| Message ID | 20170718145415.21230-3-cmaiolino@redhat.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Tue, Jul 18, 2017 at 04:54:15PM +0200, Carlos Maiolino wrote: > When a buffer has been failed during writeback, the inode items into it > are kept flush locked, and are never resubmitted due the flush lock, so, > if any buffer fails to be written, the items in AIL are never written to > disk and never unlocked. > > This causes unmount operation to hang due these items flush locked in AIL, > but this also causes the items in AIL to never be written back, even when > the IO device comes back to normal. > > I've been testing this patch with a DM-thin device, creating a > filesystem larger than the real device. > > When writing enough data to fill the DM-thin device, XFS receives ENOSPC > errors from the device, and keep spinning on xfsaild (when 'retry > forever' configuration is set). > > At this point, the filesystem can not be unmounted because of the flush locked > items in AIL, but worse, the items in AIL are never retried at all > (once xfs_inode_item_push() will skip the items that are flush locked), > even if the underlying DM-thin device is expanded to the proper size. > > This patch fixes both cases, retrying any item that has been failed > previously, using the infra-structure provided by the previous patch. > > Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> > --- This version looks pretty good to me. I've added a few style nits below and I need to run some testing, but otherwise the code looks good: Reviewed-by: Brian Foster <bfoster@redhat.com> > > V2: > - Fix XFS_LI_FAILED flag removal > - Use atomic operations to set and clear XFS_LI_FAILED flag > - Remove check for XBF_WRITE_FAIL in xfs_inode_item_push > - Add more comments to the code > - Add a helper function to resubmit the failed buffers, so this > can be also used in dquot system without duplicating code > > V3: > - kill xfs_imap_to_bp call using a pointer in the log item to > hold the buffer address > - use xa_lock instead of atomic operations to handle log item > flags > - Add a hold to the buffer for each log item failed > - move buffer resubmission up in xfs_inode_item_push() > > V4: > - Remove bflags argument from iop_error callback > - Remove ip argument from xfs_buf_resubmit_failed_buffers > - Use helpers to set/clear XFS_LI_FAILED flag > - remove ->xa_lock from the iop->error callback and move it up > on the stack, so all log items are processed into a single > pair of lock/unlock > > V5: > - fix comments > - move buf_lock from xfs_buf_resubmit_failed_buffers() up to > xfs_inode_item_push, and use trylock instead > - assert xa_lock is held in xfs_set/clear_li_failed helpers > and move such helpers into xfs_trans_priv.h, once > lockdep_assert_held() usage will require xfs_ail definition > - ASSERT XFS_LI_IN_AIL into xfs_clear_li_failed() > - assert inode is flush locked in xfs_inode_item_error > - fix bitwise ops mess > > fs/xfs/xfs_buf_item.c | 34 ++++++++++++++++++++++++++++++++++ > fs/xfs/xfs_buf_item.h | 3 +++ > fs/xfs/xfs_inode_item.c | 45 +++++++++++++++++++++++++++++++++++++++++---- > fs/xfs/xfs_trans.h | 1 + > fs/xfs/xfs_trans_ail.c | 4 ++-- > fs/xfs/xfs_trans_priv.h | 31 +++++++++++++++++++++++++++++++ > 6 files changed, 112 insertions(+), 6 deletions(-) > > diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c > index d6ca7d6..940b0eb 100644 > --- a/fs/xfs/xfs_buf_item.c > +++ b/fs/xfs/xfs_buf_item.c > @@ -1226,3 +1226,37 @@ xfs_buf_iodone( > xfs_trans_ail_delete(ailp, lip, SHUTDOWN_CORRUPT_INCORE); > xfs_buf_item_free(BUF_ITEM(lip)); > } > + > +/* > + * Requeue a failed buffer for writeback > + * > + * Return true if the buffer has been re-queued properly, false otherwise > + */ > +bool > +xfs_buf_resubmit_failed_buffers( > + struct xfs_buf *bp, > + struct xfs_log_item *lip, > + struct list_head *buffer_list) > +{ > + struct xfs_log_item *next; > + bool ret; > + > + /* > + * Clear XFS_LI_FAILED flag from all items before resubmit > + * > + * XFS_LI_FAILED set/clear is protected by xa_lock, caller this > + * function already have it acquired > + */ > + for (; lip; lip = next) { > + next = lip->li_bio_list; > + xfs_clear_li_failed(lip); > + } > + > + /* Add this buffer back to the delayed write list */ > + if (!xfs_buf_delwri_queue(bp, buffer_list)) > + ret = false; > + else > + ret = true; > + > + return ret; return xfs_buf_delwri_queue(bp, buffer_list); ? > +} > diff --git a/fs/xfs/xfs_buf_item.h b/fs/xfs/xfs_buf_item.h > index f7eba99..530686e 100644 > --- a/fs/xfs/xfs_buf_item.h > +++ b/fs/xfs/xfs_buf_item.h > @@ -70,6 +70,9 @@ void xfs_buf_attach_iodone(struct xfs_buf *, > xfs_log_item_t *); > void xfs_buf_iodone_callbacks(struct xfs_buf *); > void xfs_buf_iodone(struct xfs_buf *, struct xfs_log_item *); > +bool xfs_buf_resubmit_failed_buffers(struct xfs_buf *, > + struct xfs_log_item *, > + struct list_head *); > > extern kmem_zone_t *xfs_buf_item_zone; > > diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c > index 08cb7d1..ad7ec64 100644 > --- a/fs/xfs/xfs_inode_item.c > +++ b/fs/xfs/xfs_inode_item.c > @@ -27,6 +27,7 @@ > #include "xfs_error.h" > #include "xfs_trace.h" > #include "xfs_trans_priv.h" > +#include "xfs_buf_item.h" > #include "xfs_log.h" > > > @@ -475,6 +476,21 @@ xfs_inode_item_unpin( > wake_up_bit(&ip->i_flags, __XFS_IPINNED_BIT); > } > > +/* > + * Callback used to mark a buffer with XFS_LI_FAILED when items in the buffer > + * have been failed during writeback "This informs the AIL that the inode is already flush locked on the next push and acquires a hold on the buffer to ensure that it isn't reclaimed before dirty data makes it to disk." > + */ > +STATIC void > +xfs_inode_item_error( > + struct xfs_log_item *lip, > + struct xfs_buf *bp) > +{ > + struct xfs_inode *ip = INODE_ITEM(lip)->ili_inode; > + > + ASSERT(xfs_isiflocked(ip)); > + xfs_set_li_failed(lip, bp); > +} > + > STATIC uint > xfs_inode_item_push( > struct xfs_log_item *lip, > @@ -484,13 +500,28 @@ xfs_inode_item_push( > { > struct xfs_inode_log_item *iip = INODE_ITEM(lip); > struct xfs_inode *ip = iip->ili_inode; > - struct xfs_buf *bp = NULL; > + struct xfs_buf *bp = lip->li_buf; > uint rval = XFS_ITEM_SUCCESS; > int error; > > if (xfs_ipincount(ip) > 0) > return XFS_ITEM_PINNED; > > + /* > + * The buffer containing this item failed to be written back > + * previously. Resubmit the buffer for IO. > + */ > + if (lip->li_flags & XFS_LI_FAILED) { > + if (!xfs_buf_trylock(bp)) > + return XFS_ITEM_LOCKED; Bad indentation. > + > + if (!xfs_buf_resubmit_failed_buffers(bp, lip, buffer_list)) > + rval = XFS_ITEM_FLUSHING; > + > + xfs_buf_unlock(bp); > + return rval; > + } > + > if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) > return XFS_ITEM_LOCKED; > > @@ -622,7 +653,8 @@ static const struct xfs_item_ops xfs_inode_item_ops = { > .iop_unlock = xfs_inode_item_unlock, > .iop_committed = xfs_inode_item_committed, > .iop_push = xfs_inode_item_push, > - .iop_committing = xfs_inode_item_committing > + .iop_committing = xfs_inode_item_committing, > + .iop_error = xfs_inode_item_error > }; > > > @@ -710,7 +742,8 @@ xfs_iflush_done( > * the AIL lock. > */ > iip = INODE_ITEM(blip); > - if (iip->ili_logged && blip->li_lsn == iip->ili_flush_lsn) > + if ((iip->ili_logged && blip->li_lsn == iip->ili_flush_lsn) || > + lip->li_flags & XFS_LI_FAILED) > need_ail++; > > blip = next; > @@ -718,7 +751,8 @@ xfs_iflush_done( > > /* make sure we capture the state of the initial inode. */ > iip = INODE_ITEM(lip); > - if (iip->ili_logged && lip->li_lsn == iip->ili_flush_lsn) > + if ((iip->ili_logged && lip->li_lsn == iip->ili_flush_lsn) || > + lip->li_flags & XFS_LI_FAILED) > need_ail++; > > /* > @@ -739,6 +773,9 @@ xfs_iflush_done( > if (INODE_ITEM(blip)->ili_logged && > blip->li_lsn == INODE_ITEM(blip)->ili_flush_lsn) > mlip_changed |= xfs_ail_delete_one(ailp, blip); > + else { > + xfs_clear_li_failed(blip); > + } > } > > if (mlip_changed) { > diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h > index 442d679..7d62772 100644 > --- a/fs/xfs/xfs_trans.h > +++ b/fs/xfs/xfs_trans.h > @@ -49,6 +49,7 @@ typedef struct xfs_log_item { > struct xfs_ail *li_ailp; /* ptr to AIL */ > uint li_type; /* item type */ > uint li_flags; /* misc flags */ > + struct xfs_buf *li_buf; /* real buffer pointer */ > struct xfs_log_item *li_bio_list; /* buffer item list */ > void (*li_cb)(struct xfs_buf *, > struct xfs_log_item *); > diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c > index 9056c0f..eba21a9 100644 > --- a/fs/xfs/xfs_trans_ail.c > +++ b/fs/xfs/xfs_trans_ail.c > @@ -687,15 +687,15 @@ xfs_trans_ail_update_bulk( > bool > xfs_ail_delete_one( > struct xfs_ail *ailp, > - struct xfs_log_item *lip) > + struct xfs_log_item *lip) > { > struct xfs_log_item *mlip = xfs_ail_min(ailp); > > trace_xfs_ail_delete(lip, mlip->li_lsn, lip->li_lsn); > xfs_ail_delete(ailp, lip); > + xfs_clear_li_failed(lip); > lip->li_flags &= ~XFS_LI_IN_AIL; > lip->li_lsn = 0; > - Unrelated whitespace changes here and above..? Brian > return mlip == lip; > } > > diff --git a/fs/xfs/xfs_trans_priv.h b/fs/xfs/xfs_trans_priv.h > index d91706c..b317a36 100644 > --- a/fs/xfs/xfs_trans_priv.h > +++ b/fs/xfs/xfs_trans_priv.h > @@ -164,4 +164,35 @@ xfs_trans_ail_copy_lsn( > *dst = *src; > } > #endif > + > +static inline void > +xfs_clear_li_failed( > + struct xfs_log_item *lip) > +{ > + struct xfs_buf *bp = lip->li_buf; > + > + ASSERT(lip->li_flags & XFS_LI_IN_AIL); > + lockdep_assert_held(&lip->li_ailp->xa_lock); > + > + if (lip->li_flags & XFS_LI_FAILED) { > + lip->li_flags &= ~XFS_LI_FAILED; > + lip->li_buf = NULL; > + xfs_buf_rele(bp); > + } > +} > + > +static inline void > +xfs_set_li_failed( > + struct xfs_log_item *lip, > + struct xfs_buf *bp) > +{ > + lockdep_assert_held(&lip->li_ailp->xa_lock); > + > + if (!(lip->li_flags & XFS_LI_FAILED)) { > + xfs_buf_hold(bp); > + lip->li_flags |= XFS_LI_FAILED; > + lip->li_buf = bp; > + } > +} > + > #endif /* __XFS_TRANS_PRIV_H__ */ > -- > 2.9.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Jul 19, 2017 at 08:01:14AM -0400, Brian Foster wrote: > On Tue, Jul 18, 2017 at 04:54:15PM +0200, Carlos Maiolino wrote: > > When a buffer has been failed during writeback, the inode items into it > > are kept flush locked, and are never resubmitted due the flush lock, so, > > if any buffer fails to be written, the items in AIL are never written to > > disk and never unlocked. > > > > This causes unmount operation to hang due these items flush locked in AIL, > > but this also causes the items in AIL to never be written back, even when > > the IO device comes back to normal. > > > > I've been testing this patch with a DM-thin device, creating a > > filesystem larger than the real device. > > > > When writing enough data to fill the DM-thin device, XFS receives ENOSPC > > errors from the device, and keep spinning on xfsaild (when 'retry > > forever' configuration is set). > > > > At this point, the filesystem can not be unmounted because of the flush locked > > items in AIL, but worse, the items in AIL are never retried at all > > (once xfs_inode_item_push() will skip the items that are flush locked), > > even if the underlying DM-thin device is expanded to the proper size. > > > > This patch fixes both cases, retrying any item that has been failed > > previously, using the infra-structure provided by the previous patch. > > > > Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> > > --- > > This version looks pretty good to me. I've added a few style nits below > and I need to run some testing, but otherwise the code looks good: > > Reviewed-by: Brian Foster <bfoster@redhat.com> > > > > > V2: > > - Fix XFS_LI_FAILED flag removal > > - Use atomic operations to set and clear XFS_LI_FAILED flag > > - Remove check for XBF_WRITE_FAIL in xfs_inode_item_push > > - Add more comments to the code > > - Add a helper function to resubmit the failed buffers, so this > > can be also used in dquot system without duplicating code > > > > V3: > > - kill xfs_imap_to_bp call using a pointer in the log item to > > hold the buffer address > > - use xa_lock instead of atomic operations to handle log item > > flags > > - Add a hold to the buffer for each log item failed > > - move buffer resubmission up in xfs_inode_item_push() > > > > V4: > > - Remove bflags argument from iop_error callback > > - Remove ip argument from xfs_buf_resubmit_failed_buffers > > - Use helpers to set/clear XFS_LI_FAILED flag > > - remove ->xa_lock from the iop->error callback and move it up > > on the stack, so all log items are processed into a single > > pair of lock/unlock > > > > V5: > > - fix comments > > - move buf_lock from xfs_buf_resubmit_failed_buffers() up to > > xfs_inode_item_push, and use trylock instead > > - assert xa_lock is held in xfs_set/clear_li_failed helpers > > and move such helpers into xfs_trans_priv.h, once > > lockdep_assert_held() usage will require xfs_ail definition > > - ASSERT XFS_LI_IN_AIL into xfs_clear_li_failed() > > - assert inode is flush locked in xfs_inode_item_error > > - fix bitwise ops mess > > > > fs/xfs/xfs_buf_item.c | 34 ++++++++++++++++++++++++++++++++++ > > fs/xfs/xfs_buf_item.h | 3 +++ > > fs/xfs/xfs_inode_item.c | 45 +++++++++++++++++++++++++++++++++++++++++---- > > fs/xfs/xfs_trans.h | 1 + > > fs/xfs/xfs_trans_ail.c | 4 ++-- > > fs/xfs/xfs_trans_priv.h | 31 +++++++++++++++++++++++++++++++ > > 6 files changed, 112 insertions(+), 6 deletions(-) > > > > diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c > > index d6ca7d6..940b0eb 100644 > > --- a/fs/xfs/xfs_buf_item.c > > +++ b/fs/xfs/xfs_buf_item.c > > @@ -1226,3 +1226,37 @@ xfs_buf_iodone( > > xfs_trans_ail_delete(ailp, lip, SHUTDOWN_CORRUPT_INCORE); > > xfs_buf_item_free(BUF_ITEM(lip)); > > } > > + > > +/* > > + * Requeue a failed buffer for writeback > > + * > > + * Return true if the buffer has been re-queued properly, false otherwise > > + */ > > +bool > > +xfs_buf_resubmit_failed_buffers( > > + struct xfs_buf *bp, > > + struct xfs_log_item *lip, > > + struct list_head *buffer_list) > > +{ > > + struct xfs_log_item *next; > > + bool ret; > > + > > + /* > > + * Clear XFS_LI_FAILED flag from all items before resubmit > > + * > > + * XFS_LI_FAILED set/clear is protected by xa_lock, caller this > > + * function already have it acquired > > + */ > > + for (; lip; lip = next) { > > + next = lip->li_bio_list; > > + xfs_clear_li_failed(lip); > > + } > > + > > + /* Add this buffer back to the delayed write list */ > > + if (!xfs_buf_delwri_queue(bp, buffer_list)) > > + ret = false; > > + else > > + ret = true; > > + > > + return ret; > > return xfs_buf_delwri_queue(bp, buffer_list); ? yup, sounds better > > > +} > > diff --git a/fs/xfs/xfs_buf_item.h b/fs/xfs/xfs_buf_item.h > > index f7eba99..530686e 100644 > > --- a/fs/xfs/xfs_buf_item.h > > +++ b/fs/xfs/xfs_buf_item.h > > @@ -70,6 +70,9 @@ void xfs_buf_attach_iodone(struct xfs_buf *, > > xfs_log_item_t *); > > void xfs_buf_iodone_callbacks(struct xfs_buf *); > > void xfs_buf_iodone(struct xfs_buf *, struct xfs_log_item *); > > +bool xfs_buf_resubmit_failed_buffers(struct xfs_buf *, > > + struct xfs_log_item *, > > + struct list_head *); > > > > extern kmem_zone_t *xfs_buf_item_zone; > > > > diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c > > index 08cb7d1..ad7ec64 100644 > > --- a/fs/xfs/xfs_inode_item.c > > +++ b/fs/xfs/xfs_inode_item.c > > @@ -27,6 +27,7 @@ > > #include "xfs_error.h" > > #include "xfs_trace.h" > > #include "xfs_trans_priv.h" > > +#include "xfs_buf_item.h" > > #include "xfs_log.h" > > > > > > @@ -475,6 +476,21 @@ xfs_inode_item_unpin( > > wake_up_bit(&ip->i_flags, __XFS_IPINNED_BIT); > > } > > > > +/* > > + * Callback used to mark a buffer with XFS_LI_FAILED when items in the buffer > > + * have been failed during writeback > > "This informs the AIL that the inode is already flush locked on the next > push and acquires a hold on the buffer to ensure that it isn't reclaimed > before dirty data makes it to disk." > sounds fine > > + */ > > +STATIC void > > +xfs_inode_item_error( > > + struct xfs_log_item *lip, > > + struct xfs_buf *bp) > > +{ > > + struct xfs_inode *ip = INODE_ITEM(lip)->ili_inode; > > + > > + ASSERT(xfs_isiflocked(ip)); > > + xfs_set_li_failed(lip, bp); > > +} > > + > > STATIC uint > > xfs_inode_item_push( > > struct xfs_log_item *lip, > > @@ -484,13 +500,28 @@ xfs_inode_item_push( > > { > > struct xfs_inode_log_item *iip = INODE_ITEM(lip); > > struct xfs_inode *ip = iip->ili_inode; > > - struct xfs_buf *bp = NULL; > > + struct xfs_buf *bp = lip->li_buf; > > uint rval = XFS_ITEM_SUCCESS; > > int error; > > > > if (xfs_ipincount(ip) > 0) > > return XFS_ITEM_PINNED; > > > > + /* > > + * The buffer containing this item failed to be written back > > + * previously. Resubmit the buffer for IO. > > + */ > > + if (lip->li_flags & XFS_LI_FAILED) { > > + if (!xfs_buf_trylock(bp)) > > + return XFS_ITEM_LOCKED; > > Bad indentation. > > > + > > + if (!xfs_buf_resubmit_failed_buffers(bp, lip, buffer_list)) > > + rval = XFS_ITEM_FLUSHING; > > + > > + xfs_buf_unlock(bp); > > + return rval; > > + } > > + > > if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) > > return XFS_ITEM_LOCKED; > > > > @@ -622,7 +653,8 @@ static const struct xfs_item_ops xfs_inode_item_ops = { > > .iop_unlock = xfs_inode_item_unlock, > > .iop_committed = xfs_inode_item_committed, > > .iop_push = xfs_inode_item_push, > > - .iop_committing = xfs_inode_item_committing > > + .iop_committing = xfs_inode_item_committing, > > + .iop_error = xfs_inode_item_error > > }; > > > > > > @@ -710,7 +742,8 @@ xfs_iflush_done( > > * the AIL lock. > > */ > > iip = INODE_ITEM(blip); > > - if (iip->ili_logged && blip->li_lsn == iip->ili_flush_lsn) > > + if ((iip->ili_logged && blip->li_lsn == iip->ili_flush_lsn) || > > + lip->li_flags & XFS_LI_FAILED) > > need_ail++; > > > > blip = next; > > @@ -718,7 +751,8 @@ xfs_iflush_done( > > > > /* make sure we capture the state of the initial inode. */ > > iip = INODE_ITEM(lip); > > - if (iip->ili_logged && lip->li_lsn == iip->ili_flush_lsn) > > + if ((iip->ili_logged && lip->li_lsn == iip->ili_flush_lsn) || > > + lip->li_flags & XFS_LI_FAILED) > > need_ail++; > > > > /* > > @@ -739,6 +773,9 @@ xfs_iflush_done( > > if (INODE_ITEM(blip)->ili_logged && > > blip->li_lsn == INODE_ITEM(blip)->ili_flush_lsn) > > mlip_changed |= xfs_ail_delete_one(ailp, blip); > > + else { > > + xfs_clear_li_failed(blip); > > + } > > } > > > > if (mlip_changed) { > > diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h > > index 442d679..7d62772 100644 > > --- a/fs/xfs/xfs_trans.h > > +++ b/fs/xfs/xfs_trans.h > > @@ -49,6 +49,7 @@ typedef struct xfs_log_item { > > struct xfs_ail *li_ailp; /* ptr to AIL */ > > uint li_type; /* item type */ > > uint li_flags; /* misc flags */ > > + struct xfs_buf *li_buf; /* real buffer pointer */ > > struct xfs_log_item *li_bio_list; /* buffer item list */ > > void (*li_cb)(struct xfs_buf *, > > struct xfs_log_item *); > > diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c > > index 9056c0f..eba21a9 100644 > > --- a/fs/xfs/xfs_trans_ail.c > > +++ b/fs/xfs/xfs_trans_ail.c > > @@ -687,15 +687,15 @@ xfs_trans_ail_update_bulk( > > bool > > xfs_ail_delete_one( > > struct xfs_ail *ailp, > > - struct xfs_log_item *lip) > > + struct xfs_log_item *lip) > > { > > struct xfs_log_item *mlip = xfs_ail_min(ailp); > > > > trace_xfs_ail_delete(lip, mlip->li_lsn, lip->li_lsn); > > xfs_ail_delete(ailp, lip); > > + xfs_clear_li_failed(lip); > > lip->li_flags &= ~XFS_LI_IN_AIL; > > lip->li_lsn = 0; > > - > > Unrelated whitespace changes here and above..? > Thanks, I'll fix these style mistakes and submit it with your review tag too. > Brian > > > return mlip == lip; > > } > > > > diff --git a/fs/xfs/xfs_trans_priv.h b/fs/xfs/xfs_trans_priv.h > > index d91706c..b317a36 100644 > > --- a/fs/xfs/xfs_trans_priv.h > > +++ b/fs/xfs/xfs_trans_priv.h > > @@ -164,4 +164,35 @@ xfs_trans_ail_copy_lsn( > > *dst = *src; > > } > > #endif > > + > > +static inline void > > +xfs_clear_li_failed( > > + struct xfs_log_item *lip) > > +{ > > + struct xfs_buf *bp = lip->li_buf; > > + > > + ASSERT(lip->li_flags & XFS_LI_IN_AIL); > > + lockdep_assert_held(&lip->li_ailp->xa_lock); > > + > > + if (lip->li_flags & XFS_LI_FAILED) { > > + lip->li_flags &= ~XFS_LI_FAILED; > > + lip->li_buf = NULL; > > + xfs_buf_rele(bp); > > + } > > +} > > + > > +static inline void > > +xfs_set_li_failed( > > + struct xfs_log_item *lip, > > + struct xfs_buf *bp) > > +{ > > + lockdep_assert_held(&lip->li_ailp->xa_lock); > > + > > + if (!(lip->li_flags & XFS_LI_FAILED)) { > > + xfs_buf_hold(bp); > > + lip->li_flags |= XFS_LI_FAILED; > > + lip->li_buf = bp; > > + } > > +} > > + > > #endif /* __XFS_TRANS_PRIV_H__ */ > > -- > > 2.9.4 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c index d6ca7d6..940b0eb 100644 --- a/fs/xfs/xfs_buf_item.c +++ b/fs/xfs/xfs_buf_item.c @@ -1226,3 +1226,37 @@ xfs_buf_iodone( xfs_trans_ail_delete(ailp, lip, SHUTDOWN_CORRUPT_INCORE); xfs_buf_item_free(BUF_ITEM(lip)); } + +/* + * Requeue a failed buffer for writeback + * + * Return true if the buffer has been re-queued properly, false otherwise + */ +bool +xfs_buf_resubmit_failed_buffers( + struct xfs_buf *bp, + struct xfs_log_item *lip, + struct list_head *buffer_list) +{ + struct xfs_log_item *next; + bool ret; + + /* + * Clear XFS_LI_FAILED flag from all items before resubmit + * + * XFS_LI_FAILED set/clear is protected by xa_lock, caller this + * function already have it acquired + */ + for (; lip; lip = next) { + next = lip->li_bio_list; + xfs_clear_li_failed(lip); + } + + /* Add this buffer back to the delayed write list */ + if (!xfs_buf_delwri_queue(bp, buffer_list)) + ret = false; + else + ret = true; + + return ret; +} diff --git a/fs/xfs/xfs_buf_item.h b/fs/xfs/xfs_buf_item.h index f7eba99..530686e 100644 --- a/fs/xfs/xfs_buf_item.h +++ b/fs/xfs/xfs_buf_item.h @@ -70,6 +70,9 @@ void xfs_buf_attach_iodone(struct xfs_buf *, xfs_log_item_t *); void xfs_buf_iodone_callbacks(struct xfs_buf *); void xfs_buf_iodone(struct xfs_buf *, struct xfs_log_item *); +bool xfs_buf_resubmit_failed_buffers(struct xfs_buf *, + struct xfs_log_item *, + struct list_head *); extern kmem_zone_t *xfs_buf_item_zone; diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c index 08cb7d1..ad7ec64 100644 --- a/fs/xfs/xfs_inode_item.c +++ b/fs/xfs/xfs_inode_item.c @@ -27,6 +27,7 @@ #include "xfs_error.h" #include "xfs_trace.h" #include "xfs_trans_priv.h" +#include "xfs_buf_item.h" #include "xfs_log.h" @@ -475,6 +476,21 @@ xfs_inode_item_unpin( wake_up_bit(&ip->i_flags, __XFS_IPINNED_BIT); } +/* + * Callback used to mark a buffer with XFS_LI_FAILED when items in the buffer + * have been failed during writeback + */ +STATIC void +xfs_inode_item_error( + struct xfs_log_item *lip, + struct xfs_buf *bp) +{ + struct xfs_inode *ip = INODE_ITEM(lip)->ili_inode; + + ASSERT(xfs_isiflocked(ip)); + xfs_set_li_failed(lip, bp); +} + STATIC uint xfs_inode_item_push( struct xfs_log_item *lip, @@ -484,13 +500,28 @@ xfs_inode_item_push( { struct xfs_inode_log_item *iip = INODE_ITEM(lip); struct xfs_inode *ip = iip->ili_inode; - struct xfs_buf *bp = NULL; + struct xfs_buf *bp = lip->li_buf; uint rval = XFS_ITEM_SUCCESS; int error; if (xfs_ipincount(ip) > 0) return XFS_ITEM_PINNED; + /* + * The buffer containing this item failed to be written back + * previously. Resubmit the buffer for IO. + */ + if (lip->li_flags & XFS_LI_FAILED) { + if (!xfs_buf_trylock(bp)) + return XFS_ITEM_LOCKED; + + if (!xfs_buf_resubmit_failed_buffers(bp, lip, buffer_list)) + rval = XFS_ITEM_FLUSHING; + + xfs_buf_unlock(bp); + return rval; + } + if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) return XFS_ITEM_LOCKED; @@ -622,7 +653,8 @@ static const struct xfs_item_ops xfs_inode_item_ops = { .iop_unlock = xfs_inode_item_unlock, .iop_committed = xfs_inode_item_committed, .iop_push = xfs_inode_item_push, - .iop_committing = xfs_inode_item_committing + .iop_committing = xfs_inode_item_committing, + .iop_error = xfs_inode_item_error }; @@ -710,7 +742,8 @@ xfs_iflush_done( * the AIL lock. */ iip = INODE_ITEM(blip); - if (iip->ili_logged && blip->li_lsn == iip->ili_flush_lsn) + if ((iip->ili_logged && blip->li_lsn == iip->ili_flush_lsn) || + lip->li_flags & XFS_LI_FAILED) need_ail++; blip = next; @@ -718,7 +751,8 @@ xfs_iflush_done( /* make sure we capture the state of the initial inode. */ iip = INODE_ITEM(lip); - if (iip->ili_logged && lip->li_lsn == iip->ili_flush_lsn) + if ((iip->ili_logged && lip->li_lsn == iip->ili_flush_lsn) || + lip->li_flags & XFS_LI_FAILED) need_ail++; /* @@ -739,6 +773,9 @@ xfs_iflush_done( if (INODE_ITEM(blip)->ili_logged && blip->li_lsn == INODE_ITEM(blip)->ili_flush_lsn) mlip_changed |= xfs_ail_delete_one(ailp, blip); + else { + xfs_clear_li_failed(blip); + } } if (mlip_changed) { diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h index 442d679..7d62772 100644 --- a/fs/xfs/xfs_trans.h +++ b/fs/xfs/xfs_trans.h @@ -49,6 +49,7 @@ typedef struct xfs_log_item { struct xfs_ail *li_ailp; /* ptr to AIL */ uint li_type; /* item type */ uint li_flags; /* misc flags */ + struct xfs_buf *li_buf; /* real buffer pointer */ struct xfs_log_item *li_bio_list; /* buffer item list */ void (*li_cb)(struct xfs_buf *, struct xfs_log_item *); diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index 9056c0f..eba21a9 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -687,15 +687,15 @@ xfs_trans_ail_update_bulk( bool xfs_ail_delete_one( struct xfs_ail *ailp, - struct xfs_log_item *lip) + struct xfs_log_item *lip) { struct xfs_log_item *mlip = xfs_ail_min(ailp); trace_xfs_ail_delete(lip, mlip->li_lsn, lip->li_lsn); xfs_ail_delete(ailp, lip); + xfs_clear_li_failed(lip); lip->li_flags &= ~XFS_LI_IN_AIL; lip->li_lsn = 0; - return mlip == lip; } diff --git a/fs/xfs/xfs_trans_priv.h b/fs/xfs/xfs_trans_priv.h index d91706c..b317a36 100644 --- a/fs/xfs/xfs_trans_priv.h +++ b/fs/xfs/xfs_trans_priv.h @@ -164,4 +164,35 @@ xfs_trans_ail_copy_lsn( *dst = *src; } #endif + +static inline void +xfs_clear_li_failed( + struct xfs_log_item *lip) +{ + struct xfs_buf *bp = lip->li_buf; + + ASSERT(lip->li_flags & XFS_LI_IN_AIL); + lockdep_assert_held(&lip->li_ailp->xa_lock); + + if (lip->li_flags & XFS_LI_FAILED) { + lip->li_flags &= ~XFS_LI_FAILED; + lip->li_buf = NULL; + xfs_buf_rele(bp); + } +} + +static inline void +xfs_set_li_failed( + struct xfs_log_item *lip, + struct xfs_buf *bp) +{ + lockdep_assert_held(&lip->li_ailp->xa_lock); + + if (!(lip->li_flags & XFS_LI_FAILED)) { + xfs_buf_hold(bp); + lip->li_flags |= XFS_LI_FAILED; + lip->li_buf = bp; + } +} + #endif /* __XFS_TRANS_PRIV_H__ */
When a buffer has been failed during writeback, the inode items into it are kept flush locked, and are never resubmitted due the flush lock, so, if any buffer fails to be written, the items in AIL are never written to disk and never unlocked. This causes unmount operation to hang due these items flush locked in AIL, but this also causes the items in AIL to never be written back, even when the IO device comes back to normal. I've been testing this patch with a DM-thin device, creating a filesystem larger than the real device. When writing enough data to fill the DM-thin device, XFS receives ENOSPC errors from the device, and keep spinning on xfsaild (when 'retry forever' configuration is set). At this point, the filesystem can not be unmounted because of the flush locked items in AIL, but worse, the items in AIL are never retried at all (once xfs_inode_item_push() will skip the items that are flush locked), even if the underlying DM-thin device is expanded to the proper size. This patch fixes both cases, retrying any item that has been failed previously, using the infra-structure provided by the previous patch. Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> --- V2: - Fix XFS_LI_FAILED flag removal - Use atomic operations to set and clear XFS_LI_FAILED flag - Remove check for XBF_WRITE_FAIL in xfs_inode_item_push - Add more comments to the code - Add a helper function to resubmit the failed buffers, so this can be also used in dquot system without duplicating code V3: - kill xfs_imap_to_bp call using a pointer in the log item to hold the buffer address - use xa_lock instead of atomic operations to handle log item flags - Add a hold to the buffer for each log item failed - move buffer resubmission up in xfs_inode_item_push() V4: - Remove bflags argument from iop_error callback - Remove ip argument from xfs_buf_resubmit_failed_buffers - Use helpers to set/clear XFS_LI_FAILED flag - remove ->xa_lock from the iop->error callback and move it up on the stack, so all log items are processed into a single pair of lock/unlock V5: - fix comments - move buf_lock from xfs_buf_resubmit_failed_buffers() up to xfs_inode_item_push, and use trylock instead - assert xa_lock is held in xfs_set/clear_li_failed helpers and move such helpers into xfs_trans_priv.h, once lockdep_assert_held() usage will require xfs_ail definition - ASSERT XFS_LI_IN_AIL into xfs_clear_li_failed() - assert inode is flush locked in xfs_inode_item_error - fix bitwise ops mess fs/xfs/xfs_buf_item.c | 34 ++++++++++++++++++++++++++++++++++ fs/xfs/xfs_buf_item.h | 3 +++ fs/xfs/xfs_inode_item.c | 45 +++++++++++++++++++++++++++++++++++++++++---- fs/xfs/xfs_trans.h | 1 + fs/xfs/xfs_trans_ail.c | 4 ++-- fs/xfs/xfs_trans_priv.h | 31 +++++++++++++++++++++++++++++++ 6 files changed, 112 insertions(+), 6 deletions(-)