linux/fs/xfs/xfs_trans_item.c
Jesper Juhl 014c2544e6 return statement cleanup - kill pointless parentheses
This patch removes pointless parentheses from return statements.

Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-01-15 02:37:08 +01:00

538 lines
13 KiB
C

/*
* Copyright (c) 2000-2002,2005 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_types.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
STATIC int xfs_trans_unlock_chunk(xfs_log_item_chunk_t *,
int, int, xfs_lsn_t);
/*
* This is called to add the given log item to the transaction's
* list of log items. It must find a free log item descriptor
* or allocate a new one and add the item to that descriptor.
* The function returns a pointer to item descriptor used to point
* to the new item. The log item will now point to its new descriptor
* with its li_desc field.
*/
xfs_log_item_desc_t *
xfs_trans_add_item(xfs_trans_t *tp, xfs_log_item_t *lip)
{
xfs_log_item_desc_t *lidp;
xfs_log_item_chunk_t *licp;
int i=0;
/*
* If there are no free descriptors, allocate a new chunk
* of them and put it at the front of the chunk list.
*/
if (tp->t_items_free == 0) {
licp = (xfs_log_item_chunk_t*)
kmem_alloc(sizeof(xfs_log_item_chunk_t), KM_SLEEP);
ASSERT(licp != NULL);
/*
* Initialize the chunk, and then
* claim the first slot in the newly allocated chunk.
*/
XFS_LIC_INIT(licp);
XFS_LIC_CLAIM(licp, 0);
licp->lic_unused = 1;
XFS_LIC_INIT_SLOT(licp, 0);
lidp = XFS_LIC_SLOT(licp, 0);
/*
* Link in the new chunk and update the free count.
*/
licp->lic_next = tp->t_items.lic_next;
tp->t_items.lic_next = licp;
tp->t_items_free = XFS_LIC_NUM_SLOTS - 1;
/*
* Initialize the descriptor and the generic portion
* of the log item.
*
* Point the new slot at this item and return it.
* Also point the log item at its currently active
* descriptor and set the item's mount pointer.
*/
lidp->lid_item = lip;
lidp->lid_flags = 0;
lidp->lid_size = 0;
lip->li_desc = lidp;
lip->li_mountp = tp->t_mountp;
return lidp;
}
/*
* Find the free descriptor. It is somewhere in the chunklist
* of descriptors.
*/
licp = &tp->t_items;
while (licp != NULL) {
if (XFS_LIC_VACANCY(licp)) {
if (licp->lic_unused <= XFS_LIC_MAX_SLOT) {
i = licp->lic_unused;
ASSERT(XFS_LIC_ISFREE(licp, i));
break;
}
for (i = 0; i <= XFS_LIC_MAX_SLOT; i++) {
if (XFS_LIC_ISFREE(licp, i))
break;
}
ASSERT(i <= XFS_LIC_MAX_SLOT);
break;
}
licp = licp->lic_next;
}
ASSERT(licp != NULL);
/*
* If we find a free descriptor, claim it,
* initialize it, and return it.
*/
XFS_LIC_CLAIM(licp, i);
if (licp->lic_unused <= i) {
licp->lic_unused = i + 1;
XFS_LIC_INIT_SLOT(licp, i);
}
lidp = XFS_LIC_SLOT(licp, i);
tp->t_items_free--;
lidp->lid_item = lip;
lidp->lid_flags = 0;
lidp->lid_size = 0;
lip->li_desc = lidp;
lip->li_mountp = tp->t_mountp;
return lidp;
}
/*
* Free the given descriptor.
*
* This requires setting the bit in the chunk's free mask corresponding
* to the given slot.
*/
void
xfs_trans_free_item(xfs_trans_t *tp, xfs_log_item_desc_t *lidp)
{
uint slot;
xfs_log_item_chunk_t *licp;
xfs_log_item_chunk_t **licpp;
slot = XFS_LIC_DESC_TO_SLOT(lidp);
licp = XFS_LIC_DESC_TO_CHUNK(lidp);
XFS_LIC_RELSE(licp, slot);
lidp->lid_item->li_desc = NULL;
tp->t_items_free++;
/*
* If there are no more used items in the chunk and this is not
* the chunk embedded in the transaction structure, then free
* the chunk. First pull it from the chunk list and then
* free it back to the heap. We didn't bother with a doubly
* linked list here because the lists should be very short
* and this is not a performance path. It's better to save
* the memory of the extra pointer.
*
* Also decrement the transaction structure's count of free items
* by the number in a chunk since we are freeing an empty chunk.
*/
if (XFS_LIC_ARE_ALL_FREE(licp) && (licp != &(tp->t_items))) {
licpp = &(tp->t_items.lic_next);
while (*licpp != licp) {
ASSERT(*licpp != NULL);
licpp = &((*licpp)->lic_next);
}
*licpp = licp->lic_next;
kmem_free(licp, sizeof(xfs_log_item_chunk_t));
tp->t_items_free -= XFS_LIC_NUM_SLOTS;
}
}
/*
* This is called to find the descriptor corresponding to the given
* log item. It returns a pointer to the descriptor.
* The log item MUST have a corresponding descriptor in the given
* transaction. This routine does not return NULL, it panics.
*
* The descriptor pointer is kept in the log item's li_desc field.
* Just return it.
*/
/*ARGSUSED*/
xfs_log_item_desc_t *
xfs_trans_find_item(xfs_trans_t *tp, xfs_log_item_t *lip)
{
ASSERT(lip->li_desc != NULL);
return lip->li_desc;
}
/*
* Return a pointer to the first descriptor in the chunk list.
* This does not return NULL if there are none, it panics.
*
* The first descriptor must be in either the first or second chunk.
* This is because the only chunk allowed to be empty is the first.
* All others are freed when they become empty.
*
* At some point this and xfs_trans_next_item() should be optimized
* to quickly look at the mask to determine if there is anything to
* look at.
*/
xfs_log_item_desc_t *
xfs_trans_first_item(xfs_trans_t *tp)
{
xfs_log_item_chunk_t *licp;
int i;
licp = &tp->t_items;
/*
* If it's not in the first chunk, skip to the second.
*/
if (XFS_LIC_ARE_ALL_FREE(licp)) {
licp = licp->lic_next;
}
/*
* Return the first non-free descriptor in the chunk.
*/
ASSERT(!XFS_LIC_ARE_ALL_FREE(licp));
for (i = 0; i < licp->lic_unused; i++) {
if (XFS_LIC_ISFREE(licp, i)) {
continue;
}
return XFS_LIC_SLOT(licp, i);
}
cmn_err(CE_WARN, "xfs_trans_first_item() -- no first item");
return NULL;
}
/*
* Given a descriptor, return the next descriptor in the chunk list.
* This returns NULL if there are no more used descriptors in the list.
*
* We do this by first locating the chunk in which the descriptor resides,
* and then scanning forward in the chunk and the list for the next
* used descriptor.
*/
/*ARGSUSED*/
xfs_log_item_desc_t *
xfs_trans_next_item(xfs_trans_t *tp, xfs_log_item_desc_t *lidp)
{
xfs_log_item_chunk_t *licp;
int i;
licp = XFS_LIC_DESC_TO_CHUNK(lidp);
/*
* First search the rest of the chunk. The for loop keeps us
* from referencing things beyond the end of the chunk.
*/
for (i = (int)XFS_LIC_DESC_TO_SLOT(lidp) + 1; i < licp->lic_unused; i++) {
if (XFS_LIC_ISFREE(licp, i)) {
continue;
}
return XFS_LIC_SLOT(licp, i);
}
/*
* Now search the next chunk. It must be there, because the
* next chunk would have been freed if it were empty.
* If there is no next chunk, return NULL.
*/
if (licp->lic_next == NULL) {
return NULL;
}
licp = licp->lic_next;
ASSERT(!XFS_LIC_ARE_ALL_FREE(licp));
for (i = 0; i < licp->lic_unused; i++) {
if (XFS_LIC_ISFREE(licp, i)) {
continue;
}
return XFS_LIC_SLOT(licp, i);
}
ASSERT(0);
/* NOTREACHED */
return NULL; /* keep gcc quite */
}
/*
* This is called to unlock all of the items of a transaction and to free
* all the descriptors of that transaction.
*
* It walks the list of descriptors and unlocks each item. It frees
* each chunk except that embedded in the transaction as it goes along.
*/
void
xfs_trans_free_items(
xfs_trans_t *tp,
int flags)
{
xfs_log_item_chunk_t *licp;
xfs_log_item_chunk_t *next_licp;
int abort;
abort = flags & XFS_TRANS_ABORT;
licp = &tp->t_items;
/*
* Special case the embedded chunk so we don't free it below.
*/
if (!XFS_LIC_ARE_ALL_FREE(licp)) {
(void) xfs_trans_unlock_chunk(licp, 1, abort, NULLCOMMITLSN);
XFS_LIC_ALL_FREE(licp);
licp->lic_unused = 0;
}
licp = licp->lic_next;
/*
* Unlock each item in each chunk and free the chunks.
*/
while (licp != NULL) {
ASSERT(!XFS_LIC_ARE_ALL_FREE(licp));
(void) xfs_trans_unlock_chunk(licp, 1, abort, NULLCOMMITLSN);
next_licp = licp->lic_next;
kmem_free(licp, sizeof(xfs_log_item_chunk_t));
licp = next_licp;
}
/*
* Reset the transaction structure's free item count.
*/
tp->t_items_free = XFS_LIC_NUM_SLOTS;
tp->t_items.lic_next = NULL;
}
/*
* This is called to unlock the items associated with a transaction.
* Items which were not logged should be freed.
* Those which were logged must still be tracked so they can be unpinned
* when the transaction commits.
*/
void
xfs_trans_unlock_items(xfs_trans_t *tp, xfs_lsn_t commit_lsn)
{
xfs_log_item_chunk_t *licp;
xfs_log_item_chunk_t *next_licp;
xfs_log_item_chunk_t **licpp;
int freed;
freed = 0;
licp = &tp->t_items;
/*
* Special case the embedded chunk so we don't free.
*/
if (!XFS_LIC_ARE_ALL_FREE(licp)) {
freed = xfs_trans_unlock_chunk(licp, 0, 0, commit_lsn);
}
licpp = &(tp->t_items.lic_next);
licp = licp->lic_next;
/*
* Unlock each item in each chunk, free non-dirty descriptors,
* and free empty chunks.
*/
while (licp != NULL) {
ASSERT(!XFS_LIC_ARE_ALL_FREE(licp));
freed += xfs_trans_unlock_chunk(licp, 0, 0, commit_lsn);
next_licp = licp->lic_next;
if (XFS_LIC_ARE_ALL_FREE(licp)) {
*licpp = next_licp;
kmem_free(licp, sizeof(xfs_log_item_chunk_t));
freed -= XFS_LIC_NUM_SLOTS;
} else {
licpp = &(licp->lic_next);
}
ASSERT(*licpp == next_licp);
licp = next_licp;
}
/*
* Fix the free descriptor count in the transaction.
*/
tp->t_items_free += freed;
}
/*
* Unlock each item pointed to by a descriptor in the given chunk.
* Stamp the commit lsn into each item if necessary.
* Free descriptors pointing to items which are not dirty if freeing_chunk
* is zero. If freeing_chunk is non-zero, then we need to unlock all
* items in the chunk.
*
* Return the number of descriptors freed.
*/
STATIC int
xfs_trans_unlock_chunk(
xfs_log_item_chunk_t *licp,
int freeing_chunk,
int abort,
xfs_lsn_t commit_lsn)
{
xfs_log_item_desc_t *lidp;
xfs_log_item_t *lip;
int i;
int freed;
freed = 0;
lidp = licp->lic_descs;
for (i = 0; i < licp->lic_unused; i++, lidp++) {
if (XFS_LIC_ISFREE(licp, i)) {
continue;
}
lip = lidp->lid_item;
lip->li_desc = NULL;
if (commit_lsn != NULLCOMMITLSN)
IOP_COMMITTING(lip, commit_lsn);
if (abort)
lip->li_flags |= XFS_LI_ABORTED;
IOP_UNLOCK(lip);
/*
* Free the descriptor if the item is not dirty
* within this transaction and the caller is not
* going to just free the entire thing regardless.
*/
if (!(freeing_chunk) &&
(!(lidp->lid_flags & XFS_LID_DIRTY) || abort)) {
XFS_LIC_RELSE(licp, i);
freed++;
}
}
return freed;
}
/*
* This is called to add the given busy item to the transaction's
* list of busy items. It must find a free busy item descriptor
* or allocate a new one and add the item to that descriptor.
* The function returns a pointer to busy descriptor used to point
* to the new busy entry. The log busy entry will now point to its new
* descriptor with its ???? field.
*/
xfs_log_busy_slot_t *
xfs_trans_add_busy(xfs_trans_t *tp, xfs_agnumber_t ag, xfs_extlen_t idx)
{
xfs_log_busy_chunk_t *lbcp;
xfs_log_busy_slot_t *lbsp;
int i=0;
/*
* If there are no free descriptors, allocate a new chunk
* of them and put it at the front of the chunk list.
*/
if (tp->t_busy_free == 0) {
lbcp = (xfs_log_busy_chunk_t*)
kmem_alloc(sizeof(xfs_log_busy_chunk_t), KM_SLEEP);
ASSERT(lbcp != NULL);
/*
* Initialize the chunk, and then
* claim the first slot in the newly allocated chunk.
*/
XFS_LBC_INIT(lbcp);
XFS_LBC_CLAIM(lbcp, 0);
lbcp->lbc_unused = 1;
lbsp = XFS_LBC_SLOT(lbcp, 0);
/*
* Link in the new chunk and update the free count.
*/
lbcp->lbc_next = tp->t_busy.lbc_next;
tp->t_busy.lbc_next = lbcp;
tp->t_busy_free = XFS_LIC_NUM_SLOTS - 1;
/*
* Initialize the descriptor and the generic portion
* of the log item.
*
* Point the new slot at this item and return it.
* Also point the log item at its currently active
* descriptor and set the item's mount pointer.
*/
lbsp->lbc_ag = ag;
lbsp->lbc_idx = idx;
return lbsp;
}
/*
* Find the free descriptor. It is somewhere in the chunklist
* of descriptors.
*/
lbcp = &tp->t_busy;
while (lbcp != NULL) {
if (XFS_LBC_VACANCY(lbcp)) {
if (lbcp->lbc_unused <= XFS_LBC_MAX_SLOT) {
i = lbcp->lbc_unused;
break;
} else {
/* out-of-order vacancy */
printk("OOO vacancy lbcp 0x%p\n", lbcp);
ASSERT(0);
}
}
lbcp = lbcp->lbc_next;
}
ASSERT(lbcp != NULL);
/*
* If we find a free descriptor, claim it,
* initialize it, and return it.
*/
XFS_LBC_CLAIM(lbcp, i);
if (lbcp->lbc_unused <= i) {
lbcp->lbc_unused = i + 1;
}
lbsp = XFS_LBC_SLOT(lbcp, i);
tp->t_busy_free--;
lbsp->lbc_ag = ag;
lbsp->lbc_idx = idx;
return lbsp;
}
/*
* xfs_trans_free_busy
* Free all of the busy lists from a transaction
*/
void
xfs_trans_free_busy(xfs_trans_t *tp)
{
xfs_log_busy_chunk_t *lbcp;
xfs_log_busy_chunk_t *lbcq;
lbcp = tp->t_busy.lbc_next;
while (lbcp != NULL) {
lbcq = lbcp->lbc_next;
kmem_free(lbcp, sizeof(xfs_log_busy_chunk_t));
lbcp = lbcq;
}
XFS_LBC_INIT(&tp->t_busy);
tp->t_busy.lbc_unused = 0;
}