#include "xfs_trace.h"
static kmem_zone_t *xfs_buf_zone;
-STATIC int xfsbufd(void *);
static struct workqueue_struct *xfslogd_workqueue;
xfs_buf_stale(
struct xfs_buf *bp)
{
+ ASSERT(xfs_buf_islocked(bp));
+
bp->b_flags |= XBF_STALE;
- xfs_buf_delwri_dequeue(bp);
+
+ /*
+ * Clear the delwri status so that a delwri queue walker will not
+ * flush this buffer to disk now that it is stale. The delwri queue has
+ * a reference to the buffer, so this is safe to do.
+ */
+ bp->b_flags &= ~_XBF_DELWRI_Q;
+
atomic_set(&(bp)->b_lru_ref, 0);
if (!list_empty(&bp->b_lru)) {
struct xfs_buftarg *btp = bp->b_target;
struct xfs_buf *
xfs_buf_alloc(
struct xfs_buftarg *target,
- xfs_off_t range_base,
- size_t range_length,
+ xfs_daddr_t blkno,
+ size_t numblks,
xfs_buf_flags_t flags)
{
struct xfs_buf *bp;
- bp = kmem_zone_alloc(xfs_buf_zone, xb_to_km(flags));
+ bp = kmem_zone_zalloc(xfs_buf_zone, xb_to_km(flags));
if (unlikely(!bp))
return NULL;
/*
* We don't want certain flags to appear in b_flags.
*/
- flags &= ~(XBF_LOCK|XBF_MAPPED|XBF_DONT_BLOCK|XBF_READ_AHEAD);
+ flags &= ~(XBF_MAPPED|XBF_DONT_BLOCK|XBF_READ_AHEAD);
- memset(bp, 0, sizeof(xfs_buf_t));
atomic_set(&bp->b_hold, 1);
atomic_set(&bp->b_lru_ref, 1);
init_completion(&bp->b_iowait);
sema_init(&bp->b_sema, 0); /* held, no waiters */
XB_SET_OWNER(bp);
bp->b_target = target;
- bp->b_file_offset = range_base;
+
/*
- * Set buffer_length and count_desired to the same value initially.
- * I/O routines should use count_desired, which will be the same in
+ * Set length and io_length to the same value initially.
+ * I/O routines should use io_length, which will be the same in
* most cases but may be reset (e.g. XFS recovery).
*/
- bp->b_buffer_length = bp->b_count_desired = range_length;
+ bp->b_length = numblks;
+ bp->b_io_length = numblks;
bp->b_flags = flags;
+
+ /*
+ * We do not set the block number here in the buffer because we have not
+ * finished initialising the buffer. We insert the buffer into the cache
+ * in this state, so this ensures that we are unable to do IO on a
+ * buffer that hasn't been fully initialised.
+ */
bp->b_bn = XFS_BUF_DADDR_NULL;
atomic_set(&bp->b_pin_count, 0);
init_waitqueue_head(&bp->b_waiters);
{
/* Make sure that we have a page list */
if (bp->b_pages == NULL) {
- bp->b_offset = xfs_buf_poff(bp->b_file_offset);
bp->b_page_count = page_count;
if (page_count <= XB_PAGES) {
bp->b_pages = bp->b_page_array;
xfs_buf_t *bp,
uint flags)
{
- size_t size = bp->b_count_desired;
+ size_t size;
size_t nbytes, offset;
gfp_t gfp_mask = xb_to_gfp(flags);
unsigned short page_count, i;
- xfs_off_t end;
+ xfs_off_t start, end;
int error;
/*
* the memory from the heap - there's no need for the complexity of
* page arrays to keep allocation down to order 0.
*/
- if (bp->b_buffer_length < PAGE_SIZE) {
- bp->b_addr = kmem_alloc(bp->b_buffer_length, xb_to_km(flags));
+ size = BBTOB(bp->b_length);
+ if (size < PAGE_SIZE) {
+ bp->b_addr = kmem_alloc(size, xb_to_km(flags));
if (!bp->b_addr) {
/* low memory - use alloc_page loop instead */
goto use_alloc_page;
}
- if (((unsigned long)(bp->b_addr + bp->b_buffer_length - 1) &
- PAGE_MASK) !=
+ if (((unsigned long)(bp->b_addr + size - 1) & PAGE_MASK) !=
((unsigned long)bp->b_addr & PAGE_MASK)) {
/* b_addr spans two pages - use alloc_page instead */
kmem_free(bp->b_addr);
}
use_alloc_page:
- end = bp->b_file_offset + bp->b_buffer_length;
- page_count = xfs_buf_btoc(end) - xfs_buf_btoct(bp->b_file_offset);
+ start = BBTOB(bp->b_bn) >> PAGE_SHIFT;
+ end = (BBTOB(bp->b_bn + bp->b_length) + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ page_count = end - start;
error = _xfs_buf_get_pages(bp, page_count, flags);
if (unlikely(error))
return error;
*/
xfs_buf_t *
_xfs_buf_find(
- xfs_buftarg_t *btp, /* block device target */
- xfs_off_t ioff, /* starting offset of range */
- size_t isize, /* length of range */
+ struct xfs_buftarg *btp,
+ xfs_daddr_t blkno,
+ size_t numblks,
xfs_buf_flags_t flags,
xfs_buf_t *new_bp)
{
- xfs_off_t range_base;
- size_t range_length;
+ size_t numbytes;
struct xfs_perag *pag;
struct rb_node **rbp;
struct rb_node *parent;
xfs_buf_t *bp;
- range_base = (ioff << BBSHIFT);
- range_length = (isize << BBSHIFT);
+ numbytes = BBTOB(numblks);
/* Check for IOs smaller than the sector size / not sector aligned */
- ASSERT(!(range_length < (1 << btp->bt_sshift)));
- ASSERT(!(range_base & (xfs_off_t)btp->bt_smask));
+ ASSERT(!(numbytes < (1 << btp->bt_sshift)));
+ ASSERT(!(BBTOB(blkno) & (xfs_off_t)btp->bt_smask));
/* get tree root */
pag = xfs_perag_get(btp->bt_mount,
- xfs_daddr_to_agno(btp->bt_mount, ioff));
+ xfs_daddr_to_agno(btp->bt_mount, blkno));
/* walk tree */
spin_lock(&pag->pag_buf_lock);
parent = *rbp;
bp = rb_entry(parent, struct xfs_buf, b_rbnode);
- if (range_base < bp->b_file_offset)
+ if (blkno < bp->b_bn)
rbp = &(*rbp)->rb_left;
- else if (range_base > bp->b_file_offset)
+ else if (blkno > bp->b_bn)
rbp = &(*rbp)->rb_right;
else {
/*
- * found a block offset match. If the range doesn't
+ * found a block number match. If the range doesn't
* match, the only way this is allowed is if the buffer
* in the cache is stale and the transaction that made
* it stale has not yet committed. i.e. we are
* reallocating a busy extent. Skip this buffer and
* continue searching to the right for an exact match.
*/
- if (bp->b_buffer_length != range_length) {
+ if (bp->b_length != numblks) {
ASSERT(bp->b_flags & XBF_STALE);
rbp = &(*rbp)->rb_right;
continue;
*/
struct xfs_buf *
xfs_buf_get(
- xfs_buftarg_t *target,/* target for buffer */
- xfs_off_t ioff, /* starting offset of range */
- size_t isize, /* length of range */
+ xfs_buftarg_t *target,
+ xfs_daddr_t blkno,
+ size_t numblks,
xfs_buf_flags_t flags)
{
struct xfs_buf *bp;
struct xfs_buf *new_bp;
int error = 0;
- bp = _xfs_buf_find(target, ioff, isize, flags, NULL);
+ bp = _xfs_buf_find(target, blkno, numblks, flags, NULL);
if (likely(bp))
goto found;
- new_bp = xfs_buf_alloc(target, ioff << BBSHIFT, isize << BBSHIFT,
- flags);
+ new_bp = xfs_buf_alloc(target, blkno, numblks, flags);
if (unlikely(!new_bp))
return NULL;
- bp = _xfs_buf_find(target, ioff, isize, flags, new_bp);
- if (!bp) {
+ error = xfs_buf_allocate_memory(new_bp, flags);
+ if (error) {
kmem_zone_free(xfs_buf_zone, new_bp);
return NULL;
}
- if (bp == new_bp) {
- error = xfs_buf_allocate_memory(bp, flags);
- if (error)
- goto no_buffer;
- } else
- kmem_zone_free(xfs_buf_zone, new_bp);
+ bp = _xfs_buf_find(target, blkno, numblks, flags, new_bp);
+ if (!bp) {
+ xfs_buf_free(new_bp);
+ return NULL;
+ }
+
+ if (bp != new_bp)
+ xfs_buf_free(new_bp);
/*
* Now we have a workable buffer, fill in the block number so
* that we can do IO on it.
*/
- bp->b_bn = ioff;
- bp->b_count_desired = bp->b_buffer_length;
+ bp->b_bn = blkno;
+ bp->b_io_length = bp->b_length;
found:
if (!(bp->b_flags & XBF_MAPPED)) {
if (unlikely(error)) {
xfs_warn(target->bt_mount,
"%s: failed to map pages\n", __func__);
- goto no_buffer;
+ xfs_buf_relse(bp);
+ return NULL;
}
}
XFS_STATS_INC(xb_get);
trace_xfs_buf_get(bp, flags, _RET_IP_);
return bp;
-
-no_buffer:
- if (flags & (XBF_LOCK | XBF_TRYLOCK))
- xfs_buf_unlock(bp);
- xfs_buf_rele(bp);
- return NULL;
}
STATIC int
xfs_buf_t *bp,
xfs_buf_flags_t flags)
{
- int status;
-
- ASSERT(!(flags & (XBF_DELWRI|XBF_WRITE)));
+ ASSERT(!(flags & XBF_WRITE));
ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL);
- bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_DELWRI | XBF_READ_AHEAD);
+ bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_READ_AHEAD);
bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | XBF_READ_AHEAD);
- status = xfs_buf_iorequest(bp);
- if (status || bp->b_error || (flags & XBF_ASYNC))
- return status;
+ xfs_buf_iorequest(bp);
+ if (flags & XBF_ASYNC)
+ return 0;
return xfs_buf_iowait(bp);
}
xfs_buf_t *
xfs_buf_read(
xfs_buftarg_t *target,
- xfs_off_t ioff,
- size_t isize,
+ xfs_daddr_t blkno,
+ size_t numblks,
xfs_buf_flags_t flags)
{
xfs_buf_t *bp;
flags |= XBF_READ;
- bp = xfs_buf_get(target, ioff, isize, flags);
+ bp = xfs_buf_get(target, blkno, numblks, flags);
if (bp) {
trace_xfs_buf_read(bp, flags, _RET_IP_);
* Read ahead call which is already satisfied,
* drop the buffer
*/
- goto no_buffer;
+ xfs_buf_relse(bp);
+ return NULL;
} else {
/* We do not want read in the flags */
bp->b_flags &= ~XBF_READ;
}
return bp;
-
- no_buffer:
- if (flags & (XBF_LOCK | XBF_TRYLOCK))
- xfs_buf_unlock(bp);
- xfs_buf_rele(bp);
- return NULL;
}
/*
void
xfs_buf_readahead(
xfs_buftarg_t *target,
- xfs_off_t ioff,
- size_t isize)
+ xfs_daddr_t blkno,
+ size_t numblks)
{
if (bdi_read_congested(target->bt_bdi))
return;
- xfs_buf_read(target, ioff, isize,
+ xfs_buf_read(target, blkno, numblks,
XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD|XBF_DONT_BLOCK);
}
*/
struct xfs_buf *
xfs_buf_read_uncached(
- struct xfs_mount *mp,
struct xfs_buftarg *target,
xfs_daddr_t daddr,
- size_t length,
+ size_t numblks,
int flags)
{
xfs_buf_t *bp;
int error;
- bp = xfs_buf_get_uncached(target, length, flags);
+ bp = xfs_buf_get_uncached(target, numblks, flags);
if (!bp)
return NULL;
XFS_BUF_SET_ADDR(bp, daddr);
XFS_BUF_READ(bp);
- xfsbdstrat(mp, bp);
+ xfsbdstrat(target->bt_mount, bp);
error = xfs_buf_iowait(bp);
- if (error || bp->b_error) {
+ if (error) {
xfs_buf_relse(bp);
return NULL;
}
void
xfs_buf_set_empty(
struct xfs_buf *bp,
- size_t len)
+ size_t numblks)
{
if (bp->b_pages)
_xfs_buf_free_pages(bp);
bp->b_pages = NULL;
bp->b_page_count = 0;
bp->b_addr = NULL;
- bp->b_file_offset = 0;
- bp->b_buffer_length = bp->b_count_desired = len;
+ bp->b_length = numblks;
+ bp->b_io_length = numblks;
bp->b_bn = XFS_BUF_DADDR_NULL;
bp->b_flags &= ~XBF_MAPPED;
}
pageaddr += PAGE_SIZE;
}
- bp->b_count_desired = len;
- bp->b_buffer_length = buflen;
+ bp->b_io_length = BTOBB(len);
+ bp->b_length = BTOBB(buflen);
bp->b_flags |= XBF_MAPPED;
return 0;
xfs_buf_t *
xfs_buf_get_uncached(
struct xfs_buftarg *target,
- size_t len,
+ size_t numblks,
int flags)
{
- unsigned long page_count = PAGE_ALIGN(len) >> PAGE_SHIFT;
+ unsigned long page_count;
int error, i;
xfs_buf_t *bp;
- bp = xfs_buf_alloc(target, 0, len, 0);
+ bp = xfs_buf_alloc(target, 0, numblks, 0);
if (unlikely(bp == NULL))
goto fail;
+ page_count = PAGE_ALIGN(numblks << BBSHIFT) >> PAGE_SHIFT;
error = _xfs_buf_get_pages(bp, page_count, 0);
if (error)
goto fail_free_buf;
spin_unlock(&pag->pag_buf_lock);
} else {
xfs_buf_lru_del(bp);
- ASSERT(!(bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q)));
+ ASSERT(!(bp->b_flags & _XBF_DELWRI_Q));
rb_erase(&bp->b_rbnode, &pag->pag_buf_tree);
spin_unlock(&pag->pag_buf_lock);
xfs_perag_put(pag);
trace_xfs_buf_lock_done(bp, _RET_IP_);
}
-/*
- * Releases the lock on the buffer object.
- * If the buffer is marked delwri but is not queued, do so before we
- * unlock the buffer as we need to set flags correctly. We also need to
- * take a reference for the delwri queue because the unlocker is going to
- * drop their's and they don't know we just queued it.
- */
void
xfs_buf_unlock(
struct xfs_buf *bp)
const char *func)
{
xfs_alert(bp->b_target->bt_mount,
-"metadata I/O error: block 0x%llx (\"%s\") error %d buf count %zd",
- (__uint64_t)XFS_BUF_ADDR(bp), func,
- bp->b_error, XFS_BUF_COUNT(bp));
+"metadata I/O error: block 0x%llx (\"%s\") error %d numblks %d",
+ (__uint64_t)XFS_BUF_ADDR(bp), func, bp->b_error, bp->b_length);
}
int
{
int error;
+ ASSERT(xfs_buf_islocked(bp));
+
bp->b_flags |= XBF_WRITE;
- bp->b_flags &= ~(XBF_ASYNC | XBF_READ);
+ bp->b_flags &= ~(XBF_ASYNC | XBF_READ | _XBF_DELWRI_Q);
- xfs_buf_delwri_dequeue(bp);
xfs_bdstrat_cb(bp);
error = xfs_buf_iowait(bp);
int rw, map_i, total_nr_pages, nr_pages;
struct bio *bio;
int offset = bp->b_offset;
- int size = bp->b_count_desired;
+ int size = BBTOB(bp->b_io_length);
sector_t sector = bp->b_bn;
total_nr_pages = bp->b_page_count;
break;
offset = 0;
- sector += nbytes >> BBSHIFT;
+ sector += BTOBB(nbytes);
size -= nbytes;
total_nr_pages--;
}
}
}
-int
+void
xfs_buf_iorequest(
xfs_buf_t *bp)
{
trace_xfs_buf_iorequest(bp, _RET_IP_);
- ASSERT(!(bp->b_flags & XBF_DELWRI));
+ ASSERT(!(bp->b_flags & _XBF_DELWRI_Q));
if (bp->b_flags & XBF_WRITE)
xfs_buf_wait_unpin(bp);
_xfs_buf_ioend(bp, 0);
xfs_buf_rele(bp);
- return 0;
}
/*
- * Waits for I/O to complete on the buffer supplied.
- * It returns immediately if no I/O is pending.
- * It returns the I/O error code, if any, or 0 if there was no error.
+ * Waits for I/O to complete on the buffer supplied. It returns immediately if
+ * no I/O is pending or there is already a pending error on the buffer. It
+ * returns the I/O error code, if any, or 0 if there was no error.
*/
int
xfs_buf_iowait(
{
trace_xfs_buf_iowait(bp, _RET_IP_);
- wait_for_completion(&bp->b_iowait);
+ if (!bp->b_error)
+ wait_for_completion(&bp->b_iowait);
trace_xfs_buf_iowait_done(bp, _RET_IP_);
return bp->b_error;
void *data, /* data address */
xfs_buf_rw_t mode) /* read/write/zero flag */
{
- size_t bend, cpoff, csize;
- struct page *page;
+ size_t bend;
bend = boff + bsize;
while (boff < bend) {
- page = bp->b_pages[xfs_buf_btoct(boff + bp->b_offset)];
- cpoff = xfs_buf_poff(boff + bp->b_offset);
- csize = min_t(size_t,
- PAGE_SIZE-cpoff, bp->b_count_desired-boff);
+ struct page *page;
+ int page_index, page_offset, csize;
+
+ page_index = (boff + bp->b_offset) >> PAGE_SHIFT;
+ page_offset = (boff + bp->b_offset) & ~PAGE_MASK;
+ page = bp->b_pages[page_index];
+ csize = min_t(size_t, PAGE_SIZE - page_offset,
+ BBTOB(bp->b_io_length) - boff);
- ASSERT(((csize + cpoff) <= PAGE_SIZE));
+ ASSERT((csize + page_offset) <= PAGE_SIZE);
switch (mode) {
case XBRW_ZERO:
- memset(page_address(page) + cpoff, 0, csize);
+ memset(page_address(page) + page_offset, 0, csize);
break;
case XBRW_READ:
- memcpy(data, page_address(page) + cpoff, csize);
+ memcpy(data, page_address(page) + page_offset, csize);
break;
case XBRW_WRITE:
- memcpy(page_address(page) + cpoff, data, csize);
+ memcpy(page_address(page) + page_offset, data, csize);
}
boff += csize;
{
unregister_shrinker(&btp->bt_shrinker);
- xfs_flush_buftarg(btp, 1);
if (mp->m_flags & XFS_MOUNT_BARRIER)
xfs_blkdev_issue_flush(btp);
- kthread_stop(btp->bt_task);
kmem_free(btp);
}
return xfs_setsize_buftarg_flags(btp, blocksize, sectorsize, 1);
}
-STATIC int
-xfs_alloc_delwri_queue(
- xfs_buftarg_t *btp,
- const char *fsname)
-{
- INIT_LIST_HEAD(&btp->bt_delwri_queue);
- spin_lock_init(&btp->bt_delwri_lock);
- btp->bt_flags = 0;
- btp->bt_task = kthread_run(xfsbufd, btp, "xfsbufd/%s", fsname);
- if (IS_ERR(btp->bt_task))
- return PTR_ERR(btp->bt_task);
- return 0;
-}
-
xfs_buftarg_t *
xfs_alloc_buftarg(
struct xfs_mount *mp,
spin_lock_init(&btp->bt_lru_lock);
if (xfs_setsize_buftarg_early(btp, bdev))
goto error;
- if (xfs_alloc_delwri_queue(btp, fsname))
- goto error;
btp->bt_shrinker.shrink = xfs_buftarg_shrink;
btp->bt_shrinker.seeks = DEFAULT_SEEKS;
register_shrinker(&btp->bt_shrinker);
return NULL;
}
-
/*
- * Delayed write buffer handling
+ * Add a buffer to the delayed write list.
+ *
+ * This queues a buffer for writeout if it hasn't already been. Note that
+ * neither this routine nor the buffer list submission functions perform
+ * any internal synchronization. It is expected that the lists are thread-local
+ * to the callers.
+ *
+ * Returns true if we queued up the buffer, or false if it already had
+ * been on the buffer list.
*/
-void
+bool
xfs_buf_delwri_queue(
- xfs_buf_t *bp)
+ struct xfs_buf *bp,
+ struct list_head *list)
{
- struct xfs_buftarg *btp = bp->b_target;
-
- trace_xfs_buf_delwri_queue(bp, _RET_IP_);
-
+ ASSERT(xfs_buf_islocked(bp));
ASSERT(!(bp->b_flags & XBF_READ));
- spin_lock(&btp->bt_delwri_lock);
- if (!list_empty(&bp->b_list)) {
- /* if already in the queue, move it to the tail */
- ASSERT(bp->b_flags & _XBF_DELWRI_Q);
- list_move_tail(&bp->b_list, &btp->bt_delwri_queue);
- } else {
- /* start xfsbufd as it is about to have something to do */
- if (list_empty(&btp->bt_delwri_queue))
- wake_up_process(bp->b_target->bt_task);
-
- atomic_inc(&bp->b_hold);
- bp->b_flags |= XBF_DELWRI | _XBF_DELWRI_Q | XBF_ASYNC;
- list_add_tail(&bp->b_list, &btp->bt_delwri_queue);
- }
- bp->b_queuetime = jiffies;
- spin_unlock(&btp->bt_delwri_lock);
-}
-
-void
-xfs_buf_delwri_dequeue(
- xfs_buf_t *bp)
-{
- int dequeued = 0;
-
- spin_lock(&bp->b_target->bt_delwri_lock);
- if ((bp->b_flags & XBF_DELWRI) && !list_empty(&bp->b_list)) {
- ASSERT(bp->b_flags & _XBF_DELWRI_Q);
- list_del_init(&bp->b_list);
- dequeued = 1;
+ /*
+ * If the buffer is already marked delwri it already is queued up
+ * by someone else for imediate writeout. Just ignore it in that
+ * case.
+ */
+ if (bp->b_flags & _XBF_DELWRI_Q) {
+ trace_xfs_buf_delwri_queued(bp, _RET_IP_);
+ return false;
}
- bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q);
- spin_unlock(&bp->b_target->bt_delwri_lock);
-
- if (dequeued)
- xfs_buf_rele(bp);
-
- trace_xfs_buf_delwri_dequeue(bp, _RET_IP_);
-}
-
-/*
- * If a delwri buffer needs to be pushed before it has aged out, then promote
- * it to the head of the delwri queue so that it will be flushed on the next
- * xfsbufd run. We do this by resetting the queuetime of the buffer to be older
- * than the age currently needed to flush the buffer. Hence the next time the
- * xfsbufd sees it is guaranteed to be considered old enough to flush.
- */
-void
-xfs_buf_delwri_promote(
- struct xfs_buf *bp)
-{
- struct xfs_buftarg *btp = bp->b_target;
- long age = xfs_buf_age_centisecs * msecs_to_jiffies(10) + 1;
- ASSERT(bp->b_flags & XBF_DELWRI);
- ASSERT(bp->b_flags & _XBF_DELWRI_Q);
+ trace_xfs_buf_delwri_queue(bp, _RET_IP_);
/*
- * Check the buffer age before locking the delayed write queue as we
- * don't need to promote buffers that are already past the flush age.
+ * If a buffer gets written out synchronously or marked stale while it
+ * is on a delwri list we lazily remove it. To do this, the other party
+ * clears the _XBF_DELWRI_Q flag but otherwise leaves the buffer alone.
+ * It remains referenced and on the list. In a rare corner case it
+ * might get readded to a delwri list after the synchronous writeout, in
+ * which case we need just need to re-add the flag here.
*/
- if (bp->b_queuetime < jiffies - age)
- return;
- bp->b_queuetime = jiffies - age;
- spin_lock(&btp->bt_delwri_lock);
- list_move(&bp->b_list, &btp->bt_delwri_queue);
- spin_unlock(&btp->bt_delwri_lock);
-}
-
-/*
- * Move as many buffers as specified to the supplied list
- * idicating if we skipped any buffers to prevent deadlocks.
- */
-STATIC int
-xfs_buf_delwri_split(
- xfs_buftarg_t *target,
- struct list_head *list,
- unsigned long age)
-{
- xfs_buf_t *bp, *n;
- int skipped = 0;
- int force;
-
- force = test_and_clear_bit(XBT_FORCE_FLUSH, &target->bt_flags);
- INIT_LIST_HEAD(list);
- spin_lock(&target->bt_delwri_lock);
- list_for_each_entry_safe(bp, n, &target->bt_delwri_queue, b_list) {
- ASSERT(bp->b_flags & XBF_DELWRI);
-
- if (!xfs_buf_ispinned(bp) && xfs_buf_trylock(bp)) {
- if (!force &&
- time_before(jiffies, bp->b_queuetime + age)) {
- xfs_buf_unlock(bp);
- break;
- }
-
- bp->b_flags &= ~(XBF_DELWRI | _XBF_DELWRI_Q);
- bp->b_flags |= XBF_WRITE;
- list_move_tail(&bp->b_list, list);
- trace_xfs_buf_delwri_split(bp, _RET_IP_);
- } else
- skipped++;
+ bp->b_flags |= _XBF_DELWRI_Q;
+ if (list_empty(&bp->b_list)) {
+ atomic_inc(&bp->b_hold);
+ list_add_tail(&bp->b_list, list);
}
- spin_unlock(&target->bt_delwri_lock);
- return skipped;
+ return true;
}
/*
return 0;
}
-STATIC int
-xfsbufd(
- void *data)
+static int
+__xfs_buf_delwri_submit(
+ struct list_head *buffer_list,
+ struct list_head *io_list,
+ bool wait)
{
- xfs_buftarg_t *target = (xfs_buftarg_t *)data;
-
- current->flags |= PF_MEMALLOC;
-
- set_freezable();
+ struct blk_plug plug;
+ struct xfs_buf *bp, *n;
+ int pinned = 0;
+
+ list_for_each_entry_safe(bp, n, buffer_list, b_list) {
+ if (!wait) {
+ if (xfs_buf_ispinned(bp)) {
+ pinned++;
+ continue;
+ }
+ if (!xfs_buf_trylock(bp))
+ continue;
+ } else {
+ xfs_buf_lock(bp);
+ }
- do {
- long age = xfs_buf_age_centisecs * msecs_to_jiffies(10);
- long tout = xfs_buf_timer_centisecs * msecs_to_jiffies(10);
- struct list_head tmp;
- struct blk_plug plug;
+ /*
+ * Someone else might have written the buffer synchronously or
+ * marked it stale in the meantime. In that case only the
+ * _XBF_DELWRI_Q flag got cleared, and we have to drop the
+ * reference and remove it from the list here.
+ */
+ if (!(bp->b_flags & _XBF_DELWRI_Q)) {
+ list_del_init(&bp->b_list);
+ xfs_buf_relse(bp);
+ continue;
+ }
- if (unlikely(freezing(current)))
- try_to_freeze();
+ list_move_tail(&bp->b_list, io_list);
+ trace_xfs_buf_delwri_split(bp, _RET_IP_);
+ }
- /* sleep for a long time if there is nothing to do. */
- if (list_empty(&target->bt_delwri_queue))
- tout = MAX_SCHEDULE_TIMEOUT;
- schedule_timeout_interruptible(tout);
+ list_sort(NULL, io_list, xfs_buf_cmp);
- xfs_buf_delwri_split(target, &tmp, age);
- list_sort(NULL, &tmp, xfs_buf_cmp);
+ blk_start_plug(&plug);
+ list_for_each_entry_safe(bp, n, io_list, b_list) {
+ bp->b_flags &= ~(_XBF_DELWRI_Q | XBF_ASYNC);
+ bp->b_flags |= XBF_WRITE;
- blk_start_plug(&plug);
- while (!list_empty(&tmp)) {
- struct xfs_buf *bp;
- bp = list_first_entry(&tmp, struct xfs_buf, b_list);
+ if (!wait) {
+ bp->b_flags |= XBF_ASYNC;
list_del_init(&bp->b_list);
- xfs_bdstrat_cb(bp);
}
- blk_finish_plug(&plug);
- } while (!kthread_should_stop());
+ xfs_bdstrat_cb(bp);
+ }
+ blk_finish_plug(&plug);
- return 0;
+ return pinned;
}
/*
- * Go through all incore buffers, and release buffers if they belong to
- * the given device. This is used in filesystem error handling to
- * preserve the consistency of its metadata.
+ * Write out a buffer list asynchronously.
+ *
+ * This will take the @buffer_list, write all non-locked and non-pinned buffers
+ * out and not wait for I/O completion on any of the buffers. This interface
+ * is only safely useable for callers that can track I/O completion by higher
+ * level means, e.g. AIL pushing as the @buffer_list is consumed in this
+ * function.
*/
int
-xfs_flush_buftarg(
- xfs_buftarg_t *target,
- int wait)
+xfs_buf_delwri_submit_nowait(
+ struct list_head *buffer_list)
{
- xfs_buf_t *bp;
- int pincount = 0;
- LIST_HEAD(tmp_list);
- LIST_HEAD(wait_list);
- struct blk_plug plug;
+ LIST_HEAD (io_list);
+ return __xfs_buf_delwri_submit(buffer_list, &io_list, false);
+}
- flush_workqueue(xfslogd_workqueue);
+/*
+ * Write out a buffer list synchronously.
+ *
+ * This will take the @buffer_list, write all buffers out and wait for I/O
+ * completion on all of the buffers. @buffer_list is consumed by the function,
+ * so callers must have some other way of tracking buffers if they require such
+ * functionality.
+ */
+int
+xfs_buf_delwri_submit(
+ struct list_head *buffer_list)
+{
+ LIST_HEAD (io_list);
+ int error = 0, error2;
+ struct xfs_buf *bp;
- set_bit(XBT_FORCE_FLUSH, &target->bt_flags);
- pincount = xfs_buf_delwri_split(target, &tmp_list, 0);
+ __xfs_buf_delwri_submit(buffer_list, &io_list, true);
- /*
- * Dropped the delayed write list lock, now walk the temporary list.
- * All I/O is issued async and then if we need to wait for completion
- * we do that after issuing all the IO.
- */
- list_sort(NULL, &tmp_list, xfs_buf_cmp);
+ /* Wait for IO to complete. */
+ while (!list_empty(&io_list)) {
+ bp = list_first_entry(&io_list, struct xfs_buf, b_list);
- blk_start_plug(&plug);
- while (!list_empty(&tmp_list)) {
- bp = list_first_entry(&tmp_list, struct xfs_buf, b_list);
- ASSERT(target == bp->b_target);
list_del_init(&bp->b_list);
- if (wait) {
- bp->b_flags &= ~XBF_ASYNC;
- list_add(&bp->b_list, &wait_list);
- }
- xfs_bdstrat_cb(bp);
- }
- blk_finish_plug(&plug);
-
- if (wait) {
- /* Wait for IO to complete. */
- while (!list_empty(&wait_list)) {
- bp = list_first_entry(&wait_list, struct xfs_buf, b_list);
-
- list_del_init(&bp->b_list);
- xfs_buf_iowait(bp);
- xfs_buf_relse(bp);
- }
+ error2 = xfs_buf_iowait(bp);
+ xfs_buf_relse(bp);
+ if (!error)
+ error = error2;
}
- return pincount;
+ return error;
}
int __init
projects / firefly-linux-kernel-4.4.55.git / blobdiff