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xfs: introduce new internal log vector structure
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The current log IO vector structure is a flat array and not
extensible. To make it possible to keep separate log IO vectors for
individual log items, we need a method of chaining log IO vectors
together.

Introduce a new log vector type that can be used to wrap the
existing log IO vectors on use that internally to the log. This
means that the existing external interface (xfs_log_write) does not
change and hence no changes to the transaction commit code are
required.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
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Dave Chinner authored and Alex Elder committed May 19, 2010
1 parent 99428ad commit 55b6633
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Showing 2 changed files with 90 additions and 59 deletions.
143 changes: 84 additions & 59 deletions fs/xfs/xfs_log.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -50,7 +50,7 @@ kmem_zone_t *xfs_log_ticket_zone;
(off) += (bytes);}

/* Local miscellaneous function prototypes */
STATIC int xlog_commit_record(xfs_mount_t *mp, xlog_ticket_t *ticket,
STATIC int xlog_commit_record(struct log *log, struct xlog_ticket *ticket,
xlog_in_core_t **, xfs_lsn_t *);
STATIC xlog_t * xlog_alloc_log(xfs_mount_t *mp,
xfs_buftarg_t *log_target,
Expand All @@ -59,11 +59,9 @@ STATIC xlog_t * xlog_alloc_log(xfs_mount_t *mp,
STATIC int xlog_space_left(xlog_t *log, int cycle, int bytes);
STATIC int xlog_sync(xlog_t *log, xlog_in_core_t *iclog);
STATIC void xlog_dealloc_log(xlog_t *log);
STATIC int xlog_write(xfs_mount_t *mp, xfs_log_iovec_t region[],
int nentries, struct xlog_ticket *tic,
xfs_lsn_t *start_lsn,
xlog_in_core_t **commit_iclog,
uint flags);
STATIC int xlog_write(struct log *log, struct xfs_log_vec *log_vector,
struct xlog_ticket *tic, xfs_lsn_t *start_lsn,
xlog_in_core_t **commit_iclog, uint flags);

/* local state machine functions */
STATIC void xlog_state_done_syncing(xlog_in_core_t *iclog, int);
Expand Down Expand Up @@ -258,7 +256,7 @@ xfs_log_done(
* If we get an error, just continue and give back the log ticket.
*/
(((ticket->t_flags & XLOG_TIC_INITED) == 0) &&
(xlog_commit_record(mp, ticket, iclog, &lsn)))) {
(xlog_commit_record(log, ticket, iclog, &lsn)))) {
lsn = (xfs_lsn_t) -1;
if (ticket->t_flags & XLOG_TIC_PERM_RESERV) {
flags |= XFS_LOG_REL_PERM_RESERV;
Expand Down Expand Up @@ -516,18 +514,10 @@ xfs_log_unmount_write(xfs_mount_t *mp)
#ifdef DEBUG
xlog_in_core_t *first_iclog;
#endif
xfs_log_iovec_t reg[1];
xlog_ticket_t *tic = NULL;
xfs_lsn_t lsn;
int error;

/* the data section must be 32 bit size aligned */
struct {
__uint16_t magic;
__uint16_t pad1;
__uint32_t pad2; /* may as well make it 64 bits */
} magic = { XLOG_UNMOUNT_TYPE, 0, 0 };

/*
* Don't write out unmount record on read-only mounts.
* Or, if we are doing a forced umount (typically because of IO errors).
Expand All @@ -549,16 +539,30 @@ xfs_log_unmount_write(xfs_mount_t *mp)
} while (iclog != first_iclog);
#endif
if (! (XLOG_FORCED_SHUTDOWN(log))) {
reg[0].i_addr = (void*)&magic;
reg[0].i_len = sizeof(magic);
reg[0].i_type = XLOG_REG_TYPE_UNMOUNT;

error = xfs_log_reserve(mp, 600, 1, &tic,
XFS_LOG, 0, XLOG_UNMOUNT_REC_TYPE);
if (!error) {
/* the data section must be 32 bit size aligned */
struct {
__uint16_t magic;
__uint16_t pad1;
__uint32_t pad2; /* may as well make it 64 bits */
} magic = {
.magic = XLOG_UNMOUNT_TYPE,
};
struct xfs_log_iovec reg = {
.i_addr = (void *)&magic,
.i_len = sizeof(magic),
.i_type = XLOG_REG_TYPE_UNMOUNT,
};
struct xfs_log_vec vec = {
.lv_niovecs = 1,
.lv_iovecp = &reg,
};

/* remove inited flag */
((xlog_ticket_t *)tic)->t_flags = 0;
error = xlog_write(mp, reg, 1, tic, &lsn,
tic->t_flags = 0;
error = xlog_write(log, &vec, tic, &lsn,
NULL, XLOG_UNMOUNT_TRANS);
/*
* At this point, we're umounting anyway,
Expand Down Expand Up @@ -679,11 +683,15 @@ xfs_log_write(
{
struct log *log = mp->m_log;
int error;
struct xfs_log_vec vec = {
.lv_niovecs = nentries,
.lv_iovecp = reg,
};

if (XLOG_FORCED_SHUTDOWN(log))
return XFS_ERROR(EIO);

error = xlog_write(mp, reg, nentries, tic, start_lsn, NULL, 0);
error = xlog_write(log, &vec, tic, start_lsn, NULL, 0);
if (error)
xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
return error;
Expand Down Expand Up @@ -1190,26 +1198,31 @@ xlog_alloc_log(xfs_mount_t *mp,
* ticket. Return the lsn of the commit record.
*/
STATIC int
xlog_commit_record(xfs_mount_t *mp,
xlog_ticket_t *ticket,
xlog_in_core_t **iclog,
xfs_lsn_t *commitlsnp)
xlog_commit_record(
struct log *log,
struct xlog_ticket *ticket,
struct xlog_in_core **iclog,
xfs_lsn_t *commitlsnp)
{
int error;
xfs_log_iovec_t reg[1];

reg[0].i_addr = NULL;
reg[0].i_len = 0;
reg[0].i_type = XLOG_REG_TYPE_COMMIT;
struct xfs_mount *mp = log->l_mp;
int error;
struct xfs_log_iovec reg = {
.i_addr = NULL,
.i_len = 0,
.i_type = XLOG_REG_TYPE_COMMIT,
};
struct xfs_log_vec vec = {
.lv_niovecs = 1,
.lv_iovecp = &reg,
};

ASSERT_ALWAYS(iclog);
if ((error = xlog_write(mp, reg, 1, ticket, commitlsnp,
iclog, XLOG_COMMIT_TRANS))) {
error = xlog_write(log, &vec, ticket, commitlsnp, iclog,
XLOG_COMMIT_TRANS);
if (error)
xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
}
return error;
} /* xlog_commit_record */

}

/*
* Push on the buffer cache code if we ever use more than 75% of the on-disk
Expand Down Expand Up @@ -1636,9 +1649,9 @@ xlog_print_tic_res(xfs_mount_t *mp, xlog_ticket_t *ticket)
static int
xlog_write_calc_vec_length(
struct xlog_ticket *ticket,
struct xfs_log_iovec reg[],
int nentries)
struct xfs_log_vec *log_vector)
{
struct xfs_log_vec *lv;
int headers = 0;
int len = 0;
int i;
Expand All @@ -1647,12 +1660,15 @@ xlog_write_calc_vec_length(
if (ticket->t_flags & XLOG_TIC_INITED)
headers++;

for (i = 0; i < nentries; i++) {
/* each region gets >= 1 */
headers++;
for (lv = log_vector; lv; lv = lv->lv_next) {
headers += lv->lv_niovecs;

for (i = 0; i < lv->lv_niovecs; i++) {
struct xfs_log_iovec *vecp = &lv->lv_iovecp[i];

len += reg[i].i_len;
xlog_tic_add_region(ticket, reg[i].i_len, reg[i].i_type);
len += vecp->i_len;
xlog_tic_add_region(ticket, vecp->i_len, vecp->i_type);
}
}

ticket->t_res_num_ophdrs += headers;
Expand Down Expand Up @@ -1858,16 +1874,16 @@ xlog_write_copy_finish(
*/
STATIC int
xlog_write(
struct xfs_mount *mp,
struct xfs_log_iovec reg[],
int nentries,
struct log *log,
struct xfs_log_vec *log_vector,
struct xlog_ticket *ticket,
xfs_lsn_t *start_lsn,
struct xlog_in_core **commit_iclog,
uint flags)
{
struct log *log = mp->m_log;
struct xlog_in_core *iclog = NULL;
struct xfs_log_iovec *vecp;
struct xfs_log_vec *lv;
int len;
int index;
int partial_copy = 0;
Expand All @@ -1879,25 +1895,28 @@ xlog_write(

*start_lsn = 0;

len = xlog_write_calc_vec_length(ticket, reg, nentries);
len = xlog_write_calc_vec_length(ticket, log_vector);
if (ticket->t_curr_res < len) {
xlog_print_tic_res(mp, ticket);
xlog_print_tic_res(log->l_mp, ticket);
#ifdef DEBUG
xlog_panic(
"xfs_log_write: reservation ran out. Need to up reservation");
#else
/* Customer configurable panic */
xfs_cmn_err(XFS_PTAG_LOGRES, CE_ALERT, mp,
xfs_cmn_err(XFS_PTAG_LOGRES, CE_ALERT, log->l_mp,
"xfs_log_write: reservation ran out. Need to up reservation");

/* If we did not panic, shutdown the filesystem */
xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
xfs_force_shutdown(log->l_mp, SHUTDOWN_CORRUPT_INCORE);
#endif
}

ticket->t_curr_res -= len;

for (index = 0; index < nentries; ) {
index = 0;
lv = log_vector;
vecp = lv->lv_iovecp;
while (lv && index < lv->lv_niovecs) {
__psint_t ptr;
int log_offset;

Expand All @@ -1917,13 +1936,14 @@ xlog_write(
* This loop writes out as many regions as can fit in the amount
* of space which was allocated by xlog_state_get_iclog_space().
*/
while (index < nentries) {
while (lv && index < lv->lv_niovecs) {
struct xfs_log_iovec *reg = &vecp[index];
struct xlog_op_header *ophdr;
int start_rec_copy;
int copy_len;
int copy_off;

ASSERT(reg[index].i_len % sizeof(__int32_t) == 0);
ASSERT(reg->i_len % sizeof(__int32_t) == 0);
ASSERT((__psint_t)ptr % sizeof(__int32_t) == 0);

start_rec_copy = xlog_write_start_rec(ptr, ticket);
Expand All @@ -1942,15 +1962,15 @@ xlog_write(

len += xlog_write_setup_copy(ticket, ophdr,
iclog->ic_size-log_offset,
reg[index].i_len,
reg->i_len,
&copy_off, &copy_len,
&partial_copy,
&partial_copy_len);
xlog_verify_dest_ptr(log, ptr);

/* copy region */
ASSERT(copy_len >= 0);
memcpy((xfs_caddr_t)ptr, reg[index].i_addr + copy_off,
memcpy((xfs_caddr_t)ptr, reg->i_addr + copy_off,
copy_len);
xlog_write_adv_cnt(ptr, len, log_offset, copy_len);

Expand Down Expand Up @@ -1982,9 +2002,14 @@ xlog_write(
if (partial_copy)
break;

index++;
if (++index == lv->lv_niovecs) {
lv = lv->lv_next;
index = 0;
if (lv)
vecp = lv->lv_iovecp;
}
if (record_cnt == 0) {
if (index == nentries)
if (!lv)
return 0;
break;
}
Expand Down
6 changes: 6 additions & 0 deletions fs/xfs/xfs_log.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -110,6 +110,12 @@ typedef struct xfs_log_iovec {
uint i_type; /* type of region */
} xfs_log_iovec_t;

struct xfs_log_vec {
struct xfs_log_vec *lv_next; /* next lv in build list */
int lv_niovecs; /* number of iovecs in lv */
struct xfs_log_iovec *lv_iovecp; /* iovec array */
};

/*
* Structure used to pass callback function and the function's argument
* to the log manager.
Expand Down

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