) {
xlog_recover_add_item(&trans->r_itemq);
}
item = trans->r_itemq;
item = item->ri_prev;
if (item->ri_total == 0) { /* first region to be added */
item->ri_total = in_f->ilf_size;
ASSERT(item->ri_total <= XLOG_MAX_REGIONS_IN_ITEM);
item->ri_buf = kmem_zalloc((item->ri_total *
sizeof(xfs_log_iovec_t)), KM_SLEEP);
}
ASSERT(item->ri_total > item->ri_cnt);
/* Description region is ri_buf[0] */
item->ri_buf[item->ri_cnt].i_addr = ptr;
item->ri_buf[item->ri_cnt].i_len = len;
item->ri_cnt++;
return 0;
}
STATIC int
xlog_recover_unmount_trans(
xlog_recover_t *trans)
{
/* Do nothing now */
xlog_warn("XFS: xlog_recover_unmount_trans: Unmount LR");
return 0;
}
/*
* There are two valid states of the r_state field. 0 indicates that the
* transaction structure is in a normal state. We have either seen the
* start of the transaction or the last operation we added was not a partial
* operation. If the last operation we added to the transaction was a
* partial operation, we need to mark r_state with XLOG_WAS_CONT_TRANS.
*
* NOTE: skip LRs with 0 data length.
*/
STATIC int
xlog_recover_process_data(
xlog_t *log,
xlog_recover_t *rhash[],
xlog_rec_header_t *rhead,
xfs_caddr_t dp,
int pass)
{
xfs_caddr_t lp;
int num_logops;
xlog_op_header_t *ohead;
xlog_recover_t *trans;
xlog_tid_t tid;
int error;
unsigned long hash;
uint flags;
lp = dp + INT_GET(rhead->h_len, ARCH_CONVERT);
num_logops = INT_GET(rhead->h_num_logops, ARCH_CONVERT);
/* check the log format matches our own - else we can't recover */
if (xlog_header_check_recover(log->l_mp, rhead))
return (XFS_ERROR(EIO));
while ((dp < lp) && num_logops) {
ASSERT(dp + sizeof(xlog_op_header_t) <= lp);
ohead = (xlog_op_header_t *)dp;
dp += sizeof(xlog_op_header_t);
if (ohead->oh_clientid != XFS_TRANSACTION &&
ohead->oh_clientid != XFS_LOG) {
xlog_warn(
"XFS: xlog_recover_process_data: bad clientid");
ASSERT(0);
return (XFS_ERROR(EIO));
}
tid = INT_GET(ohead->oh_tid, ARCH_CONVERT);
hash = XLOG_RHASH(tid);
trans = xlog_recover_find_tid(rhash[hash], tid);
if (trans == NULL) { /* not found; add new tid */
if (ohead->oh_flags & XLOG_START_TRANS)
xlog_recover_new_tid(&rhash[hash], tid,
INT_GET(rhead->h_lsn, ARCH_CONVERT));
} else {
ASSERT(dp+INT_GET(ohead->oh_len, ARCH_CONVERT) <= lp);
flags = ohead->oh_flags & ~XLOG_END_TRANS;
if (flags & XLOG_WAS_CONT_TRANS)
flags &= ~XLOG_CONTINUE_TRANS;
switch (flags) {
case XLOG_COMMIT_TRANS:
error = xlog_recover_commit_trans(log,
&rhash[hash], trans, pass);
break;
case XLOG_UNMOUNT_TRANS:
error = xlog_recover_unmount_trans(trans);
break;
case XLOG_WAS_CONT_TRANS:
error = xlog_recover_add_to_cont_trans(trans,
dp, INT_GET(ohead->oh_len,
ARCH_CONVERT));
break;
case XLOG_START_TRANS:
xlog_warn(
"XFS: xlog_recover_process_data: bad transaction");
ASSERT(0);
error = XFS_ERROR(EIO);
break;
case 0:
case XLOG_CONTINUE_TRANS:
error = xlog_recover_add_to_trans(trans,
dp, INT_GET(ohead->oh_len,
ARCH_CONVERT));
break;
default:
xlog_warn(
"XFS: xlog_recover_process_data: bad flag");
ASSERT(0);
error = XFS_ERROR(EIO);
break;
}
if (error)
return error;
}
dp += INT_GET(ohead->oh_len, ARCH_CONVERT);
num_logops--;
}
return 0;
}
STATIC int
xlog_valid_rec_header(
xlog_t *log,
xlog_rec_header_t *rhead,
xfs_daddr_t blkno)
{
int hlen;
if (unlikely(
(INT_GET(rhead->h_magicno, ARCH_CONVERT) !=
XLOG_HEADER_MAGIC_NUM))) {
XFS_ERROR_REPORT("xlog_valid_rec_header(1)",
XFS_ERRLEVEL_LOW, log->l_mp);
return XFS_ERROR(EFSCORRUPTED);
}
if (unlikely(
(INT_ISZERO(rhead->h_version, ARCH_CONVERT) ||
(INT_GET(rhead->h_version, ARCH_CONVERT) &
(~XLOG_VERSION_OKBITS)) != 0))) {
xlog_warn("XFS: %s: unrecognised log version (%d).",
__FUNCTION__, INT_GET(rhead->h_version, ARCH_CONVERT));
return XFS_ERROR(EIO);
}
/* LR body must have data or it wouldn't have been written */
hlen = INT_GET(rhead->h_len, ARCH_CONVERT);
if (unlikely( hlen <= 0 || hlen > INT_MAX )) {
XFS_ERROR_REPORT("xlog_valid_rec_header(2)",
XFS_ERRLEVEL_LOW, log->l_mp);
return XFS_ERROR(EFSCORRUPTED);
}
if (unlikely( blkno > log->l_logBBsize || blkno > INT_MAX )) {
XFS_ERROR_REPORT("xlog_valid_rec_header(3)",
XFS_ERRLEVEL_LOW, log->l_mp);
return XFS_ERROR(EFSCORRUPTED);
}
return 0;
}
/*
* Read the log from tail to head and process the log records found.
* Handle the two cases where the tail and head are in the same cycle
* and where the active portion of the log wraps around the end of
* the physical log separately. The pass parameter is passed through
* to the routines called to process the data and is not looked at
* here.
*/
int
xlog_do_recovery_pass(
xlog_t *log,
xfs_daddr_t head_blk,
xfs_daddr_t tail_blk,
int pass)
{
xlog_rec_header_t *rhead;
xfs_daddr_t blk_no;
xfs_caddr_t bufaddr, offset;
xfs_buf_t *hbp, *dbp;
int error = 0, h_size;
int bblks, split_bblks;
int hblks, split_hblks, wrapped_hblks;
xlog_recover_t *rhash[XLOG_RHASH_SIZE];
ASSERT(head_blk != tail_blk);
/*
* Read the header of the tail block and get the iclog buffer size from
* h_size. Use this to tell how many sectors make up the log header.
*/
if (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb)) {
/*
* When using variable length iclogs, read first sector of
* iclog header and extract the header size from it. Get a
* new hbp that is the correct size.
*/
hbp = xlog_get_bp(log, 1);
if (!hbp)
return ENOMEM;
if ((error = xlog_bread(log, tail_blk, 1, hbp)))
goto bread_err1;
offset = xlog_align(log, tail_blk, 1, hbp);
rhead = (xlog_rec_header_t *)offset;
error = xlog_valid_rec_header(log, rhead, tail_blk);
if (error)
goto bread_err1;
h_size = INT_GET(rhead->h_size, ARCH_CONVERT);
if ((INT_GET(rhead->h_version, ARCH_CONVERT)
& XLOG_VERSION_2) &&
(h_size > XLOG_HEADER_CYCLE_SIZE)) {
hblks = h_size / XLOG_HEADER_CYCLE_SIZE;
if (h_size % XLOG_HEADER_CYCLE_SIZE)
hblks++;
xlog_put_bp(hbp);
hbp = xlog_get_bp(log, hblks);
} else {
hblks = 1;
}
} else {
ASSERT(log->l_sectbb_log == 0);
hblks = 1;
hbp = xlog_get_bp(log, 1);
h_size = XLOG_BIG_RECORD_BSIZE;
}
if (!hbp)
return ENOMEM;
dbp = xlog_get_bp(log, BTOBB(h_size));
if (!dbp) {
xlog_put_bp(hbp);
return ENOMEM;
}
memset(rhash, 0, sizeof(rhash));
if (tail_blk <= head_blk) {
for (blk_no = tail_blk; blk_no < head_blk; ) {
if ((error = xlog_bread(log, blk_no, hblks, hbp)))
goto bread_err2;
offset = xlog_align(log, blk_no, hblks, hbp);
rhead = (xlog_rec_header_t *)offset;
error = xlog_valid_rec_header(log, rhead, blk_no);
if (error)
goto bread_err2;
/* blocks in data section */
bblks = (int)BTOBB(INT_GET(rhead->h_len, ARCH_CONVERT));
error = xlog_bread(log, blk_no + hblks, bblks, dbp);
if (error)
goto bread_err2;
offset = xlog_align(log, blk_no + hblks, bblks, dbp);
xlog_unpack_data(rhead, offset, log);
if ((error = xlog_recover_process_data(log,
rhash, rhead, offset, pass)))
goto bread_err2;
blk_no += bblks + hblks;
}
} else {
/*
* Perform recovery around the end of the physical log.
* When the head is not on the same cycle number as the tail,
* we can't do a sequential recovery as above.
*/
blk_no = tail_blk;
while (blk_no < log->l_logBBsize) {
/*
* Check for header wrapping around physical end-of-log
*/
offset = NULL;
split_hblks = 0;
wrapped_hblks = 0;
if (blk_no + hblks <= log->l_logBBsize) {
/* Read header in one read */
error = xlog_bread(log, blk_no, hblks, hbp);
if (error)
goto bread_err2;
offset = xlog_align(log, blk_no, hblks, hbp);
} else {
/* This LR is split across physical log end */
if (blk_no != log->l_logBBsize) {
/* some data before physical log end */
ASSERT(blk_no <= INT_MAX);
split_hblks = log->l_logBBsize - (int)blk_no;
ASSERT(split_hblks > 0);
if ((error = xlog_bread(log, blk_no,
split_hblks, hbp)))
goto bread_err2;
offset = xlog_align(log, blk_no,
split_hblks, hbp);
}
/*
* Note: this black magic still works with
* large sector sizes (non-512) only because:
* - we increased the buffer size originally
* by 1 sector giving us enough extra space
* for the second read;
* - the log start is guaranteed to be sector
* aligned;
* - we read the log end (LR header start)
* _first_, then the log start (LR header end)
* - order is important.
*/
bufaddr = XFS_BUF_PTR(hbp);
XFS_BUF_SET_PTR(hbp,
bufaddr + BBTOB(split_hblks),
BBTOB(hblks - split_hblks));
wrapped_hblks = hblks - split_hblks;
error = xlog_bread(log, 0, wrapped_hblks, hbp);
if (error)
goto bread_err2;
XFS_BUF_SET_PTR(hbp, bufaddr, BBTOB(hblks));
if (!offset)
offset = xlog_align(log, 0,
wrapped_hblks, hbp);
}
rhead = (xlog_rec_header_t *)offset;
error = xlog_valid_rec_header(log, rhead,
split_hblks ? blk_no : 0);
if (error)
goto bread_err2;
bblks = (int)BTOBB(INT_GET(rhead->h_len, ARCH_CONVERT));
blk_no += hblks;
/* Read in data for log record */
if (blk_no + bblks <= log->l_logBBsize) {
error = xlog_bread(log, blk_no, bblks, dbp);
if (error)
goto bread_err2;
offset = xlog_align(log, blk_no, bblks, dbp);
} else {
/* This log record is split across the
* physical end of log */
offset = NULL;
split_bblks = 0;
if (blk_no != log->l_logBBsize) {
/* some data is before the physical
* end of log */
ASSERT(!wrapped_hblks);
ASSERT(blk_no <= INT_MAX);
split_bblks =
log->l_logBBsize - (int)blk_no;
ASSERT(split_bblks > 0);
if ((error = xlog_bread(log, blk_no,
split_bblks, dbp)))
goto bread_err2;
offset = xlog_align(log, blk_no,
split_bblks, dbp);
}
/*
* Note: this black magic still works with
* large sector sizes (non-512) only because:
* - we increased the buffer size originally
* by 1 sector giving us enough extra space
* for the second read;
* - the log start is guaranteed to be sector
* aligned;
* - we read the log end (LR header start)
* _first_, then the log start (LR header end)
* - order is important.
*/
bufaddr = XFS_BUF_PTR(dbp);
XFS_BUF_SET_PTR(dbp,
bufaddr + BBTOB(split_bblks),
BBTOB(bblks - split_bblks));
if ((error = xlog_bread(log, wrapped_hblks,
bblks - split_bblks, dbp)))
goto bread_err2;
XFS_BUF_SET_PTR(dbp, bufaddr, h_size);
if (!offset)
offset = xlog_align(log, wrapped_hblks,
bblks - split_bblks, dbp);
}
xlog_unpack_data(rhead, offset, log);
if ((error = xlog_recover_process_data(log, rhash,
rhead, offset, pass)))
goto bread_err2;
blk_no += bblks;
}
ASSERT(blk_no >= log->l_logBBsize);
blk_no -= log->l_logBBsize;
/* read first part of physical log */
while (blk_no < head_blk) {
if ((error = xlog_bread(log, blk_no, hblks, hbp)))
goto bread_err2;
offset = xlog_align(log, blk_no, hblks, hbp);
rhead = (xlog_rec_header_t *)offset;
error = xlog_valid_rec_header(log, rhead, blk_no);
if (error)
goto bread_err2;
bblks = (int)BTOBB(INT_GET(rhead->h_len, ARCH_CONVERT));
if ((error = xlog_bread(log, blk_no+hblks, bblks, dbp)))
goto bread_err2;
offset = xlog_align(log, blk_no+hblks, bblks, dbp);
xlog_unpack_data(rhead, offset, log);
if ((error = xlog_recover_process_data(log, rhash,
rhead, offset, pass)))
goto bread_err2;
blk_no += bblks + hblks;
}
}
bread_err2:
xlog_put_bp(dbp);
bread_err1:
xlog_put_bp(hbp);
return error;
}
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