| Message ID | 20210416092045.2215-11-allison.henderson@oracle.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | xfs: Delay Ready Attributes | expand |
On 16 Apr 2021 at 14:50, Allison Henderson 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 is merged with > xfs_attr_node_removename become a new function, xfs_attr_remove_iter. > This new version uses a sort of state machine like switch to keep track > of where it was when EAGAIN was returned. A new version of > xfs_attr_remove_args consists of a simple loop to refresh the > transaction until the operation is completed. A new XFS_DAC_DEFER_FINISH > flag is used to finish the transaction where ever the existing code used > to. > > Calls to xfs_attr_rmtval_remove are replaced with the delay ready > version __xfs_attr_rmtval_remove. We will rename > __xfs_attr_rmtval_remove back to xfs_attr_rmtval_remove when we are > done. > > xfs_attr_rmtval_remove itself is still in use by the set routines (used > during a rename). For reasons of preserving existing function, we > modify xfs_attr_rmtval_remove to call xfs_defer_finish when the flag is > set. Similar to how xfs_attr_remove_args does here. Once we transition > the set routines to be delay ready, xfs_attr_rmtval_remove is no longer > used and will be removed. > > 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. See xfs_attr.h for a more > detailed diagram of the states. > > Signed-off-by: Allison Henderson <allison.henderson@oracle.com> > --- > fs/xfs/libxfs/xfs_attr.c | 208 +++++++++++++++++++++++++++------------- > fs/xfs/libxfs/xfs_attr.h | 131 +++++++++++++++++++++++++ > fs/xfs/libxfs/xfs_attr_leaf.c | 2 +- > fs/xfs/libxfs/xfs_attr_remote.c | 48 ++++++---- > fs/xfs/libxfs/xfs_attr_remote.h | 2 +- > fs/xfs/xfs_attr_inactive.c | 2 +- > 6 files changed, 305 insertions(+), 88 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c > index ed06b60..0bea8dd 100644 > --- a/fs/xfs/libxfs/xfs_attr.c > +++ b/fs/xfs/libxfs/xfs_attr.c > @@ -57,7 +57,6 @@ STATIC int xfs_attr_node_addname(struct xfs_da_args *args, > struct xfs_da_state *state); > STATIC int xfs_attr_node_addname_find_attr(struct xfs_da_args *args, > struct xfs_da_state **state); > -STATIC int xfs_attr_node_removename(xfs_da_args_t *args); > STATIC int xfs_attr_node_addname_clear_incomplete(struct xfs_da_args *args); > STATIC int xfs_attr_node_hasname(xfs_da_args_t *args, > struct xfs_da_state **state); > @@ -221,6 +220,31 @@ xfs_attr_is_shortform( > ip->i_afp->if_nextents == 0); > } > > +/* > + * Checks to see if a delayed attribute transaction should be rolled. If so, > + * transaction is finished or rolled as needed. > + */ > +int > +xfs_attr_trans_roll( > + struct xfs_delattr_context *dac) > +{ > + struct xfs_da_args *args = dac->da_args; > + int error; > + > + if (dac->flags & XFS_DAC_DEFER_FINISH) { > + /* > + * The caller wants us to finish all the deferred ops so that we > + * avoid pinning the log tail with a large number of deferred > + * ops. > + */ > + dac->flags &= ~XFS_DAC_DEFER_FINISH; > + error = xfs_defer_finish(&args->trans); > + } else > + error = xfs_trans_roll_inode(&args->trans, args->dp); > + > + return error; > +} > + > STATIC int > xfs_attr_set_fmt( > struct xfs_da_args *args) > @@ -527,21 +551,23 @@ xfs_has_attr( > */ > int > xfs_attr_remove_args( > - struct xfs_da_args *args) > + struct xfs_da_args *args) > { > - struct xfs_inode *dp = args->dp; > - int error; > + int error; > + struct xfs_delattr_context dac = { > + .da_args = args, > + }; > > - if (!xfs_inode_hasattr(dp)) { > - error = -ENOATTR; > - } else if (dp->i_afp->if_format == 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); > - } else { > - error = xfs_attr_node_removename(args); > - } > + do { > + error = xfs_attr_remove_iter(&dac); > + if (error != -EAGAIN) > + break; > + > + error = xfs_attr_trans_roll(&dac); > + if (error) > + return error; > + > + } while (true); > > return error; > } > @@ -1187,14 +1213,16 @@ xfs_attr_leaf_mark_incomplete( > */ > STATIC > int xfs_attr_node_removename_setup( > - struct xfs_da_args *args, > - struct xfs_da_state **state) > + struct xfs_delattr_context *dac) > { > - int error; > + struct xfs_da_args *args = dac->da_args; > + struct xfs_da_state **state = &dac->da_state; > + int error; > > error = xfs_attr_node_hasname(args, state); > if (error != -EEXIST) > return error; > + error = 0; > > ASSERT((*state)->path.blk[(*state)->path.active - 1].bp != NULL); > ASSERT((*state)->path.blk[(*state)->path.active - 1].magic == > @@ -1203,10 +1231,13 @@ int xfs_attr_node_removename_setup( > if (args->rmtblkno > 0) { > error = xfs_attr_leaf_mark_incomplete(args, *state); > if (error) > - return error; > + goto out; > > - return xfs_attr_rmtval_invalidate(args); > + error = xfs_attr_rmtval_invalidate(args); > } > +out: > + if (error) > + xfs_da_state_free(*state); > > return 0; The above should be "return error". Otherwise, we might be missing out on reporting failures from xfs_attr_leaf_mark_incomplete() or xfs_attr_rmtval_invalidate(). > } > @@ -1231,70 +1262,117 @@ xfs_attr_node_remove_cleanup( > } > > /* > - * Remove a name from a B-tree attribute list. > + * Remove the attribute specified in @args. > * > * 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 in-line 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) > +int > +xfs_attr_remove_iter( > + struct xfs_delattr_context *dac) > { > - struct xfs_da_state *state; > - int retval, error; > - struct xfs_inode *dp = args->dp; > + struct xfs_da_args *args = dac->da_args; > + struct xfs_da_state *state = dac->da_state; > + int retval, error; > + struct xfs_inode *dp = args->dp; > > trace_xfs_attr_node_removename(args); > > - error = xfs_attr_node_removename_setup(args, &state); > - if (error) > - goto out; > + switch (dac->dela_state) { > + case XFS_DAS_UNINIT: > + if (!xfs_inode_hasattr(dp)) > + return -ENOATTR; > > - /* > - * If there is an out-of-line value, de-allocate the blocks. > - * 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. > - */ > - if (args->rmtblkno > 0) { > - error = xfs_attr_rmtval_remove(args); > - if (error) > - goto out; > + if (dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL) { > + ASSERT(dp->i_afp->if_flags & XFS_IFINLINE); > + return xfs_attr_shortform_remove(args); > + } > + > + if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) > + return xfs_attr_leaf_removename(args); > + > + if (!dac->da_state) { > + error = xfs_attr_node_removename_setup(dac); > + if (error) > + return error; > + state = dac->da_state; > + } > + > + /* fallthrough */ > + case XFS_DAS_RMTBLK: > + dac->dela_state = XFS_DAS_RMTBLK; > > /* > - * Refill the state structure with buffers, the prior calls > - * released our buffers. > + * If there is an out-of-line value, de-allocate the blocks. > + * 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. > */ > - error = xfs_attr_refillstate(state); > - if (error) > - goto out; > - } > - retval = xfs_attr_node_remove_cleanup(args, state); > + if (args->rmtblkno > 0) { > + /* > + * May return -EAGAIN. Remove blocks until 0 is returned > + */ > + error = __xfs_attr_rmtval_remove(dac); > + if (error == -EAGAIN) > + return error; > + else if (error) > + goto out; > + > + /* > + * Refill the state structure with buffers, the prior > + * calls released our buffers. > + */ > + ASSERT(args->rmtblkno == 0); > + error = xfs_attr_refillstate(state); > + if (error) > + goto out; > + > + dac->dela_state = XFS_DAS_CLNUP; > + dac->flags |= XFS_DAC_DEFER_FINISH; > + return -EAGAIN; > + } > + > + case XFS_DAS_CLNUP: > + retval = xfs_attr_node_remove_cleanup(args, state); > > - /* > - * Check to see if the tree needs to be collapsed. > - */ > - if (retval && (state->path.active > 1)) { > - error = xfs_da3_join(state); > - if (error) > - goto out; > - error = xfs_defer_finish(&args->trans); > - if (error) > - goto out; > /* > - * Commit the Btree join operation and start a new trans. > + * Check to see if the tree needs to be collapsed. Set the flag > + * to indicate that the calling function needs to move the > + * shrink operation > */ > - error = xfs_trans_roll_inode(&args->trans, dp); > - if (error) > - goto out; > - } > + if (retval && (state->path.active > 1)) { > + error = xfs_da3_join(state); > + if (error) > + goto out; > > - /* > - * If the result is small enough, push it all into the inode. > - */ > - if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) > - error = xfs_attr_node_shrink(args, state); > + dac->flags |= XFS_DAC_DEFER_FINISH; > + dac->dela_state = XFS_DAS_RM_SHRINK; > + return -EAGAIN; > + } > + > + /* fallthrough */ > + case XFS_DAS_RM_SHRINK: > + /* > + * If the result is small enough, push it all into the inode. > + */ > + if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) > + error = xfs_attr_node_shrink(args, state); > + > + break; > + default: > + ASSERT(0); > + error = -EINVAL; > + goto out; > + } > > + if (error == -EAGAIN) > + return error; The above two statements probably not required. AFAICT, the call to xfs_attr_node_shrink() is the only instance which can cause "error" to have a non-zero return value if control reaches this point in the function. All other locations in the function seem to either return from the function or jump to "out" label on detecting an error. > out: > if (state) > xfs_da_state_free(state); -- chandan
On 4/18/21 11:53 PM, Chandan Babu R wrote: > On 16 Apr 2021 at 14:50, Allison Henderson 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 is merged with >> xfs_attr_node_removename become a new function, xfs_attr_remove_iter. >> This new version uses a sort of state machine like switch to keep track >> of where it was when EAGAIN was returned. A new version of >> xfs_attr_remove_args consists of a simple loop to refresh the >> transaction until the operation is completed. A new XFS_DAC_DEFER_FINISH >> flag is used to finish the transaction where ever the existing code used >> to. >> >> Calls to xfs_attr_rmtval_remove are replaced with the delay ready >> version __xfs_attr_rmtval_remove. We will rename >> __xfs_attr_rmtval_remove back to xfs_attr_rmtval_remove when we are >> done. >> >> xfs_attr_rmtval_remove itself is still in use by the set routines (used >> during a rename). For reasons of preserving existing function, we >> modify xfs_attr_rmtval_remove to call xfs_defer_finish when the flag is >> set. Similar to how xfs_attr_remove_args does here. Once we transition >> the set routines to be delay ready, xfs_attr_rmtval_remove is no longer >> used and will be removed. >> >> 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. See xfs_attr.h for a more >> detailed diagram of the states. >> >> Signed-off-by: Allison Henderson <allison.henderson@oracle.com> >> --- >> fs/xfs/libxfs/xfs_attr.c | 208 +++++++++++++++++++++++++++------------- >> fs/xfs/libxfs/xfs_attr.h | 131 +++++++++++++++++++++++++ >> fs/xfs/libxfs/xfs_attr_leaf.c | 2 +- >> fs/xfs/libxfs/xfs_attr_remote.c | 48 ++++++---- >> fs/xfs/libxfs/xfs_attr_remote.h | 2 +- >> fs/xfs/xfs_attr_inactive.c | 2 +- >> 6 files changed, 305 insertions(+), 88 deletions(-) >> >> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c >> index ed06b60..0bea8dd 100644 >> --- a/fs/xfs/libxfs/xfs_attr.c >> +++ b/fs/xfs/libxfs/xfs_attr.c >> @@ -57,7 +57,6 @@ STATIC int xfs_attr_node_addname(struct xfs_da_args *args, >> struct xfs_da_state *state); >> STATIC int xfs_attr_node_addname_find_attr(struct xfs_da_args *args, >> struct xfs_da_state **state); >> -STATIC int xfs_attr_node_removename(xfs_da_args_t *args); >> STATIC int xfs_attr_node_addname_clear_incomplete(struct xfs_da_args *args); >> STATIC int xfs_attr_node_hasname(xfs_da_args_t *args, >> struct xfs_da_state **state); >> @@ -221,6 +220,31 @@ xfs_attr_is_shortform( >> ip->i_afp->if_nextents == 0); >> } >> >> +/* >> + * Checks to see if a delayed attribute transaction should be rolled. If so, >> + * transaction is finished or rolled as needed. >> + */ >> +int >> +xfs_attr_trans_roll( >> + struct xfs_delattr_context *dac) >> +{ >> + struct xfs_da_args *args = dac->da_args; >> + int error; >> + >> + if (dac->flags & XFS_DAC_DEFER_FINISH) { >> + /* >> + * The caller wants us to finish all the deferred ops so that we >> + * avoid pinning the log tail with a large number of deferred >> + * ops. >> + */ >> + dac->flags &= ~XFS_DAC_DEFER_FINISH; >> + error = xfs_defer_finish(&args->trans); >> + } else >> + error = xfs_trans_roll_inode(&args->trans, args->dp); >> + >> + return error; >> +} >> + >> STATIC int >> xfs_attr_set_fmt( >> struct xfs_da_args *args) >> @@ -527,21 +551,23 @@ xfs_has_attr( >> */ >> int >> xfs_attr_remove_args( >> - struct xfs_da_args *args) >> + struct xfs_da_args *args) >> { >> - struct xfs_inode *dp = args->dp; >> - int error; >> + int error; >> + struct xfs_delattr_context dac = { >> + .da_args = args, >> + }; >> >> - if (!xfs_inode_hasattr(dp)) { >> - error = -ENOATTR; >> - } else if (dp->i_afp->if_format == 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); >> - } else { >> - error = xfs_attr_node_removename(args); >> - } >> + do { >> + error = xfs_attr_remove_iter(&dac); >> + if (error != -EAGAIN) >> + break; >> + >> + error = xfs_attr_trans_roll(&dac); >> + if (error) >> + return error; >> + >> + } while (true); >> >> return error; >> } >> @@ -1187,14 +1213,16 @@ xfs_attr_leaf_mark_incomplete( >> */ >> STATIC >> int xfs_attr_node_removename_setup( >> - struct xfs_da_args *args, >> - struct xfs_da_state **state) >> + struct xfs_delattr_context *dac) >> { >> - int error; >> + struct xfs_da_args *args = dac->da_args; >> + struct xfs_da_state **state = &dac->da_state; >> + int error; >> >> error = xfs_attr_node_hasname(args, state); >> if (error != -EEXIST) >> return error; >> + error = 0; >> >> ASSERT((*state)->path.blk[(*state)->path.active - 1].bp != NULL); >> ASSERT((*state)->path.blk[(*state)->path.active - 1].magic == >> @@ -1203,10 +1231,13 @@ int xfs_attr_node_removename_setup( >> if (args->rmtblkno > 0) { >> error = xfs_attr_leaf_mark_incomplete(args, *state); >> if (error) >> - return error; >> + goto out; >> >> - return xfs_attr_rmtval_invalidate(args); >> + error = xfs_attr_rmtval_invalidate(args); >> } >> +out: >> + if (error) >> + xfs_da_state_free(*state); >> >> return 0; > > The above should be "return error". Otherwise, we might be missing out on > reporting failures from xfs_attr_leaf_mark_incomplete() or > xfs_attr_rmtval_invalidate(). Ok, will update the return > >> } >> @@ -1231,70 +1262,117 @@ xfs_attr_node_remove_cleanup( >> } >> >> /* >> - * Remove a name from a B-tree attribute list. >> + * Remove the attribute specified in @args. >> * >> * 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 in-line 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) >> +int >> +xfs_attr_remove_iter( >> + struct xfs_delattr_context *dac) >> { >> - struct xfs_da_state *state; >> - int retval, error; >> - struct xfs_inode *dp = args->dp; >> + struct xfs_da_args *args = dac->da_args; >> + struct xfs_da_state *state = dac->da_state; >> + int retval, error; >> + struct xfs_inode *dp = args->dp; >> >> trace_xfs_attr_node_removename(args); >> >> - error = xfs_attr_node_removename_setup(args, &state); >> - if (error) >> - goto out; >> + switch (dac->dela_state) { >> + case XFS_DAS_UNINIT: >> + if (!xfs_inode_hasattr(dp)) >> + return -ENOATTR; >> >> - /* >> - * If there is an out-of-line value, de-allocate the blocks. >> - * 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. >> - */ >> - if (args->rmtblkno > 0) { >> - error = xfs_attr_rmtval_remove(args); >> - if (error) >> - goto out; >> + if (dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL) { >> + ASSERT(dp->i_afp->if_flags & XFS_IFINLINE); >> + return xfs_attr_shortform_remove(args); >> + } >> + >> + if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) >> + return xfs_attr_leaf_removename(args); >> + >> + if (!dac->da_state) { >> + error = xfs_attr_node_removename_setup(dac); >> + if (error) >> + return error; >> + state = dac->da_state; >> + } >> + >> + /* fallthrough */ >> + case XFS_DAS_RMTBLK: >> + dac->dela_state = XFS_DAS_RMTBLK; >> >> /* >> - * Refill the state structure with buffers, the prior calls >> - * released our buffers. >> + * If there is an out-of-line value, de-allocate the blocks. >> + * 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. >> */ >> - error = xfs_attr_refillstate(state); >> - if (error) >> - goto out; >> - } >> - retval = xfs_attr_node_remove_cleanup(args, state); >> + if (args->rmtblkno > 0) { >> + /* >> + * May return -EAGAIN. Remove blocks until 0 is returned >> + */ >> + error = __xfs_attr_rmtval_remove(dac); >> + if (error == -EAGAIN) >> + return error; >> + else if (error) >> + goto out; >> + >> + /* >> + * Refill the state structure with buffers, the prior >> + * calls released our buffers. >> + */ >> + ASSERT(args->rmtblkno == 0); >> + error = xfs_attr_refillstate(state); >> + if (error) >> + goto out; >> + >> + dac->dela_state = XFS_DAS_CLNUP; >> + dac->flags |= XFS_DAC_DEFER_FINISH; >> + return -EAGAIN; >> + } >> + >> + case XFS_DAS_CLNUP: >> + retval = xfs_attr_node_remove_cleanup(args, state); >> >> - /* >> - * Check to see if the tree needs to be collapsed. >> - */ >> - if (retval && (state->path.active > 1)) { >> - error = xfs_da3_join(state); >> - if (error) >> - goto out; >> - error = xfs_defer_finish(&args->trans); >> - if (error) >> - goto out; >> /* >> - * Commit the Btree join operation and start a new trans. >> + * Check to see if the tree needs to be collapsed. Set the flag >> + * to indicate that the calling function needs to move the >> + * shrink operation >> */ >> - error = xfs_trans_roll_inode(&args->trans, dp); >> - if (error) >> - goto out; >> - } >> + if (retval && (state->path.active > 1)) { >> + error = xfs_da3_join(state); >> + if (error) >> + goto out; >> >> - /* >> - * If the result is small enough, push it all into the inode. >> - */ >> - if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) >> - error = xfs_attr_node_shrink(args, state); >> + dac->flags |= XFS_DAC_DEFER_FINISH; >> + dac->dela_state = XFS_DAS_RM_SHRINK; >> + return -EAGAIN; >> + } >> + >> + /* fallthrough */ >> + case XFS_DAS_RM_SHRINK: >> + /* >> + * If the result is small enough, push it all into the inode. >> + */ >> + if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) >> + error = xfs_attr_node_shrink(args, state); >> + >> + break; >> + default: >> + ASSERT(0); >> + error = -EINVAL; >> + goto out; >> + } >> >> + if (error == -EAGAIN) >> + return error; > > The above two statements probably not required. AFAICT, the call to > xfs_attr_node_shrink() is the only instance which can cause "error" to have a > non-zero return value if control reaches this point in the function. All other > locations in the function seem to either return from the function or jump to > "out" label on detecting an error. Ok, i suppose it doesnt hurt anything, but i'll go ahead and bump it since I need to pick up the change above. > >> out: >> if (state) >> xfs_da_state_free(state); > > -- > chandan Thanks for the reviews! Allison >
On Fri, Apr 16, 2021 at 02:20:44AM -0700, Allison Henderson 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 is merged with > xfs_attr_node_removename become a new function, xfs_attr_remove_iter. > This new version uses a sort of state machine like switch to keep track > of where it was when EAGAIN was returned. A new version of > xfs_attr_remove_args consists of a simple loop to refresh the > transaction until the operation is completed. A new XFS_DAC_DEFER_FINISH > flag is used to finish the transaction where ever the existing code used > to. > > Calls to xfs_attr_rmtval_remove are replaced with the delay ready > version __xfs_attr_rmtval_remove. We will rename > __xfs_attr_rmtval_remove back to xfs_attr_rmtval_remove when we are > done. > > xfs_attr_rmtval_remove itself is still in use by the set routines (used > during a rename). For reasons of preserving existing function, we > modify xfs_attr_rmtval_remove to call xfs_defer_finish when the flag is > set. Similar to how xfs_attr_remove_args does here. Once we transition > the set routines to be delay ready, xfs_attr_rmtval_remove is no longer > used and will be removed. > > 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. See xfs_attr.h for a more > detailed diagram of the states. > > Signed-off-by: Allison Henderson <allison.henderson@oracle.com> > --- > fs/xfs/libxfs/xfs_attr.c | 208 +++++++++++++++++++++++++++------------- > fs/xfs/libxfs/xfs_attr.h | 131 +++++++++++++++++++++++++ > fs/xfs/libxfs/xfs_attr_leaf.c | 2 +- > fs/xfs/libxfs/xfs_attr_remote.c | 48 ++++++---- > fs/xfs/libxfs/xfs_attr_remote.h | 2 +- > fs/xfs/xfs_attr_inactive.c | 2 +- > 6 files changed, 305 insertions(+), 88 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c > index ed06b60..0bea8dd 100644 > --- a/fs/xfs/libxfs/xfs_attr.c > +++ b/fs/xfs/libxfs/xfs_attr.c ... > @@ -1231,70 +1262,117 @@ xfs_attr_node_remove_cleanup( > } > > /* > - * Remove a name from a B-tree attribute list. > + * Remove the attribute specified in @args. > * > * 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 in-line 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) > +int > +xfs_attr_remove_iter( > + struct xfs_delattr_context *dac) > { > - struct xfs_da_state *state; > - int retval, error; > - struct xfs_inode *dp = args->dp; > + struct xfs_da_args *args = dac->da_args; > + struct xfs_da_state *state = dac->da_state; > + int retval, error; > + struct xfs_inode *dp = args->dp; > > trace_xfs_attr_node_removename(args); > ... > + case XFS_DAS_CLNUP: > + retval = xfs_attr_node_remove_cleanup(args, state); This is a nit, but when reading the code the "cleanup" name gives the impression that this is a resource cleanup or something along those lines, when this is actually a primary component of the operation where we remove the attr name. That took me a second to find. Could we tweak the state and rename the helper to something like DAS_RMNAME / _node_remove_name() so the naming is a bit more explicit? > > - /* > - * Check to see if the tree needs to be collapsed. > - */ > - if (retval && (state->path.active > 1)) { > - error = xfs_da3_join(state); > - if (error) > - goto out; > - error = xfs_defer_finish(&args->trans); > - if (error) > - goto out; > /* > - * Commit the Btree join operation and start a new trans. > + * Check to see if the tree needs to be collapsed. Set the flag > + * to indicate that the calling function needs to move the > + * shrink operation > */ > - error = xfs_trans_roll_inode(&args->trans, dp); > - if (error) > - goto out; > - } > + if (retval && (state->path.active > 1)) { > + error = xfs_da3_join(state); > + if (error) > + goto out; > > - /* > - * If the result is small enough, push it all into the inode. > - */ > - if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) > - error = xfs_attr_node_shrink(args, state); > + dac->flags |= XFS_DAC_DEFER_FINISH; > + dac->dela_state = XFS_DAS_RM_SHRINK; > + return -EAGAIN; > + } > + > + /* fallthrough */ > + case XFS_DAS_RM_SHRINK: > + /* > + * If the result is small enough, push it all into the inode. > + */ > + if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) > + error = xfs_attr_node_shrink(args, state); > + > + break; > + default: > + ASSERT(0); > + error = -EINVAL; > + goto out; > + } > > + if (error == -EAGAIN) > + return error; > out: > if (state) > xfs_da_state_free(state); ... > diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c > index 48d8e9c..908521e7 100644 > --- a/fs/xfs/libxfs/xfs_attr_remote.c > +++ b/fs/xfs/libxfs/xfs_attr_remote.c ... > @@ -685,31 +687,29 @@ xfs_attr_rmtval_remove( > * Keep de-allocating extents until the remote-value region is gone. > */ > do { > - retval = __xfs_attr_rmtval_remove(args); > - if (retval && retval != -EAGAIN) > - return retval; > + error = __xfs_attr_rmtval_remove(&dac); > + if (error != -EAGAIN) > + break; Shouldn't this retain the (error && error != -EAGAIN) logic to roll the transaction after the final unmap? Even if this is transient, it's probably best to preserve behavior if this is unintentional. Otherwise my only remaining feedback was to add/tweak some comments that I think make the iteration function easier to follow. I've appended a diff for that. If you agree with the changes feel free to just fold them in and/or tweak as necessary. With those various nits and Chandan's feedback addressed, I think this patch looks pretty good. Brian --- 8< --- diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c index 0bea8dd34902..ee885c649c26 100644 --- a/fs/xfs/libxfs/xfs_attr.c +++ b/fs/xfs/libxfs/xfs_attr.c @@ -1289,14 +1289,21 @@ xfs_attr_remove_iter( if (!xfs_inode_hasattr(dp)) return -ENOATTR; + /* + * Shortform or leaf formats don't require transaction rolls and + * thus state transitions. Call the right helper and return. + */ if (dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL) { ASSERT(dp->i_afp->if_flags & XFS_IFINLINE); return xfs_attr_shortform_remove(args); } - if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) return xfs_attr_leaf_removename(args); + /* + * Node format may require transaction rolls. Set up the + * state context and fall into the state machine. + */ if (!dac->da_state) { error = xfs_attr_node_removename_setup(dac); if (error) @@ -1304,7 +1311,7 @@ xfs_attr_remove_iter( state = dac->da_state; } - /* fallthrough */ + /* fallthrough */ case XFS_DAS_RMTBLK: dac->dela_state = XFS_DAS_RMTBLK; @@ -1316,7 +1323,8 @@ xfs_attr_remove_iter( */ if (args->rmtblkno > 0) { /* - * May return -EAGAIN. Remove blocks until 0 is returned + * May return -EAGAIN. Roll and repeat until all remote + * blocks are removed. */ error = __xfs_attr_rmtval_remove(dac); if (error == -EAGAIN) @@ -1325,26 +1333,26 @@ xfs_attr_remove_iter( goto out; /* - * Refill the state structure with buffers, the prior - * calls released our buffers. + * Refill the state structure with buffers (the prior + * calls released our buffers) and close out this + * transaction before proceeding. */ ASSERT(args->rmtblkno == 0); error = xfs_attr_refillstate(state); if (error) goto out; - dac->dela_state = XFS_DAS_CLNUP; dac->flags |= XFS_DAC_DEFER_FINISH; return -EAGAIN; } + /* fallthrough */ case XFS_DAS_CLNUP: retval = xfs_attr_node_remove_cleanup(args, state); /* - * Check to see if the tree needs to be collapsed. Set the flag - * to indicate that the calling function needs to move the - * shrink operation + * Check to see if the tree needs to be collapsed. If so, roll + * the transacton and fall into the shrink state. */ if (retval && (state->path.active > 1)) { error = xfs_da3_join(state); @@ -1360,10 +1368,12 @@ xfs_attr_remove_iter( case XFS_DAS_RM_SHRINK: /* * If the result is small enough, push it all into the inode. + * This is our final state so it's safe to return a dirty + * transaction. */ if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) error = xfs_attr_node_shrink(args, state); - + ASSERT(error != -EAGAIN); break; default: ASSERT(0);
On 4/23/21 10:06 AM, Brian Foster wrote: > On Fri, Apr 16, 2021 at 02:20:44AM -0700, Allison Henderson 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 is merged with >> xfs_attr_node_removename become a new function, xfs_attr_remove_iter. >> This new version uses a sort of state machine like switch to keep track >> of where it was when EAGAIN was returned. A new version of >> xfs_attr_remove_args consists of a simple loop to refresh the >> transaction until the operation is completed. A new XFS_DAC_DEFER_FINISH >> flag is used to finish the transaction where ever the existing code used >> to. >> >> Calls to xfs_attr_rmtval_remove are replaced with the delay ready >> version __xfs_attr_rmtval_remove. We will rename >> __xfs_attr_rmtval_remove back to xfs_attr_rmtval_remove when we are >> done. >> >> xfs_attr_rmtval_remove itself is still in use by the set routines (used >> during a rename). For reasons of preserving existing function, we >> modify xfs_attr_rmtval_remove to call xfs_defer_finish when the flag is >> set. Similar to how xfs_attr_remove_args does here. Once we transition >> the set routines to be delay ready, xfs_attr_rmtval_remove is no longer >> used and will be removed. >> >> 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. See xfs_attr.h for a more >> detailed diagram of the states. >> >> Signed-off-by: Allison Henderson <allison.henderson@oracle.com> >> --- >> fs/xfs/libxfs/xfs_attr.c | 208 +++++++++++++++++++++++++++------------- >> fs/xfs/libxfs/xfs_attr.h | 131 +++++++++++++++++++++++++ >> fs/xfs/libxfs/xfs_attr_leaf.c | 2 +- >> fs/xfs/libxfs/xfs_attr_remote.c | 48 ++++++---- >> fs/xfs/libxfs/xfs_attr_remote.h | 2 +- >> fs/xfs/xfs_attr_inactive.c | 2 +- >> 6 files changed, 305 insertions(+), 88 deletions(-) >> >> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c >> index ed06b60..0bea8dd 100644 >> --- a/fs/xfs/libxfs/xfs_attr.c >> +++ b/fs/xfs/libxfs/xfs_attr.c > ... >> @@ -1231,70 +1262,117 @@ xfs_attr_node_remove_cleanup( >> } >> >> /* >> - * Remove a name from a B-tree attribute list. >> + * Remove the attribute specified in @args. >> * >> * 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 in-line 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) >> +int >> +xfs_attr_remove_iter( >> + struct xfs_delattr_context *dac) >> { >> - struct xfs_da_state *state; >> - int retval, error; >> - struct xfs_inode *dp = args->dp; >> + struct xfs_da_args *args = dac->da_args; >> + struct xfs_da_state *state = dac->da_state; >> + int retval, error; >> + struct xfs_inode *dp = args->dp; >> >> trace_xfs_attr_node_removename(args); >> > ... >> + case XFS_DAS_CLNUP: >> + retval = xfs_attr_node_remove_cleanup(args, state); > > This is a nit, but when reading the code the "cleanup" name gives the > impression that this is a resource cleanup or something along those > lines, when this is actually a primary component of the operation where > we remove the attr name. That took me a second to find. Could we tweak > the state and rename the helper to something like DAS_RMNAME / > _node_remove_name() so the naming is a bit more explicit? Sure, this helper is actually added in patch 2 of this set. I can rename it there? People have already added their rvb's, but I'm assuming people are not bothered by small tweeks like that? That way this patch just sort of moves it and XFS_DAS_CLNUP can turn into XFS_DAS_RMNAME here. > >> >> - /* >> - * Check to see if the tree needs to be collapsed. >> - */ >> - if (retval && (state->path.active > 1)) { >> - error = xfs_da3_join(state); >> - if (error) >> - goto out; >> - error = xfs_defer_finish(&args->trans); >> - if (error) >> - goto out; >> /* >> - * Commit the Btree join operation and start a new trans. >> + * Check to see if the tree needs to be collapsed. Set the flag >> + * to indicate that the calling function needs to move the >> + * shrink operation >> */ >> - error = xfs_trans_roll_inode(&args->trans, dp); >> - if (error) >> - goto out; >> - } >> + if (retval && (state->path.active > 1)) { >> + error = xfs_da3_join(state); >> + if (error) >> + goto out; >> >> - /* >> - * If the result is small enough, push it all into the inode. >> - */ >> - if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) >> - error = xfs_attr_node_shrink(args, state); >> + dac->flags |= XFS_DAC_DEFER_FINISH; >> + dac->dela_state = XFS_DAS_RM_SHRINK; >> + return -EAGAIN; >> + } >> + >> + /* fallthrough */ >> + case XFS_DAS_RM_SHRINK: >> + /* >> + * If the result is small enough, push it all into the inode. >> + */ >> + if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) >> + error = xfs_attr_node_shrink(args, state); >> + >> + break; >> + default: >> + ASSERT(0); >> + error = -EINVAL; >> + goto out; >> + } >> >> + if (error == -EAGAIN) >> + return error; >> out: >> if (state) >> xfs_da_state_free(state); > ... >> diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c >> index 48d8e9c..908521e7 100644 >> --- a/fs/xfs/libxfs/xfs_attr_remote.c >> +++ b/fs/xfs/libxfs/xfs_attr_remote.c > ... >> @@ -685,31 +687,29 @@ xfs_attr_rmtval_remove( >> * Keep de-allocating extents until the remote-value region is gone. >> */ >> do { >> - retval = __xfs_attr_rmtval_remove(args); >> - if (retval && retval != -EAGAIN) >> - return retval; >> + error = __xfs_attr_rmtval_remove(&dac); >> + if (error != -EAGAIN) >> + break; > > Shouldn't this retain the (error && error != -EAGAIN) logic to roll the > transaction after the final unmap? Even if this is transient, it's > probably best to preserve behavior if this is unintentional. Sure, I dont think it's intentional, I think back in v10 we had a different arangement here with a helper inside the while() expression that had equivelent error handling logic. But that got nak'd in the next review and I think I likley forgot to put back this handling. Will fix. > > Otherwise my only remaining feedback was to add/tweak some comments that > I think make the iteration function easier to follow. I've appended a > diff for that. If you agree with the changes feel free to just fold them > in and/or tweak as necessary. With those various nits and Chandan's > feedback addressed, I think this patch looks pretty good. Sure, those all look reasonable. Will add. Thanks for the reviews! Allison > > Brian > > --- 8< --- > > diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c > index 0bea8dd34902..ee885c649c26 100644 > --- a/fs/xfs/libxfs/xfs_attr.c > +++ b/fs/xfs/libxfs/xfs_attr.c > @@ -1289,14 +1289,21 @@ xfs_attr_remove_iter( > if (!xfs_inode_hasattr(dp)) > return -ENOATTR; > > + /* > + * Shortform or leaf formats don't require transaction rolls and > + * thus state transitions. Call the right helper and return. > + */ > if (dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL) { > ASSERT(dp->i_afp->if_flags & XFS_IFINLINE); > return xfs_attr_shortform_remove(args); > } > - > if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) > return xfs_attr_leaf_removename(args); > > + /* > + * Node format may require transaction rolls. Set up the > + * state context and fall into the state machine. > + */ > if (!dac->da_state) { > error = xfs_attr_node_removename_setup(dac); > if (error) > @@ -1304,7 +1311,7 @@ xfs_attr_remove_iter( > state = dac->da_state; > } > > - /* fallthrough */ > + /* fallthrough */ > case XFS_DAS_RMTBLK: > dac->dela_state = XFS_DAS_RMTBLK; > > @@ -1316,7 +1323,8 @@ xfs_attr_remove_iter( > */ > if (args->rmtblkno > 0) { > /* > - * May return -EAGAIN. Remove blocks until 0 is returned > + * May return -EAGAIN. Roll and repeat until all remote > + * blocks are removed. > */ > error = __xfs_attr_rmtval_remove(dac); > if (error == -EAGAIN) > @@ -1325,26 +1333,26 @@ xfs_attr_remove_iter( > goto out; > > /* > - * Refill the state structure with buffers, the prior > - * calls released our buffers. > + * Refill the state structure with buffers (the prior > + * calls released our buffers) and close out this > + * transaction before proceeding. > */ > ASSERT(args->rmtblkno == 0); > error = xfs_attr_refillstate(state); > if (error) > goto out; > - > dac->dela_state = XFS_DAS_CLNUP; > dac->flags |= XFS_DAC_DEFER_FINISH; > return -EAGAIN; > } > > + /* fallthrough */ > case XFS_DAS_CLNUP: > retval = xfs_attr_node_remove_cleanup(args, state); > > /* > - * Check to see if the tree needs to be collapsed. Set the flag > - * to indicate that the calling function needs to move the > - * shrink operation > + * Check to see if the tree needs to be collapsed. If so, roll > + * the transacton and fall into the shrink state. > */ > if (retval && (state->path.active > 1)) { > error = xfs_da3_join(state); > @@ -1360,10 +1368,12 @@ xfs_attr_remove_iter( > case XFS_DAS_RM_SHRINK: > /* > * If the result is small enough, push it all into the inode. > + * This is our final state so it's safe to return a dirty > + * transaction. > */ > if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) > error = xfs_attr_node_shrink(args, state); > - > + ASSERT(error != -EAGAIN); > break; > default: > ASSERT(0); >
On Fri, Apr 23, 2021 at 08:27:28PM -0700, Allison Henderson wrote: > > > On 4/23/21 10:06 AM, Brian Foster wrote: > > On Fri, Apr 16, 2021 at 02:20:44AM -0700, Allison Henderson 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 is merged with > > > xfs_attr_node_removename become a new function, xfs_attr_remove_iter. > > > This new version uses a sort of state machine like switch to keep track > > > of where it was when EAGAIN was returned. A new version of > > > xfs_attr_remove_args consists of a simple loop to refresh the > > > transaction until the operation is completed. A new XFS_DAC_DEFER_FINISH > > > flag is used to finish the transaction where ever the existing code used > > > to. > > > > > > Calls to xfs_attr_rmtval_remove are replaced with the delay ready > > > version __xfs_attr_rmtval_remove. We will rename > > > __xfs_attr_rmtval_remove back to xfs_attr_rmtval_remove when we are > > > done. > > > > > > xfs_attr_rmtval_remove itself is still in use by the set routines (used > > > during a rename). For reasons of preserving existing function, we > > > modify xfs_attr_rmtval_remove to call xfs_defer_finish when the flag is > > > set. Similar to how xfs_attr_remove_args does here. Once we transition > > > the set routines to be delay ready, xfs_attr_rmtval_remove is no longer > > > used and will be removed. > > > > > > 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. See xfs_attr.h for a more > > > detailed diagram of the states. > > > > > > Signed-off-by: Allison Henderson <allison.henderson@oracle.com> > > > --- > > > fs/xfs/libxfs/xfs_attr.c | 208 +++++++++++++++++++++++++++------------- > > > fs/xfs/libxfs/xfs_attr.h | 131 +++++++++++++++++++++++++ > > > fs/xfs/libxfs/xfs_attr_leaf.c | 2 +- > > > fs/xfs/libxfs/xfs_attr_remote.c | 48 ++++++---- > > > fs/xfs/libxfs/xfs_attr_remote.h | 2 +- > > > fs/xfs/xfs_attr_inactive.c | 2 +- > > > 6 files changed, 305 insertions(+), 88 deletions(-) > > > > > > diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c > > > index ed06b60..0bea8dd 100644 > > > --- a/fs/xfs/libxfs/xfs_attr.c > > > +++ b/fs/xfs/libxfs/xfs_attr.c > > ... > > > @@ -1231,70 +1262,117 @@ xfs_attr_node_remove_cleanup( > > > } > > > /* > > > - * Remove a name from a B-tree attribute list. > > > + * Remove the attribute specified in @args. > > > * > > > * 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 in-line 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) > > > +int > > > +xfs_attr_remove_iter( > > > + struct xfs_delattr_context *dac) > > > { > > > - struct xfs_da_state *state; > > > - int retval, error; > > > - struct xfs_inode *dp = args->dp; > > > + struct xfs_da_args *args = dac->da_args; > > > + struct xfs_da_state *state = dac->da_state; > > > + int retval, error; > > > + struct xfs_inode *dp = args->dp; > > > trace_xfs_attr_node_removename(args); > > ... > > > + case XFS_DAS_CLNUP: > > > + retval = xfs_attr_node_remove_cleanup(args, state); > > > > This is a nit, but when reading the code the "cleanup" name gives the > > impression that this is a resource cleanup or something along those > > lines, when this is actually a primary component of the operation where > > we remove the attr name. That took me a second to find. Could we tweak > > the state and rename the helper to something like DAS_RMNAME / > > _node_remove_name() so the naming is a bit more explicit? > Sure, this helper is actually added in patch 2 of this set. I can rename it > there? People have already added their rvb's, but I'm assuming people are > not bothered by small tweeks like that? That way this patch just sort of > moves it and XFS_DAS_CLNUP can turn into XFS_DAS_RMNAME here. <bikeshed> "RMNAME" looks too similar to "RENAME" for my old eyes, can we please pick something else? Like "RM_NAME", or "REMOVE_NAME" ? --D > > > > > > - /* > > > - * Check to see if the tree needs to be collapsed. > > > - */ > > > - if (retval && (state->path.active > 1)) { > > > - error = xfs_da3_join(state); > > > - if (error) > > > - goto out; > > > - error = xfs_defer_finish(&args->trans); > > > - if (error) > > > - goto out; > > > /* > > > - * Commit the Btree join operation and start a new trans. > > > + * Check to see if the tree needs to be collapsed. Set the flag > > > + * to indicate that the calling function needs to move the > > > + * shrink operation > > > */ > > > - error = xfs_trans_roll_inode(&args->trans, dp); > > > - if (error) > > > - goto out; > > > - } > > > + if (retval && (state->path.active > 1)) { > > > + error = xfs_da3_join(state); > > > + if (error) > > > + goto out; > > > - /* > > > - * If the result is small enough, push it all into the inode. > > > - */ > > > - if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) > > > - error = xfs_attr_node_shrink(args, state); > > > + dac->flags |= XFS_DAC_DEFER_FINISH; > > > + dac->dela_state = XFS_DAS_RM_SHRINK; > > > + return -EAGAIN; > > > + } > > > + > > > + /* fallthrough */ > > > + case XFS_DAS_RM_SHRINK: > > > + /* > > > + * If the result is small enough, push it all into the inode. > > > + */ > > > + if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) > > > + error = xfs_attr_node_shrink(args, state); > > > + > > > + break; > > > + default: > > > + ASSERT(0); > > > + error = -EINVAL; > > > + goto out; > > > + } > > > + if (error == -EAGAIN) > > > + return error; > > > out: > > > if (state) > > > xfs_da_state_free(state); > > ... > > > diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c > > > index 48d8e9c..908521e7 100644 > > > --- a/fs/xfs/libxfs/xfs_attr_remote.c > > > +++ b/fs/xfs/libxfs/xfs_attr_remote.c > > ... > > > @@ -685,31 +687,29 @@ xfs_attr_rmtval_remove( > > > * Keep de-allocating extents until the remote-value region is gone. > > > */ > > > do { > > > - retval = __xfs_attr_rmtval_remove(args); > > > - if (retval && retval != -EAGAIN) > > > - return retval; > > > + error = __xfs_attr_rmtval_remove(&dac); > > > + if (error != -EAGAIN) > > > + break; > > > > Shouldn't this retain the (error && error != -EAGAIN) logic to roll the > > transaction after the final unmap? Even if this is transient, it's > > probably best to preserve behavior if this is unintentional. > Sure, I dont think it's intentional, I think back in v10 we had a different > arangement here with a helper inside the while() expression that had > equivelent error handling logic. But that got nak'd in the next review and > I think I likley forgot to put back this handling. Will fix. > > > > > Otherwise my only remaining feedback was to add/tweak some comments that > > I think make the iteration function easier to follow. I've appended a > > diff for that. If you agree with the changes feel free to just fold them > > in and/or tweak as necessary. With those various nits and Chandan's > > feedback addressed, I think this patch looks pretty good. > Sure, those all look reasonable. Will add. Thanks for the reviews! > Allison > > > > > Brian > > > > --- 8< --- > > > > diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c > > index 0bea8dd34902..ee885c649c26 100644 > > --- a/fs/xfs/libxfs/xfs_attr.c > > +++ b/fs/xfs/libxfs/xfs_attr.c > > @@ -1289,14 +1289,21 @@ xfs_attr_remove_iter( > > if (!xfs_inode_hasattr(dp)) > > return -ENOATTR; > > + /* > > + * Shortform or leaf formats don't require transaction rolls and > > + * thus state transitions. Call the right helper and return. > > + */ > > if (dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL) { > > ASSERT(dp->i_afp->if_flags & XFS_IFINLINE); > > return xfs_attr_shortform_remove(args); > > } > > - > > if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) > > return xfs_attr_leaf_removename(args); > > + /* > > + * Node format may require transaction rolls. Set up the > > + * state context and fall into the state machine. > > + */ > > if (!dac->da_state) { > > error = xfs_attr_node_removename_setup(dac); > > if (error) > > @@ -1304,7 +1311,7 @@ xfs_attr_remove_iter( > > state = dac->da_state; > > } > > - /* fallthrough */ > > + /* fallthrough */ > > case XFS_DAS_RMTBLK: > > dac->dela_state = XFS_DAS_RMTBLK; > > @@ -1316,7 +1323,8 @@ xfs_attr_remove_iter( > > */ > > if (args->rmtblkno > 0) { > > /* > > - * May return -EAGAIN. Remove blocks until 0 is returned > > + * May return -EAGAIN. Roll and repeat until all remote > > + * blocks are removed. > > */ > > error = __xfs_attr_rmtval_remove(dac); > > if (error == -EAGAIN) > > @@ -1325,26 +1333,26 @@ xfs_attr_remove_iter( > > goto out; > > /* > > - * Refill the state structure with buffers, the prior > > - * calls released our buffers. > > + * Refill the state structure with buffers (the prior > > + * calls released our buffers) and close out this > > + * transaction before proceeding. > > */ > > ASSERT(args->rmtblkno == 0); > > error = xfs_attr_refillstate(state); > > if (error) > > goto out; > > - > > dac->dela_state = XFS_DAS_CLNUP; > > dac->flags |= XFS_DAC_DEFER_FINISH; > > return -EAGAIN; > > } > > + /* fallthrough */ > > case XFS_DAS_CLNUP: > > retval = xfs_attr_node_remove_cleanup(args, state); > > /* > > - * Check to see if the tree needs to be collapsed. Set the flag > > - * to indicate that the calling function needs to move the > > - * shrink operation > > + * Check to see if the tree needs to be collapsed. If so, roll > > + * the transacton and fall into the shrink state. > > */ > > if (retval && (state->path.active > 1)) { > > error = xfs_da3_join(state); > > @@ -1360,10 +1368,12 @@ xfs_attr_remove_iter( > > case XFS_DAS_RM_SHRINK: > > /* > > * If the result is small enough, push it all into the inode. > > + * This is our final state so it's safe to return a dirty > > + * transaction. > > */ > > if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) > > error = xfs_attr_node_shrink(args, state); > > - > > + ASSERT(error != -EAGAIN); > > break; > > default: > > ASSERT(0); > >
On Sat, Apr 24, 2021 at 08:56:45AM -0700, Darrick J. Wong wrote: > On Fri, Apr 23, 2021 at 08:27:28PM -0700, Allison Henderson wrote: > > > > > > On 4/23/21 10:06 AM, Brian Foster wrote: > > > On Fri, Apr 16, 2021 at 02:20:44AM -0700, Allison Henderson 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 is merged with > > > > xfs_attr_node_removename become a new function, xfs_attr_remove_iter. > > > > This new version uses a sort of state machine like switch to keep track > > > > of where it was when EAGAIN was returned. A new version of > > > > xfs_attr_remove_args consists of a simple loop to refresh the > > > > transaction until the operation is completed. A new XFS_DAC_DEFER_FINISH > > > > flag is used to finish the transaction where ever the existing code used > > > > to. > > > > > > > > Calls to xfs_attr_rmtval_remove are replaced with the delay ready > > > > version __xfs_attr_rmtval_remove. We will rename > > > > __xfs_attr_rmtval_remove back to xfs_attr_rmtval_remove when we are > > > > done. > > > > > > > > xfs_attr_rmtval_remove itself is still in use by the set routines (used > > > > during a rename). For reasons of preserving existing function, we > > > > modify xfs_attr_rmtval_remove to call xfs_defer_finish when the flag is > > > > set. Similar to how xfs_attr_remove_args does here. Once we transition > > > > the set routines to be delay ready, xfs_attr_rmtval_remove is no longer > > > > used and will be removed. > > > > > > > > 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. See xfs_attr.h for a more > > > > detailed diagram of the states. > > > > > > > > Signed-off-by: Allison Henderson <allison.henderson@oracle.com> > > > > --- > > > > fs/xfs/libxfs/xfs_attr.c | 208 +++++++++++++++++++++++++++------------- > > > > fs/xfs/libxfs/xfs_attr.h | 131 +++++++++++++++++++++++++ > > > > fs/xfs/libxfs/xfs_attr_leaf.c | 2 +- > > > > fs/xfs/libxfs/xfs_attr_remote.c | 48 ++++++---- > > > > fs/xfs/libxfs/xfs_attr_remote.h | 2 +- > > > > fs/xfs/xfs_attr_inactive.c | 2 +- > > > > 6 files changed, 305 insertions(+), 88 deletions(-) > > > > > > > > diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c > > > > index ed06b60..0bea8dd 100644 > > > > --- a/fs/xfs/libxfs/xfs_attr.c > > > > +++ b/fs/xfs/libxfs/xfs_attr.c > > > ... > > > > @@ -1231,70 +1262,117 @@ xfs_attr_node_remove_cleanup( > > > > } > > > > /* > > > > - * Remove a name from a B-tree attribute list. > > > > + * Remove the attribute specified in @args. > > > > * > > > > * 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 in-line 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) > > > > +int > > > > +xfs_attr_remove_iter( > > > > + struct xfs_delattr_context *dac) > > > > { > > > > - struct xfs_da_state *state; > > > > - int retval, error; > > > > - struct xfs_inode *dp = args->dp; > > > > + struct xfs_da_args *args = dac->da_args; > > > > + struct xfs_da_state *state = dac->da_state; > > > > + int retval, error; > > > > + struct xfs_inode *dp = args->dp; > > > > trace_xfs_attr_node_removename(args); > > > ... > > > > + case XFS_DAS_CLNUP: > > > > + retval = xfs_attr_node_remove_cleanup(args, state); > > > > > > This is a nit, but when reading the code the "cleanup" name gives the > > > impression that this is a resource cleanup or something along those > > > lines, when this is actually a primary component of the operation where > > > we remove the attr name. That took me a second to find. Could we tweak > > > the state and rename the helper to something like DAS_RMNAME / > > > _node_remove_name() so the naming is a bit more explicit? > > Sure, this helper is actually added in patch 2 of this set. I can rename it > > there? People have already added their rvb's, but I'm assuming people are > > not bothered by small tweeks like that? That way this patch just sort of > > moves it and XFS_DAS_CLNUP can turn into XFS_DAS_RMNAME here. > > <bikeshed> "RMNAME" looks too similar to "RENAME" for my old eyes, can > we please pick something else? Like "RM_NAME", or "REMOVE_NAME" ? > Either of those seem fine to me, FWIW. I think anything that expresses removal of the name/entry over the more generic "cleanup" name is an improvement.. Brian > --D > > > > > > > > > > - /* > > > > - * Check to see if the tree needs to be collapsed. > > > > - */ > > > > - if (retval && (state->path.active > 1)) { > > > > - error = xfs_da3_join(state); > > > > - if (error) > > > > - goto out; > > > > - error = xfs_defer_finish(&args->trans); > > > > - if (error) > > > > - goto out; > > > > /* > > > > - * Commit the Btree join operation and start a new trans. > > > > + * Check to see if the tree needs to be collapsed. Set the flag > > > > + * to indicate that the calling function needs to move the > > > > + * shrink operation > > > > */ > > > > - error = xfs_trans_roll_inode(&args->trans, dp); > > > > - if (error) > > > > - goto out; > > > > - } > > > > + if (retval && (state->path.active > 1)) { > > > > + error = xfs_da3_join(state); > > > > + if (error) > > > > + goto out; > > > > - /* > > > > - * If the result is small enough, push it all into the inode. > > > > - */ > > > > - if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) > > > > - error = xfs_attr_node_shrink(args, state); > > > > + dac->flags |= XFS_DAC_DEFER_FINISH; > > > > + dac->dela_state = XFS_DAS_RM_SHRINK; > > > > + return -EAGAIN; > > > > + } > > > > + > > > > + /* fallthrough */ > > > > + case XFS_DAS_RM_SHRINK: > > > > + /* > > > > + * If the result is small enough, push it all into the inode. > > > > + */ > > > > + if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) > > > > + error = xfs_attr_node_shrink(args, state); > > > > + > > > > + break; > > > > + default: > > > > + ASSERT(0); > > > > + error = -EINVAL; > > > > + goto out; > > > > + } > > > > + if (error == -EAGAIN) > > > > + return error; > > > > out: > > > > if (state) > > > > xfs_da_state_free(state); > > > ... > > > > diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c > > > > index 48d8e9c..908521e7 100644 > > > > --- a/fs/xfs/libxfs/xfs_attr_remote.c > > > > +++ b/fs/xfs/libxfs/xfs_attr_remote.c > > > ... > > > > @@ -685,31 +687,29 @@ xfs_attr_rmtval_remove( > > > > * Keep de-allocating extents until the remote-value region is gone. > > > > */ > > > > do { > > > > - retval = __xfs_attr_rmtval_remove(args); > > > > - if (retval && retval != -EAGAIN) > > > > - return retval; > > > > + error = __xfs_attr_rmtval_remove(&dac); > > > > + if (error != -EAGAIN) > > > > + break; > > > > > > Shouldn't this retain the (error && error != -EAGAIN) logic to roll the > > > transaction after the final unmap? Even if this is transient, it's > > > probably best to preserve behavior if this is unintentional. > > Sure, I dont think it's intentional, I think back in v10 we had a different > > arangement here with a helper inside the while() expression that had > > equivelent error handling logic. But that got nak'd in the next review and > > I think I likley forgot to put back this handling. Will fix. > > > > > > > > Otherwise my only remaining feedback was to add/tweak some comments that > > > I think make the iteration function easier to follow. I've appended a > > > diff for that. If you agree with the changes feel free to just fold them > > > in and/or tweak as necessary. With those various nits and Chandan's > > > feedback addressed, I think this patch looks pretty good. > > Sure, those all look reasonable. Will add. Thanks for the reviews! > > Allison > > > > > > > > Brian > > > > > > --- 8< --- > > > > > > diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c > > > index 0bea8dd34902..ee885c649c26 100644 > > > --- a/fs/xfs/libxfs/xfs_attr.c > > > +++ b/fs/xfs/libxfs/xfs_attr.c > > > @@ -1289,14 +1289,21 @@ xfs_attr_remove_iter( > > > if (!xfs_inode_hasattr(dp)) > > > return -ENOATTR; > > > + /* > > > + * Shortform or leaf formats don't require transaction rolls and > > > + * thus state transitions. Call the right helper and return. > > > + */ > > > if (dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL) { > > > ASSERT(dp->i_afp->if_flags & XFS_IFINLINE); > > > return xfs_attr_shortform_remove(args); > > > } > > > - > > > if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) > > > return xfs_attr_leaf_removename(args); > > > + /* > > > + * Node format may require transaction rolls. Set up the > > > + * state context and fall into the state machine. > > > + */ > > > if (!dac->da_state) { > > > error = xfs_attr_node_removename_setup(dac); > > > if (error) > > > @@ -1304,7 +1311,7 @@ xfs_attr_remove_iter( > > > state = dac->da_state; > > > } > > > - /* fallthrough */ > > > + /* fallthrough */ > > > case XFS_DAS_RMTBLK: > > > dac->dela_state = XFS_DAS_RMTBLK; > > > @@ -1316,7 +1323,8 @@ xfs_attr_remove_iter( > > > */ > > > if (args->rmtblkno > 0) { > > > /* > > > - * May return -EAGAIN. Remove blocks until 0 is returned > > > + * May return -EAGAIN. Roll and repeat until all remote > > > + * blocks are removed. > > > */ > > > error = __xfs_attr_rmtval_remove(dac); > > > if (error == -EAGAIN) > > > @@ -1325,26 +1333,26 @@ xfs_attr_remove_iter( > > > goto out; > > > /* > > > - * Refill the state structure with buffers, the prior > > > - * calls released our buffers. > > > + * Refill the state structure with buffers (the prior > > > + * calls released our buffers) and close out this > > > + * transaction before proceeding. > > > */ > > > ASSERT(args->rmtblkno == 0); > > > error = xfs_attr_refillstate(state); > > > if (error) > > > goto out; > > > - > > > dac->dela_state = XFS_DAS_CLNUP; > > > dac->flags |= XFS_DAC_DEFER_FINISH; > > > return -EAGAIN; > > > } > > > + /* fallthrough */ > > > case XFS_DAS_CLNUP: > > > retval = xfs_attr_node_remove_cleanup(args, state); > > > /* > > > - * Check to see if the tree needs to be collapsed. Set the flag > > > - * to indicate that the calling function needs to move the > > > - * shrink operation > > > + * Check to see if the tree needs to be collapsed. If so, roll > > > + * the transacton and fall into the shrink state. > > > */ > > > if (retval && (state->path.active > 1)) { > > > error = xfs_da3_join(state); > > > @@ -1360,10 +1368,12 @@ xfs_attr_remove_iter( > > > case XFS_DAS_RM_SHRINK: > > > /* > > > * If the result is small enough, push it all into the inode. > > > + * This is our final state so it's safe to return a dirty > > > + * transaction. > > > */ > > > if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) > > > error = xfs_attr_node_shrink(args, state); > > > - > > > + ASSERT(error != -EAGAIN); > > > break; > > > default: > > > ASSERT(0); > > > >
On 4/26/21 4:49 AM, Brian Foster wrote: > On Sat, Apr 24, 2021 at 08:56:45AM -0700, Darrick J. Wong wrote: >> On Fri, Apr 23, 2021 at 08:27:28PM -0700, Allison Henderson wrote: >>> >>> >>> On 4/23/21 10:06 AM, Brian Foster wrote: >>>> On Fri, Apr 16, 2021 at 02:20:44AM -0700, Allison Henderson 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 is merged with >>>>> xfs_attr_node_removename become a new function, xfs_attr_remove_iter. >>>>> This new version uses a sort of state machine like switch to keep track >>>>> of where it was when EAGAIN was returned. A new version of >>>>> xfs_attr_remove_args consists of a simple loop to refresh the >>>>> transaction until the operation is completed. A new XFS_DAC_DEFER_FINISH >>>>> flag is used to finish the transaction where ever the existing code used >>>>> to. >>>>> >>>>> Calls to xfs_attr_rmtval_remove are replaced with the delay ready >>>>> version __xfs_attr_rmtval_remove. We will rename >>>>> __xfs_attr_rmtval_remove back to xfs_attr_rmtval_remove when we are >>>>> done. >>>>> >>>>> xfs_attr_rmtval_remove itself is still in use by the set routines (used >>>>> during a rename). For reasons of preserving existing function, we >>>>> modify xfs_attr_rmtval_remove to call xfs_defer_finish when the flag is >>>>> set. Similar to how xfs_attr_remove_args does here. Once we transition >>>>> the set routines to be delay ready, xfs_attr_rmtval_remove is no longer >>>>> used and will be removed. >>>>> >>>>> 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. See xfs_attr.h for a more >>>>> detailed diagram of the states. >>>>> >>>>> Signed-off-by: Allison Henderson <allison.henderson@oracle.com> >>>>> --- >>>>> fs/xfs/libxfs/xfs_attr.c | 208 +++++++++++++++++++++++++++------------- >>>>> fs/xfs/libxfs/xfs_attr.h | 131 +++++++++++++++++++++++++ >>>>> fs/xfs/libxfs/xfs_attr_leaf.c | 2 +- >>>>> fs/xfs/libxfs/xfs_attr_remote.c | 48 ++++++---- >>>>> fs/xfs/libxfs/xfs_attr_remote.h | 2 +- >>>>> fs/xfs/xfs_attr_inactive.c | 2 +- >>>>> 6 files changed, 305 insertions(+), 88 deletions(-) >>>>> >>>>> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c >>>>> index ed06b60..0bea8dd 100644 >>>>> --- a/fs/xfs/libxfs/xfs_attr.c >>>>> +++ b/fs/xfs/libxfs/xfs_attr.c >>>> ... >>>>> @@ -1231,70 +1262,117 @@ xfs_attr_node_remove_cleanup( >>>>> } >>>>> /* >>>>> - * Remove a name from a B-tree attribute list. >>>>> + * Remove the attribute specified in @args. >>>>> * >>>>> * 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 in-line 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) >>>>> +int >>>>> +xfs_attr_remove_iter( >>>>> + struct xfs_delattr_context *dac) >>>>> { >>>>> - struct xfs_da_state *state; >>>>> - int retval, error; >>>>> - struct xfs_inode *dp = args->dp; >>>>> + struct xfs_da_args *args = dac->da_args; >>>>> + struct xfs_da_state *state = dac->da_state; >>>>> + int retval, error; >>>>> + struct xfs_inode *dp = args->dp; >>>>> trace_xfs_attr_node_removename(args); >>>> ... >>>>> + case XFS_DAS_CLNUP: >>>>> + retval = xfs_attr_node_remove_cleanup(args, state); >>>> >>>> This is a nit, but when reading the code the "cleanup" name gives the >>>> impression that this is a resource cleanup or something along those >>>> lines, when this is actually a primary component of the operation where >>>> we remove the attr name. That took me a second to find. Could we tweak >>>> the state and rename the helper to something like DAS_RMNAME / >>>> _node_remove_name() so the naming is a bit more explicit? >>> Sure, this helper is actually added in patch 2 of this set. I can rename it >>> there? People have already added their rvb's, but I'm assuming people are >>> not bothered by small tweeks like that? That way this patch just sort of >>> moves it and XFS_DAS_CLNUP can turn into XFS_DAS_RMNAME here. >> >> <bikeshed> "RMNAME" looks too similar to "RENAME" for my old eyes, can >> we please pick something else? Like "RM_NAME", or "REMOVE_NAME" ? >> > > Either of those seem fine to me, FWIW. I think anything that expresses > removal of the name/entry over the more generic "cleanup" name is an > improvement.. > > Brian Alrighty, lets go with RM_NAME then. Will update. Thanks for the feedback. Allison > >> --D >> >>> >>>> >>>>> - /* >>>>> - * Check to see if the tree needs to be collapsed. >>>>> - */ >>>>> - if (retval && (state->path.active > 1)) { >>>>> - error = xfs_da3_join(state); >>>>> - if (error) >>>>> - goto out; >>>>> - error = xfs_defer_finish(&args->trans); >>>>> - if (error) >>>>> - goto out; >>>>> /* >>>>> - * Commit the Btree join operation and start a new trans. >>>>> + * Check to see if the tree needs to be collapsed. Set the flag >>>>> + * to indicate that the calling function needs to move the >>>>> + * shrink operation >>>>> */ >>>>> - error = xfs_trans_roll_inode(&args->trans, dp); >>>>> - if (error) >>>>> - goto out; >>>>> - } >>>>> + if (retval && (state->path.active > 1)) { >>>>> + error = xfs_da3_join(state); >>>>> + if (error) >>>>> + goto out; >>>>> - /* >>>>> - * If the result is small enough, push it all into the inode. >>>>> - */ >>>>> - if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) >>>>> - error = xfs_attr_node_shrink(args, state); >>>>> + dac->flags |= XFS_DAC_DEFER_FINISH; >>>>> + dac->dela_state = XFS_DAS_RM_SHRINK; >>>>> + return -EAGAIN; >>>>> + } >>>>> + >>>>> + /* fallthrough */ >>>>> + case XFS_DAS_RM_SHRINK: >>>>> + /* >>>>> + * If the result is small enough, push it all into the inode. >>>>> + */ >>>>> + if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) >>>>> + error = xfs_attr_node_shrink(args, state); >>>>> + >>>>> + break; >>>>> + default: >>>>> + ASSERT(0); >>>>> + error = -EINVAL; >>>>> + goto out; >>>>> + } >>>>> + if (error == -EAGAIN) >>>>> + return error; >>>>> out: >>>>> if (state) >>>>> xfs_da_state_free(state); >>>> ... >>>>> diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c >>>>> index 48d8e9c..908521e7 100644 >>>>> --- a/fs/xfs/libxfs/xfs_attr_remote.c >>>>> +++ b/fs/xfs/libxfs/xfs_attr_remote.c >>>> ... >>>>> @@ -685,31 +687,29 @@ xfs_attr_rmtval_remove( >>>>> * Keep de-allocating extents until the remote-value region is gone. >>>>> */ >>>>> do { >>>>> - retval = __xfs_attr_rmtval_remove(args); >>>>> - if (retval && retval != -EAGAIN) >>>>> - return retval; >>>>> + error = __xfs_attr_rmtval_remove(&dac); >>>>> + if (error != -EAGAIN) >>>>> + break; >>>> >>>> Shouldn't this retain the (error && error != -EAGAIN) logic to roll the >>>> transaction after the final unmap? Even if this is transient, it's >>>> probably best to preserve behavior if this is unintentional. >>> Sure, I dont think it's intentional, I think back in v10 we had a different >>> arangement here with a helper inside the while() expression that had >>> equivelent error handling logic. But that got nak'd in the next review and >>> I think I likley forgot to put back this handling. Will fix. >>> >>>> >>>> Otherwise my only remaining feedback was to add/tweak some comments that >>>> I think make the iteration function easier to follow. I've appended a >>>> diff for that. If you agree with the changes feel free to just fold them >>>> in and/or tweak as necessary. With those various nits and Chandan's >>>> feedback addressed, I think this patch looks pretty good. >>> Sure, those all look reasonable. Will add. Thanks for the reviews! >>> Allison >>> >>>> >>>> Brian >>>> >>>> --- 8< --- >>>> >>>> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c >>>> index 0bea8dd34902..ee885c649c26 100644 >>>> --- a/fs/xfs/libxfs/xfs_attr.c >>>> +++ b/fs/xfs/libxfs/xfs_attr.c >>>> @@ -1289,14 +1289,21 @@ xfs_attr_remove_iter( >>>> if (!xfs_inode_hasattr(dp)) >>>> return -ENOATTR; >>>> + /* >>>> + * Shortform or leaf formats don't require transaction rolls and >>>> + * thus state transitions. Call the right helper and return. >>>> + */ >>>> if (dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL) { >>>> ASSERT(dp->i_afp->if_flags & XFS_IFINLINE); >>>> return xfs_attr_shortform_remove(args); >>>> } >>>> - >>>> if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) >>>> return xfs_attr_leaf_removename(args); >>>> + /* >>>> + * Node format may require transaction rolls. Set up the >>>> + * state context and fall into the state machine. >>>> + */ >>>> if (!dac->da_state) { >>>> error = xfs_attr_node_removename_setup(dac); >>>> if (error) >>>> @@ -1304,7 +1311,7 @@ xfs_attr_remove_iter( >>>> state = dac->da_state; >>>> } >>>> - /* fallthrough */ >>>> + /* fallthrough */ >>>> case XFS_DAS_RMTBLK: >>>> dac->dela_state = XFS_DAS_RMTBLK; >>>> @@ -1316,7 +1323,8 @@ xfs_attr_remove_iter( >>>> */ >>>> if (args->rmtblkno > 0) { >>>> /* >>>> - * May return -EAGAIN. Remove blocks until 0 is returned >>>> + * May return -EAGAIN. Roll and repeat until all remote >>>> + * blocks are removed. >>>> */ >>>> error = __xfs_attr_rmtval_remove(dac); >>>> if (error == -EAGAIN) >>>> @@ -1325,26 +1333,26 @@ xfs_attr_remove_iter( >>>> goto out; >>>> /* >>>> - * Refill the state structure with buffers, the prior >>>> - * calls released our buffers. >>>> + * Refill the state structure with buffers (the prior >>>> + * calls released our buffers) and close out this >>>> + * transaction before proceeding. >>>> */ >>>> ASSERT(args->rmtblkno == 0); >>>> error = xfs_attr_refillstate(state); >>>> if (error) >>>> goto out; >>>> - >>>> dac->dela_state = XFS_DAS_CLNUP; >>>> dac->flags |= XFS_DAC_DEFER_FINISH; >>>> return -EAGAIN; >>>> } >>>> + /* fallthrough */ >>>> case XFS_DAS_CLNUP: >>>> retval = xfs_attr_node_remove_cleanup(args, state); >>>> /* >>>> - * Check to see if the tree needs to be collapsed. Set the flag >>>> - * to indicate that the calling function needs to move the >>>> - * shrink operation >>>> + * Check to see if the tree needs to be collapsed. If so, roll >>>> + * the transacton and fall into the shrink state. >>>> */ >>>> if (retval && (state->path.active > 1)) { >>>> error = xfs_da3_join(state); >>>> @@ -1360,10 +1368,12 @@ xfs_attr_remove_iter( >>>> case XFS_DAS_RM_SHRINK: >>>> /* >>>> * If the result is small enough, push it all into the inode. >>>> + * This is our final state so it's safe to return a dirty >>>> + * transaction. >>>> */ >>>> if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) >>>> error = xfs_attr_node_shrink(args, state); >>>> - >>>> + ASSERT(error != -EAGAIN); >>>> break; >>>> default: >>>> ASSERT(0); >>>> >> >
diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c index ed06b60..0bea8dd 100644 --- a/fs/xfs/libxfs/xfs_attr.c +++ b/fs/xfs/libxfs/xfs_attr.c @@ -57,7 +57,6 @@ STATIC int xfs_attr_node_addname(struct xfs_da_args *args, struct xfs_da_state *state); STATIC int xfs_attr_node_addname_find_attr(struct xfs_da_args *args, struct xfs_da_state **state); -STATIC int xfs_attr_node_removename(xfs_da_args_t *args); STATIC int xfs_attr_node_addname_clear_incomplete(struct xfs_da_args *args); STATIC int xfs_attr_node_hasname(xfs_da_args_t *args, struct xfs_da_state **state); @@ -221,6 +220,31 @@ xfs_attr_is_shortform( ip->i_afp->if_nextents == 0); } +/* + * Checks to see if a delayed attribute transaction should be rolled. If so, + * transaction is finished or rolled as needed. + */ +int +xfs_attr_trans_roll( + struct xfs_delattr_context *dac) +{ + struct xfs_da_args *args = dac->da_args; + int error; + + if (dac->flags & XFS_DAC_DEFER_FINISH) { + /* + * The caller wants us to finish all the deferred ops so that we + * avoid pinning the log tail with a large number of deferred + * ops. + */ + dac->flags &= ~XFS_DAC_DEFER_FINISH; + error = xfs_defer_finish(&args->trans); + } else + error = xfs_trans_roll_inode(&args->trans, args->dp); + + return error; +} + STATIC int xfs_attr_set_fmt( struct xfs_da_args *args) @@ -527,21 +551,23 @@ xfs_has_attr( */ int xfs_attr_remove_args( - struct xfs_da_args *args) + struct xfs_da_args *args) { - struct xfs_inode *dp = args->dp; - int error; + int error; + struct xfs_delattr_context dac = { + .da_args = args, + }; - if (!xfs_inode_hasattr(dp)) { - error = -ENOATTR; - } else if (dp->i_afp->if_format == 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); - } else { - error = xfs_attr_node_removename(args); - } + do { + error = xfs_attr_remove_iter(&dac); + if (error != -EAGAIN) + break; + + error = xfs_attr_trans_roll(&dac); + if (error) + return error; + + } while (true); return error; } @@ -1187,14 +1213,16 @@ xfs_attr_leaf_mark_incomplete( */ STATIC int xfs_attr_node_removename_setup( - struct xfs_da_args *args, - struct xfs_da_state **state) + struct xfs_delattr_context *dac) { - int error; + struct xfs_da_args *args = dac->da_args; + struct xfs_da_state **state = &dac->da_state; + int error; error = xfs_attr_node_hasname(args, state); if (error != -EEXIST) return error; + error = 0; ASSERT((*state)->path.blk[(*state)->path.active - 1].bp != NULL); ASSERT((*state)->path.blk[(*state)->path.active - 1].magic == @@ -1203,10 +1231,13 @@ int xfs_attr_node_removename_setup( if (args->rmtblkno > 0) { error = xfs_attr_leaf_mark_incomplete(args, *state); if (error) - return error; + goto out; - return xfs_attr_rmtval_invalidate(args); + error = xfs_attr_rmtval_invalidate(args); } +out: + if (error) + xfs_da_state_free(*state); return 0; } @@ -1231,70 +1262,117 @@ xfs_attr_node_remove_cleanup( } /* - * Remove a name from a B-tree attribute list. + * Remove the attribute specified in @args. * * 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 in-line 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) +int +xfs_attr_remove_iter( + struct xfs_delattr_context *dac) { - struct xfs_da_state *state; - int retval, error; - struct xfs_inode *dp = args->dp; + struct xfs_da_args *args = dac->da_args; + struct xfs_da_state *state = dac->da_state; + int retval, error; + struct xfs_inode *dp = args->dp; trace_xfs_attr_node_removename(args); - error = xfs_attr_node_removename_setup(args, &state); - if (error) - goto out; + switch (dac->dela_state) { + case XFS_DAS_UNINIT: + if (!xfs_inode_hasattr(dp)) + return -ENOATTR; - /* - * If there is an out-of-line value, de-allocate the blocks. - * 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. - */ - if (args->rmtblkno > 0) { - error = xfs_attr_rmtval_remove(args); - if (error) - goto out; + if (dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL) { + ASSERT(dp->i_afp->if_flags & XFS_IFINLINE); + return xfs_attr_shortform_remove(args); + } + + if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) + return xfs_attr_leaf_removename(args); + + if (!dac->da_state) { + error = xfs_attr_node_removename_setup(dac); + if (error) + return error; + state = dac->da_state; + } + + /* fallthrough */ + case XFS_DAS_RMTBLK: + dac->dela_state = XFS_DAS_RMTBLK; /* - * Refill the state structure with buffers, the prior calls - * released our buffers. + * If there is an out-of-line value, de-allocate the blocks. + * 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. */ - error = xfs_attr_refillstate(state); - if (error) - goto out; - } - retval = xfs_attr_node_remove_cleanup(args, state); + if (args->rmtblkno > 0) { + /* + * May return -EAGAIN. Remove blocks until 0 is returned + */ + error = __xfs_attr_rmtval_remove(dac); + if (error == -EAGAIN) + return error; + else if (error) + goto out; + + /* + * Refill the state structure with buffers, the prior + * calls released our buffers. + */ + ASSERT(args->rmtblkno == 0); + error = xfs_attr_refillstate(state); + if (error) + goto out; + + dac->dela_state = XFS_DAS_CLNUP; + dac->flags |= XFS_DAC_DEFER_FINISH; + return -EAGAIN; + } + + case XFS_DAS_CLNUP: + retval = xfs_attr_node_remove_cleanup(args, state); - /* - * Check to see if the tree needs to be collapsed. - */ - if (retval && (state->path.active > 1)) { - error = xfs_da3_join(state); - if (error) - goto out; - error = xfs_defer_finish(&args->trans); - if (error) - goto out; /* - * Commit the Btree join operation and start a new trans. + * Check to see if the tree needs to be collapsed. Set the flag + * to indicate that the calling function needs to move the + * shrink operation */ - error = xfs_trans_roll_inode(&args->trans, dp); - if (error) - goto out; - } + if (retval && (state->path.active > 1)) { + error = xfs_da3_join(state); + if (error) + goto out; - /* - * If the result is small enough, push it all into the inode. - */ - if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) - error = xfs_attr_node_shrink(args, state); + dac->flags |= XFS_DAC_DEFER_FINISH; + dac->dela_state = XFS_DAS_RM_SHRINK; + return -EAGAIN; + } + + /* fallthrough */ + case XFS_DAS_RM_SHRINK: + /* + * If the result is small enough, push it all into the inode. + */ + if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) + error = xfs_attr_node_shrink(args, state); + + break; + default: + ASSERT(0); + error = -EINVAL; + goto out; + } + if (error == -EAGAIN) + return error; out: if (state) xfs_da_state_free(state); diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h index 3e97a93..28fe719 100644 --- a/fs/xfs/libxfs/xfs_attr.h +++ b/fs/xfs/libxfs/xfs_attr.h @@ -74,6 +74,133 @@ struct xfs_attr_list_context { }; +/* + * ======================================================================== + * Structure used to pass context around among the delayed routines. + * ======================================================================== + */ + +/* + * 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() + * │ + * v + * have attr to remove? ──n──> done + * │ + * y + * │ + * v + * are we short form? ──y──> xfs_attr_shortform_remove ──> done + * │ + * n + * │ + * V + * are we leaf form? ──y──> xfs_attr_leaf_removename ──> done + * │ + * n + * │ + * V + * ┌── need to setup state? + * │ │ + * n y + * │ │ + * │ v + * │ find attr and get state + * │ attr has blks? ───n────┐ + * │ │ v + * │ │ find and invalidate + * │ y the blocks. mark + * │ │ attr incomplete + * │ ├────────────────┘ + * └──────────┤ + * │ + * v + * Have blks to remove? ───y─────────┐ + * │ ^ remove the blks + * │ │ │ + * │ │ v + * │ XFS_DAS_RMTBLK <─n── done? + * │ re-enter with │ + * │ one less blk to y + * │ remove │ + * │ V + * │ refill the state + * n │ + * │ v + * │ XFS_DAS_CLNUP + * │ │ + * ├─────────────────────────┘ + * │ + * v + * remove leaf and + * update hash with + * xfs_attr_node_remove_cleanup + * │ + * v + * need to + * shrink tree? ─n─┐ + * │ │ + * y │ + * │ │ + * v │ + * join leaf │ + * │ │ + * v │ + * XFS_DAS_RM_SHRINK │ + * │ │ + * v │ + * do the shrink │ + * │ │ + * v │ + * free state <──┘ + * │ + * v + * done + * + */ + +/* + * Enum values for xfs_delattr_context.da_state + * + * These values are used by delayed attribute operations to keep track of where + * they were before they returned -EAGAIN. A return code of -EAGAIN signals the + * calling function to roll the transaction, and then recall the subroutine to + * finish the operation. The enum is then used by the subroutine to jump back + * to where it was and resume executing where it left off. + */ +enum xfs_delattr_state { + XFS_DAS_UNINIT = 0, /* No state has been set yet */ + XFS_DAS_RMTBLK, /* Removing remote blks */ + XFS_DAS_CLNUP, /* Clean up phase */ + XFS_DAS_RM_SHRINK, /* We are shrinking the tree */ +}; + +/* + * Defines for xfs_delattr_context.flags + */ +#define XFS_DAC_DEFER_FINISH 0x01 /* finish the transaction */ + +/* + * Context used for keeping track of delayed attribute operations + */ +struct xfs_delattr_context { + struct xfs_da_args *da_args; + + /* Used in xfs_attr_node_removename to roll through removing blocks */ + struct xfs_da_state *da_state; + + /* Used to keep track of current state of delayed operation */ + unsigned int flags; + enum xfs_delattr_state dela_state; +}; + /*======================================================================== * Function prototypes for the kernel. *========================================================================*/ @@ -91,6 +218,10 @@ int xfs_attr_set(struct xfs_da_args *args); int xfs_attr_set_args(struct xfs_da_args *args); int xfs_has_attr(struct xfs_da_args *args); int xfs_attr_remove_args(struct xfs_da_args *args); +int xfs_attr_remove_iter(struct xfs_delattr_context *dac); +int xfs_attr_trans_roll(struct xfs_delattr_context *dac); bool xfs_attr_namecheck(const void *name, size_t length); +void xfs_delattr_context_init(struct xfs_delattr_context *dac, + struct xfs_da_args *args); #endif /* __XFS_ATTR_H__ */ diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c index 23e2bf3..ea019e0 100644 --- a/fs/xfs/libxfs/xfs_attr_leaf.c +++ b/fs/xfs/libxfs/xfs_attr_leaf.c @@ -19,8 +19,8 @@ #include "xfs_bmap_btree.h" #include "xfs_bmap.h" #include "xfs_attr_sf.h" -#include "xfs_attr_remote.h" #include "xfs_attr.h" +#include "xfs_attr_remote.h" #include "xfs_attr_leaf.h" #include "xfs_error.h" #include "xfs_trace.h" diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c index 48d8e9c..908521e7 100644 --- a/fs/xfs/libxfs/xfs_attr_remote.c +++ b/fs/xfs/libxfs/xfs_attr_remote.c @@ -674,10 +674,12 @@ xfs_attr_rmtval_invalidate( */ int xfs_attr_rmtval_remove( - struct xfs_da_args *args) + struct xfs_da_args *args) { - int error; - int retval; + int error; + struct xfs_delattr_context dac = { + .da_args = args, + }; trace_xfs_attr_rmtval_remove(args); @@ -685,31 +687,29 @@ xfs_attr_rmtval_remove( * Keep de-allocating extents until the remote-value region is gone. */ do { - retval = __xfs_attr_rmtval_remove(args); - if (retval && retval != -EAGAIN) - return retval; + error = __xfs_attr_rmtval_remove(&dac); + if (error != -EAGAIN) + break; - /* - * Close out trans and start the next one in the chain. - */ - error = xfs_trans_roll_inode(&args->trans, args->dp); + error = xfs_attr_trans_roll(&dac); if (error) return error; - } while (retval == -EAGAIN); + } while (true); - return 0; + return error; } /* * Remove the value associated with an attribute by deleting the out-of-line - * buffer that it is stored on. Returns EAGAIN for the caller to refresh the + * buffer that it is stored on. Returns -EAGAIN for the caller to refresh the * transaction and re-call the function */ int __xfs_attr_rmtval_remove( - struct xfs_da_args *args) + struct xfs_delattr_context *dac) { - int error, done; + struct xfs_da_args *args = dac->da_args; + int error, done; /* * Unmap value blocks for this attr. @@ -719,12 +719,20 @@ __xfs_attr_rmtval_remove( if (error) return error; - error = xfs_defer_finish(&args->trans); - if (error) - return error; - - if (!done) + /* + * We don't need an explicit state here to pick up where we left off. We + * can figure it out using the !done return code. Calling function only + * needs to keep recalling this routine until we indicate to stop by + * returning anything other than -EAGAIN. The actual value of + * attr->xattri_dela_state may be some value reminiscent of the calling + * function, but it's value is irrelevant with in the context of this + * function. Once we are done here, the next state is set as needed + * by the parent + */ + if (!done) { + dac->flags |= XFS_DAC_DEFER_FINISH; return -EAGAIN; + } return error; } diff --git a/fs/xfs/libxfs/xfs_attr_remote.h b/fs/xfs/libxfs/xfs_attr_remote.h index 9eee615..002fd30 100644 --- a/fs/xfs/libxfs/xfs_attr_remote.h +++ b/fs/xfs/libxfs/xfs_attr_remote.h @@ -14,5 +14,5 @@ int xfs_attr_rmtval_remove(struct xfs_da_args *args); int xfs_attr_rmtval_stale(struct xfs_inode *ip, struct xfs_bmbt_irec *map, xfs_buf_flags_t incore_flags); int xfs_attr_rmtval_invalidate(struct xfs_da_args *args); -int __xfs_attr_rmtval_remove(struct xfs_da_args *args); +int __xfs_attr_rmtval_remove(struct xfs_delattr_context *dac); #endif /* __XFS_ATTR_REMOTE_H__ */ diff --git a/fs/xfs/xfs_attr_inactive.c b/fs/xfs/xfs_attr_inactive.c index bfad669..aaa7e66 100644 --- a/fs/xfs/xfs_attr_inactive.c +++ b/fs/xfs/xfs_attr_inactive.c @@ -15,10 +15,10 @@ #include "xfs_da_format.h" #include "xfs_da_btree.h" #include "xfs_inode.h" +#include "xfs_attr.h" #include "xfs_attr_remote.h" #include "xfs_trans.h" #include "xfs_bmap.h" -#include "xfs_attr.h" #include "xfs_attr_leaf.h" #include "xfs_quota.h" #include "xfs_dir2.h"
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 is merged with xfs_attr_node_removename become a new function, xfs_attr_remove_iter. This new version uses a sort of state machine like switch to keep track of where it was when EAGAIN was returned. A new version of xfs_attr_remove_args consists of a simple loop to refresh the transaction until the operation is completed. A new XFS_DAC_DEFER_FINISH flag is used to finish the transaction where ever the existing code used to. Calls to xfs_attr_rmtval_remove are replaced with the delay ready version __xfs_attr_rmtval_remove. We will rename __xfs_attr_rmtval_remove back to xfs_attr_rmtval_remove when we are done. xfs_attr_rmtval_remove itself is still in use by the set routines (used during a rename). For reasons of preserving existing function, we modify xfs_attr_rmtval_remove to call xfs_defer_finish when the flag is set. Similar to how xfs_attr_remove_args does here. Once we transition the set routines to be delay ready, xfs_attr_rmtval_remove is no longer used and will be removed. 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. See xfs_attr.h for a more detailed diagram of the states. Signed-off-by: Allison Henderson <allison.henderson@oracle.com> --- fs/xfs/libxfs/xfs_attr.c | 208 +++++++++++++++++++++++++++------------- fs/xfs/libxfs/xfs_attr.h | 131 +++++++++++++++++++++++++ fs/xfs/libxfs/xfs_attr_leaf.c | 2 +- fs/xfs/libxfs/xfs_attr_remote.c | 48 ++++++---- fs/xfs/libxfs/xfs_attr_remote.h | 2 +- fs/xfs/xfs_attr_inactive.c | 2 +- 6 files changed, 305 insertions(+), 88 deletions(-)