From: Allison Collins <allison.henderson@oracle.com>
To: Chandan Rajendra <chandan@linux.ibm.com>
Cc: linux-xfs@vger.kernel.org
Subject: Re: [PATCH v8 18/20] xfs: Add delay ready attr remove routines
Date: Mon, 20 Apr 2020 16:26:21 -0700 [thread overview]
Message-ID: <4077db7e-faa5-75df-cd32-8496ba378c32@oracle.com> (raw)
In-Reply-To: <1751112.6zseaXoMQ2@localhost.localdomain>
On 4/20/20 2:06 AM, Chandan Rajendra wrote:
> On Saturday, April 4, 2020 3:42 AM Allison Collins wrote:
>> This patch modifies the attr remove routines to be delay ready. This
>> means they no longer roll or commit transactions, but instead return
>> -EAGAIN to have the calling routine roll and refresh the transaction. In
>> this series, xfs_attr_remove_args has become xfs_attr_remove_iter, which
>> uses a sort of state machine like switch to keep track of where it was
>> when EAGAIN was returned. xfs_attr_node_removename has also been
>> modified to use the switch, and a new version of xfs_attr_remove_args
>> consists of a simple loop to refresh the transaction until the operation
>> is completed.
>>
>> Calls to xfs_attr_rmtval_remove are replaced with the delay ready
>> counter parts: xfs_attr_rmtval_invalidate (appearing in the setup
>> helper) and then __xfs_attr_rmtval_remove. We will rename
>> __xfs_attr_rmtval_remove back to xfs_attr_rmtval_remove when we are
>> done.
>>
>> This patch also adds a new struct xfs_delattr_context, which we will use
>> to keep track of the current state of an attribute operation. The new
>> xfs_delattr_state enum is used to track various operations that are in
>> progress so that we know not to repeat them, and resume where we left
>> off before EAGAIN was returned to cycle out the transaction. Other
>> members take the place of local variables that need to retain their
>> values across multiple function recalls.
>>
>> Below is a state machine diagram for attr remove operations. The
>> XFS_DAS_* states indicate places where the function would return
>> -EAGAIN, and then immediately resume from after being recalled by the
>> calling function. States marked as a "subroutine state" indicate that
>> they belong to a subroutine, and so the calling function needs to pass
>> them back to that subroutine to allow it to finish where it left off.
>> But they otherwise do not have a role in the calling function other than
>> just passing through.
>>
>> xfs_attr_remove_iter()
>> XFS_DAS_RM_SHRINK ─┐
>> (subroutine state) │
>> │
>> XFS_DAS_RMTVAL_REMOVE ─┤
>> (subroutine state) │
>> └─>xfs_attr_node_removename()
>> │
>> v
>> need to remove
>> ┌─n── rmt blocks?
>> │ │
>> │ y
>> │ │
>> │ v
>> │ ┌─>XFS_DAS_RMTVAL_REMOVE
>> │ │ │
>> │ │ v
>> │ └──y── more blks
>> │ to remove?
>> │ │
>> │ n
>> │ │
>> │ v
>> │ need to
>> └─────> shrink tree? ─n─┐
>> │ │
>> y │
>> │ │
>> v │
>> XFS_DAS_RM_SHRINK │
>> │ │
>> v │
>> done <─────┘
>>
>> Signed-off-by: Allison Collins <allison.henderson@oracle.com>
>> ---
>> fs/xfs/libxfs/xfs_attr.c | 168 ++++++++++++++++++++++++++++++++++++-----------
>> fs/xfs/libxfs/xfs_attr.h | 38 +++++++++++
>> 2 files changed, 168 insertions(+), 38 deletions(-)
>>
>> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
>> index d735570..f700976 100644
>> --- a/fs/xfs/libxfs/xfs_attr.c
>> +++ b/fs/xfs/libxfs/xfs_attr.c
>> @@ -45,7 +45,7 @@ STATIC int xfs_attr_shortform_addname(xfs_da_args_t *args);
>> */
>> STATIC int xfs_attr_leaf_get(xfs_da_args_t *args);
>> STATIC int xfs_attr_leaf_addname(xfs_da_args_t *args);
>> -STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args);
>> +STATIC int xfs_attr_leaf_removename(struct xfs_delattr_context *dac);
>> STATIC int xfs_attr_leaf_hasname(struct xfs_da_args *args, struct xfs_buf **bp);
>>
>> /*
>> @@ -53,12 +53,21 @@ STATIC int xfs_attr_leaf_hasname(struct xfs_da_args *args, struct xfs_buf **bp);
>> */
>> STATIC int xfs_attr_node_get(xfs_da_args_t *args);
>> STATIC int xfs_attr_node_addname(xfs_da_args_t *args);
>> -STATIC int xfs_attr_node_removename(xfs_da_args_t *args);
>> +STATIC int xfs_attr_node_removename(struct xfs_delattr_context *dac);
>> STATIC int xfs_attr_node_hasname(xfs_da_args_t *args,
>> struct xfs_da_state **state);
>> STATIC int xfs_attr_fillstate(xfs_da_state_t *state);
>> STATIC int xfs_attr_refillstate(xfs_da_state_t *state);
>>
>> +STATIC void
>> +xfs_delattr_context_init(
>> + struct xfs_delattr_context *dac,
>> + struct xfs_da_args *args)
>> +{
>> + memset(dac, 0, sizeof(struct xfs_delattr_context));
>> + dac->da_args = args;
>> +}
>> +
>> int
>> xfs_inode_hasattr(
>> struct xfs_inode *ip)
>> @@ -356,20 +365,66 @@ xfs_has_attr(
>> */
>> int
>> xfs_attr_remove_args(
>> - struct xfs_da_args *args)
>> + struct xfs_da_args *args)
>> {
>> + int error = 0;
>> + struct xfs_delattr_context dac;
>> +
>> + xfs_delattr_context_init(&dac, args);
>> +
>> + do {
>> + error = xfs_attr_remove_iter(&dac);
>> + if (error != -EAGAIN)
>> + break;
>> +
>> + if (dac.flags & XFS_DAC_DEFER_FINISH) {
>> + dac.flags &= ~XFS_DAC_DEFER_FINISH;
>> + error = xfs_defer_finish(&args->trans);
>> + if (error)
>> + break;
>> + }
>> +
>> + error = xfs_trans_roll_inode(&args->trans, args->dp);
>> + if (error)
>> + break;
>> + } while (true);
>> +
>> + return error;
>> +}
>> +
>> +/*
>> + * Remove the attribute specified in @args.
>> + *
>> + * This function may return -EAGAIN to signal that the transaction needs to be
>> + * rolled. Callers should continue calling this function until they receive a
>> + * return value other than -EAGAIN.
>> + */
>> +int
>> +xfs_attr_remove_iter(
>> + struct xfs_delattr_context *dac)
>> +{
>> + struct xfs_da_args *args = dac->da_args;
>> struct xfs_inode *dp = args->dp;
>> int error;
>>
>> + /* State machine switch */
>> + switch (dac->dela_state) {
>> + case XFS_DAS_RM_SHRINK:
>> + case XFS_DAS_RMTVAL_REMOVE:
>> + return xfs_attr_node_removename(dac);
>> + default:
>> + break;
>> + }
>> +
>> if (!xfs_inode_hasattr(dp)) {
>> error = -ENOATTR;
>> } else if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
>> ASSERT(dp->i_afp->if_flags & XFS_IFINLINE);
>> error = xfs_attr_shortform_remove(args);
>> } else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
>> - error = xfs_attr_leaf_removename(args);
>> + error = xfs_attr_leaf_removename(dac);
>> } else {
>> - error = xfs_attr_node_removename(args);
>> + error = xfs_attr_node_removename(dac);
>> }
>>
>> return error;
>> @@ -794,11 +849,12 @@ xfs_attr_leaf_hasname(
>> */
>> STATIC int
>> xfs_attr_leaf_removename(
>> - struct xfs_da_args *args)
>> + struct xfs_delattr_context *dac)
>> {
>> - struct xfs_inode *dp;
>> - struct xfs_buf *bp;
>> - int error, forkoff;
>> + struct xfs_da_args *args = dac->da_args;
>> + struct xfs_inode *dp;
>> + struct xfs_buf *bp;
>> + int error, forkoff;
>>
>> trace_xfs_attr_leaf_removename(args);
>>
>> @@ -825,9 +881,8 @@ xfs_attr_leaf_removename(
>> /* bp is gone due to xfs_da_shrink_inode */
>> if (error)
>> return error;
>> - error = xfs_defer_finish(&args->trans);
>> - if (error)
>> - return error;
>> +
>> + dac->flags |= XFS_DAC_DEFER_FINISH;
>> }
>> return 0;
>> }
>> @@ -1128,12 +1183,13 @@ xfs_attr_node_addname(
>> */
>> STATIC int
>> xfs_attr_node_shrink(
>> - struct xfs_da_args *args,
>> - struct xfs_da_state *state)
>> + struct xfs_delattr_context *dac,
>> + struct xfs_da_state *state)
>> {
>> - struct xfs_inode *dp = args->dp;
>> - int error, forkoff;
>> - struct xfs_buf *bp;
>> + struct xfs_da_args *args = dac->da_args;
>> + struct xfs_inode *dp = args->dp;
>> + int error, forkoff;
>> + struct xfs_buf *bp;
>>
>> /*
>> * Have to get rid of the copy of this dabuf in the state.
>> @@ -1153,9 +1209,7 @@ xfs_attr_node_shrink(
>> if (error)
>> return error;
>>
>> - error = xfs_defer_finish(&args->trans);
>> - if (error)
>> - return error;
>> + dac->flags |= XFS_DAC_DEFER_FINISH;
>> } else
>> xfs_trans_brelse(args->trans, bp);
>>
>> @@ -1194,13 +1248,15 @@ xfs_attr_leaf_mark_incomplete(
>>
>> /*
>> * Initial setup for xfs_attr_node_removename. Make sure the attr is there and
>> - * the blocks are valid. Any remote blocks will be marked incomplete.
>> + * the blocks are valid. Any remote blocks will be marked incomplete and
>> + * invalidated.
>> */
>> STATIC
>> int xfs_attr_node_removename_setup(
>> - struct xfs_da_args *args,
>> - struct xfs_da_state **state)
>> + struct xfs_delattr_context *dac,
>> + struct xfs_da_state **state)
>> {
>> + struct xfs_da_args *args = dac->da_args;
>> int error;
>> struct xfs_da_state_blk *blk;
>>
>> @@ -1212,10 +1268,21 @@ int xfs_attr_node_removename_setup(
>> ASSERT(blk->bp != NULL);
>> ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
>>
>> + /*
>> + * Store blk and state in the context incase we need to cycle out the
>> + * transaction
>> + */
>> + dac->blk = blk;
>> + dac->da_state = *state;
>> +
>> if (args->rmtblkno > 0) {
>> error = xfs_attr_leaf_mark_incomplete(args, *state);
>> if (error)
>> return error;
>> +
>> + error = xfs_attr_rmtval_invalidate(args);
>> + if (error)
>> + return error;
>> }
>>
>> return 0;
>> @@ -1228,7 +1295,10 @@ xfs_attr_node_removename_rmt (
>> {
>> int error = 0;
>>
>> - error = xfs_attr_rmtval_remove(args);
>> + /*
>> + * May return -EAGAIN to request that the caller recall this function
>> + */
>> + error = __xfs_attr_rmtval_remove(args);
>> if (error)
>> return error;
>>
>> @@ -1249,19 +1319,37 @@ xfs_attr_node_removename_rmt (
>> * This will involve walking down the Btree, and may involve joining
>> * leaf nodes and even joining intermediate nodes up to and including
>> * the root node (a special case of an intermediate node).
>> + *
>> + * This routine is meant to function as either an inline or delayed operation,
>> + * and may return -EAGAIN when the transaction needs to be rolled. Calling
>> + * functions will need to handle this, and recall the function until a
>> + * successful error code is returned.
>> */
>> STATIC int
>> xfs_attr_node_removename(
>> - struct xfs_da_args *args)
>> + struct xfs_delattr_context *dac)
>> {
>> + struct xfs_da_args *args = dac->da_args;
>> struct xfs_da_state *state;
>> struct xfs_da_state_blk *blk;
>> int retval, error;
>> struct xfs_inode *dp = args->dp;
>>
>> trace_xfs_attr_node_removename(args);
>> + state = dac->da_state;
>> + blk = dac->blk;
>> +
>> + /* State machine switch */
>> + switch (dac->dela_state) {
>> + case XFS_DAS_RMTVAL_REMOVE:
>> + goto das_rmtval_remove;
>> + case XFS_DAS_RM_SHRINK:
>> + goto das_rm_shrink;
>> + default:
>> + break;
>> + }
>>
>> - error = xfs_attr_node_removename_setup(args, &state);
>> + error = xfs_attr_node_removename_setup(dac, &state);
>> if (error)
>> goto out;
>>
>> @@ -1270,10 +1358,16 @@ xfs_attr_node_removename(
>> * This is done before we remove the attribute so that we don't
>> * overflow the maximum size of a transaction and/or hit a deadlock.
>> */
>> +
>> +das_rmtval_remove:
>> +
>> if (args->rmtblkno > 0) {
>> error = xfs_attr_node_removename_rmt(args, state);
>> - if (error)
>> - goto out;
>> + if (error) {
>> + if (error == -EAGAIN)
>> + dac->dela_state = XFS_DAS_RMTVAL_REMOVE;
>
> Shouldn't XFS_DAC_DEFER_FINISH be set in dac->flags?
> xfs_attr_node_removename_rmt() indirectly calls __xfs_bunmapi() which would
> have added items to the deferred list.
>
Ok I see it. I think what I'll do based on the over all v8 feed back
is: make __xfs_attr_rmtval_remove a helper function of
xfs_attr_rmtval_remove in patch 10. I'll keep the xfs_defer_finish as
part of that helper. Then when we come to this patch, the
xfs_defer_finish will turn into the flag set. That should fix this I
believe. Thank for the review!
Allison
next prev parent reply other threads:[~2020-04-20 23:26 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-03 22:12 [PATCH v8 00/20] xfs: Delay Ready Attributes Allison Collins
2020-04-03 22:12 ` [PATCH v8 01/20] xfs: Add xfs_has_attr and subroutines Allison Collins
2020-04-06 14:31 ` Brian Foster
2020-04-06 22:09 ` Allison Collins
2020-04-03 22:12 ` [PATCH v8 02/20] xfs: Check for -ENOATTR or -EEXIST Allison Collins
2020-04-06 14:31 ` Brian Foster
2020-04-06 23:14 ` Allison Collins
2020-04-15 6:43 ` Chandan Rajendra
2020-04-03 22:12 ` [PATCH v8 03/20] xfs: Factor out new helper functions xfs_attr_rmtval_set Allison Collins
2020-04-03 22:12 ` [PATCH v8 04/20] xfs: Pull up trans handling in xfs_attr3_leaf_flipflags Allison Collins
2020-04-03 22:12 ` [PATCH v8 05/20] xfs: Split apart xfs_attr_leaf_addname Allison Collins
2020-04-03 22:12 ` [PATCH v8 06/20] xfs: Refactor xfs_attr_try_sf_addname Allison Collins
2020-04-03 22:12 ` [PATCH v8 07/20] xfs: Pull up trans roll from xfs_attr3_leaf_setflag Allison Collins
2020-04-03 22:12 ` [PATCH v8 08/20] xfs: Factor out xfs_attr_rmtval_invalidate Allison Collins
2020-04-03 22:12 ` [PATCH v8 09/20] xfs: Pull up trans roll in xfs_attr3_leaf_clearflag Allison Collins
2020-04-03 22:12 ` [PATCH v8 10/20] xfs: Add helper function __xfs_attr_rmtval_remove Allison Collins
2020-04-07 14:16 ` Brian Foster
2020-04-07 22:19 ` Allison Collins
2020-04-29 23:05 ` Darrick J. Wong
2020-04-29 23:09 ` Darrick J. Wong
2020-04-03 22:12 ` [PATCH v8 11/20] xfs: Add helper function xfs_attr_node_shrink Allison Collins
2020-04-07 14:17 ` Brian Foster
2020-04-07 21:52 ` Allison Collins
2020-04-15 10:16 ` Chandan Rajendra
2020-04-15 22:13 ` Allison Collins
2020-04-03 22:12 ` [PATCH v8 12/20] xfs: Removed unneeded xfs_trans_roll_inode calls Allison Collins
2020-04-07 14:17 ` Brian Foster
2020-04-07 21:53 ` Allison Collins
2020-04-03 22:12 ` [PATCH v8 13/20] xfs: Add helpers xfs_attr_is_shortform and xfs_attr_set_shortform Allison Collins
2020-04-07 15:23 ` Brian Foster
2020-04-07 21:53 ` Allison Collins
2020-04-10 16:55 ` Allison Collins
2020-04-11 12:57 ` Brian Foster
2020-04-20 5:30 ` Chandan Rajendra
2020-04-20 22:45 ` Allison Collins
2020-04-03 22:12 ` [PATCH v8 14/20] xfs: Add helper function xfs_attr_leaf_mark_incomplete Allison Collins
2020-04-07 15:23 ` Brian Foster
2020-04-07 21:53 ` Allison Collins
2020-04-03 22:12 ` [PATCH v8 15/20] xfs: Add remote block helper functions Allison Collins
2020-04-08 12:09 ` Brian Foster
2020-04-08 16:32 ` Allison Collins
2020-04-03 22:12 ` [PATCH v8 16/20] xfs: Add helper function xfs_attr_node_removename_setup Allison Collins
2020-04-08 12:09 ` Brian Foster
2020-04-08 16:32 ` Allison Collins
2020-04-20 6:25 ` Chandan Rajendra
2020-04-20 22:46 ` Allison Collins
2020-04-03 22:12 ` [PATCH v8 17/20] xfs: Add helper function xfs_attr_node_removename_rmt Allison Collins
2020-04-08 12:10 ` Brian Foster
2020-04-08 16:32 ` Allison Collins
2020-04-20 6:38 ` Chandan Rajendra
2020-04-20 22:46 ` Allison Collins
2020-04-03 22:12 ` [PATCH v8 18/20] xfs: Add delay ready attr remove routines Allison Collins
2020-04-13 12:30 ` Brian Foster
2020-04-14 21:35 ` Allison Collins
2020-04-15 11:46 ` Brian Foster
2020-04-16 3:17 ` Allison Collins
2020-04-16 10:58 ` Brian Foster
2020-04-16 22:41 ` Allison Collins
2020-04-20 9:06 ` Chandan Rajendra
2020-04-20 23:26 ` Allison Collins [this message]
2020-04-03 22:12 ` [PATCH v8 19/20] xfs: Add delay ready attr set routines Allison Collins
2020-04-13 13:40 ` Brian Foster
2020-04-15 22:08 ` Allison Collins
2020-04-16 11:01 ` Brian Foster
2020-04-16 22:54 ` Allison Collins
2020-04-17 10:36 ` Brian Foster
2020-04-20 11:45 ` Chandan Rajendra
2020-04-20 16:20 ` Brian Foster
2020-04-20 23:26 ` Allison Collins
2020-04-03 22:12 ` [PATCH v8 20/20] xfs: Rename __xfs_attr_rmtval_remove Allison Collins
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