This patch adds new delayed attribute routines:
xfs_attr_set_later
xfs_attr_remove_later
xfs_leaf_addname_later
xfs_node_addname_later
xfs_node_removename_later
These routines are similar to their existing counter parts,
but they do not roll or commit transactions. They instead
return -EAGAIN to allow the calling function to roll the
transaction and recall the function. This allows the
attribute operations to be logged in multiple smaller
transactions.
Signed-off-by: Allison Collins <allison.henderson@xxxxxxxxxx>
---
libxfs/xfs_attr.c | 592 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
libxfs/xfs_attr.h | 2 +
2 files changed, 593 insertions(+), 1 deletion(-)
diff --git a/libxfs/xfs_attr.c b/libxfs/xfs_attr.c
index 3f354c8..e4d1c0c 100644
--- a/libxfs/xfs_attr.c
+++ b/libxfs/xfs_attr.c
@@ -44,6 +44,7 @@ STATIC int xfs_attr_shortform_addname(xfs_da_args_t *args);
*/
STATIC int xfs_attr_leaf_get(xfs_da_args_t *args);
STATIC int xfs_attr_leaf_addname(xfs_da_args_t *args);
+STATIC int xfs_leaf_addname_later(xfs_da_args_t *args);
STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args);
STATIC int xfs_leaf_has_attr(struct xfs_da_args *args, struct xfs_buf **bp);
@@ -52,12 +53,14 @@ STATIC int xfs_leaf_has_attr(struct xfs_da_args *args, struct xfs_buf **bp);
*/
STATIC int xfs_attr_node_get(xfs_da_args_t *args);
STATIC int xfs_attr_node_addname(xfs_da_args_t *args);
+STATIC int xfs_node_addname_later(xfs_da_args_t *args);
STATIC int xfs_attr_node_removename(xfs_da_args_t *args);
+STATIC int xfs_node_removename_later(xfs_da_args_t *args);
STATIC int xfs_attr_node_hasname(xfs_da_args_t *args,
struct xfs_da_state **state);
STATIC int xfs_attr_fillstate(xfs_da_state_t *state);
STATIC int xfs_attr_refillstate(xfs_da_state_t *state);
-
+STATIC int xfs_attr_leaf_try_add(struct xfs_da_args *args, struct xfs_buf *bp);
STATIC int
xfs_attr_args_init(
@@ -279,6 +282,112 @@ xfs_attr_set_args(
}
/*
+ * Set the attribute specified in @args.
+ * This routine is meant to function as a delayed operation, and may return
+ * -EGAIN 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.
+ */
+int
+xfs_attr_set_later(
+ struct xfs_da_args *args,
+ struct xfs_buf **leaf_bp)
+{
+ struct xfs_inode *dp = args->dp;
+ int error = 0;
+ int sf_size;
+
+ /*
+ * New inodes may not have an attribute fork yet. So set the attribute
+ * fork appropriately
+ */
+ if (XFS_IFORK_Q((args->dp)) == 0) {
+ sf_size = sizeof(struct xfs_attr_sf_hdr) +
+ XFS_ATTR_SF_ENTSIZE_BYNAME(args->name.len, args->valuelen);
+ xfs_bmap_set_attrforkoff(args->dp, sf_size, NULL);
+ args->dp->i_afp = kmem_zone_zalloc(xfs_ifork_zone, 0);
+ args->dp->i_afp->if_flags = XFS_IFEXTENTS;
+ }
+
+ /*
+ * If the attribute list is non-existent or a shortform list,
+ * upgrade it to a single-leaf-block attribute list.
+ */
+ if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL ||
+ (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
+ dp->i_d.di_anextents == 0)) {
+ /*
+ * Build initial attribute list (if required).
+ */
+ if (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS)
+ xfs_attr_shortform_create(args);
+
+ /*
+ * Try to add the attr to the attribute list in the inode.
+ */
+ error = xfs_attr_try_sf_addname(dp, args);
+ if (error != -ENOSPC)
+ return error;
+
+ /*
+ * It won't fit in the shortform, transform to a leaf block.
+ * GROT: another possible req'mt for a double-split btree op.
+ */
+ error = xfs_attr_shortform_to_leaf(args, leaf_bp);
+ if (error)
+ return error;
+
+ /*
+ * Prevent the leaf buffer from being unlocked so that a
+ * concurrent AIL push cannot grab the half-baked leaf
+ * buffer and run into problems with the write verifier.
+ */
+
+ xfs_trans_bhold(args->trans, *leaf_bp);
+ return -EAGAIN;
+ }
+
+ /*
+ * After a shortform to leaf conversion, we need to hold the leaf and
+ * cylce out the transaction. When we get back, we need to release
+ * the leaf.
+ */
+ if (*leaf_bp != NULL) {
+ xfs_trans_bhold_release(args->trans, *leaf_bp);
+ *leaf_bp = NULL;
+ }
+
+ /*
+ * If we fit in a block, or we are in the middle of adding a leaf name.
+ * xfs_attr_da_leaf_addname will set the XFS_DC_ALLOC_LEAF to indicate
+ * that it is not done yet, and need to be recalled to finish up from
+ * the last EAGAIN it returned
+ */
+ if (xfs_bmap_one_block(dp, XFS_ATTR_FORK) ||
+ args->dc.flags & XFS_DC_ALLOC_LEAF) {
+ if (!(args->dc.flags & XFS_DC_FOUND_LBLK)) {
+ error = xfs_attr_leaf_try_add(args, *leaf_bp);
+ args->dc.flags |= XFS_DC_FOUND_LBLK;
+
+ if (error && error != -ENOSPC)
+ return error;
+
+ return -EAGAIN;
+ }
+
+ error = xfs_leaf_addname_later(args);
+ if (error && error != -ENOSPC)
+ return error;
+ } else {
+ error = xfs_node_addname_later(args);
+ }
+
+ return error;
+}
+
+
+
+/*
* Return EEXIST if attr is found, or ENOATTR if not
*/
int
@@ -328,6 +437,57 @@ xfs_attr_remove_args(
return error;
}
+/*
+ * Remove the attribute specified in @args.
+ * This routine is meant to function as a delayed operation, and may return
+ * -EGAIN 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.
+ */
+int
+xfs_attr_remove_later(
+ struct xfs_da_args *args)
+{
+ struct xfs_inode *dp = args->dp;
+ struct xfs_buf *bp;
+ int forkoff, error = 0;
+
+ if (!xfs_inode_hasattr(dp)) {
+ error = -ENOATTR;
+ } else if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
+ ASSERT(dp->i_afp->if_flags & XFS_IFINLINE);
+ error = xfs_attr_shortform_remove(args);
+ } else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK) &&
+ !(args->dc.flags & XFS_DC_RM_NODE_BLKS)) {
+ /*
+ * If we fit in a block AND we are not in the middle of
+ * removing node blocks, remove the leaf attribute.
+ * xfs_attr_da_node_removename will set XFS_DC_RM_NODE_BLKS to
+ * signal that it is not done yet, and needs to be recalled to
+ * to finish up from the last -EAGAIN
+ */
+ error = xfs_leaf_has_attr(args, &bp);
+ if (error == -ENOATTR) {
+ xfs_trans_brelse(args->trans, bp);
+ return error;
+ }
+ error = 0;
+
+ xfs_attr3_leaf_remove(bp, args);
+
+ /* If the result is small enough, shrink it into the inode.*/
+ forkoff = xfs_attr_shortform_allfit(bp, dp);
+ if (forkoff)
+ error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
+ } else {
+ error = xfs_node_removename_later(args);
+ }
+
+ return error;
+}
+
+
+
int
xfs_attr_set(
struct xfs_inode *dp,
@@ -760,6 +920,87 @@ xfs_attr_leaf_addname(struct xfs_da_args *args)
}
/*
+ * Add a name to the leaf attribute list structure
+ *
+ * This leaf block cannot have a "remote" value, we only call this routine
+ * if bmap_one_block() says there is only one block (ie: no remote blks).
+ *
+ * This routine is meant to function as a delayed operation, and may return
+ * -EGAIN 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_leaf_addname_later(
+ struct xfs_da_args *args)
+{
+ int error, nmap;
+ struct xfs_inode *dp = args->dp;
+ struct xfs_bmbt_irec *map = &args->dc.map;
+
+ /*
+ * If there was an out-of-line value, allocate the blocks we
+ * identified for its storage and copy the value. This is done
+ * after we create the attribute so that we don't overflow the
+ * maximum size of a transaction and/or hit a deadlock.
+ */
+ if (args->rmtblkno > 0) {
+ if (!(args->dc.flags & XFS_DC_ALLOC_LEAF)) {
+ args->dc.lfileoff = 0;
+ args->dc.lblkno = 0;
+ args->dc.blkcnt = 0;
+ args->rmtblkcnt = 0;
+ args->rmtblkno = 0;
+ memset(map, 0, sizeof(struct xfs_bmbt_irec));
+
+ error = xfs_attr_rmt_find_hole(args);
+ if (error)
+ return error;
+
+ args->dc.blkcnt = args->rmtblkcnt;
+ args->dc.lblkno = args->rmtblkno;
+ args->dc.flags |= XFS_DC_ALLOC_LEAF;
+ }
+
+ /*
+ * Roll through the "value", allocating blocks on disk as
+ * required.
+ */
+ while (args->dc.blkcnt > 0) {
+ nmap = 1;
+ error = xfs_bmapi_write(args->trans, dp,
+ (xfs_fileoff_t)args->dc.lblkno,
+ args->dc.blkcnt, XFS_BMAPI_ATTRFORK,
+ args->total, map, &nmap);
+ if (error)
+ return error;
+ ASSERT(nmap == 1);
+ ASSERT((map->br_startblock != DELAYSTARTBLOCK) &&
+ (map->br_startblock != HOLESTARTBLOCK));
+
+ /* roll attribute extent map forwards */
+ args->dc.lblkno += map->br_blockcount;
+ args->dc.blkcnt -= map->br_blockcount;
+
+ return -EAGAIN;
+ }
+
+ error = xfs_attr_rmtval_set_value(args);
+ if (error)
+ return error;
+ }
+
+ if (args->rmtblkno > 0) {
+ /*
+ * Added a "remote" value, just clear the incomplete flag.
+ */
+ error = xfs_attr3_leaf_clearflag(args);
+ }
+ args->dc.flags &= ~XFS_DC_ALLOC_LEAF;
+ return error;
+}
+
+/*
* Return EEXIST if attr is found, or ENOATTR if not
*/
STATIC int
@@ -1259,6 +1500,355 @@ out:
}
/*
+ * Remove a name from a B-tree attribute list.
+ *
+ * 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 a delayed operation, and may return
+ * -EGAIN 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_node_removename_later(
+ struct xfs_da_args *args)
+{
+ struct xfs_da_state *state = NULL;
+ struct xfs_da_state_blk *blk;
+ struct xfs_buf *bp;
+ int error, forkoff, retval = 0;
+ struct xfs_inode *dp = args->dp;
+ int done = 0;
+
+ trace_xfs_attr_node_removename(args);
+
+ if (args->dc.state == NULL) {
+ error = xfs_attr_node_hasname(args, &args->dc.state);
+ if (error != -EEXIST)
+ goto out;
+ else
+ error = 0;
+
+ /*
+ * 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.
+ */
+ state = args->dc.state;
+ args->dc.blk = &state->path.blk[state->path.active - 1];
+ ASSERT(args->dc.blk->bp != NULL);
+ ASSERT(args->dc.blk->magic == XFS_ATTR_LEAF_MAGIC);
+ }
+ state = args->dc.state;
+ blk = args->dc.blk;
+
+ if (args->rmtblkno > 0 && !(args->dc.flags & XFS_DC_RM_LEAF_BLKS)) {
+ bool isset;
+
+ error = xfs_attr3_leaf_flag_is_set(args, &isset);
+ if (error)
+ goto out;
+ if (!isset) {
+ /*
+ * Fill in disk block numbers in the state structure
+ * so that we can get the buffers back after we commit
+ * several transactions in the following calls.
+ */
+ error = xfs_attr_fillstate(state);
+ if (error)
+ goto out;
+
+ /*
+ * Mark the attribute as INCOMPLETE, then bunmapi() the
+ * remote value.
+ */
+ error = xfs_attr3_leaf_setflag(args);
+ if (error)
+ goto out;
+
+ return -EAGAIN;
+ }
+
+ if (!(args->dc.flags & XFS_DC_RM_NODE_BLKS)) {
+ args->dc.flags |= XFS_DC_RM_NODE_BLKS;
+ error = xfs_attr_rmtval_invalidate(args);
+ if (error)
+ goto out;
+ }
+
+ /*
+ * Unmap value blocks for this attr. This is similar to
+ * xfs_attr_rmtval_remove, but open coded here to return EAGAIN
+ * for new transactions
+ */
+ while (!done && !error) {
+ error = xfs_bunmapi(args->trans, args->dp,
+ args->rmtblkno, args->rmtblkcnt,
+ XFS_BMAPI_ATTRFORK, 1, &done);
+ if (error)
+ return error;
+
+ if (!done)
+ return -EAGAIN;
+ }
+
+ if (error)
+ goto out;
+
+ /*
+ * Refill the state structure with buffers, the prior calls
+ * released our buffers.
+ */
+ error = xfs_attr_refillstate(state);
+ if (error)
+ goto out;
+ }
+
+ /*
+ * Remove the name and update the hashvals in the tree.
+ */
+ if (!(args->dc.flags & XFS_DC_RM_LEAF_BLKS)) {
+ blk = &state->path.blk[state->path.active - 1];
+ ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
+ retval = xfs_attr3_leaf_remove(blk->bp, args);
+ xfs_da3_fixhashpath(state, &state->path);
+
+ args->dc.flags |= XFS_DC_RM_LEAF_BLKS;
+ }
+
+ /*
+ * Check to see if the tree needs to be collapsed.
+ */
+ if (retval && (state->path.active > 1)) {
+ args->dc.flags |= XFS_DC_RM_NODE_BLKS;
+ error = xfs_da3_join(state);
+ if (error)
+ goto out;
+
+ return -EAGAIN;
+ }
+
+ /*
+ * If the result is small enough, push it all into the inode.
+ */
+ if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
+ /*
+ * Have to get rid of the copy of this dabuf in the state.
+ */
+ ASSERT(state->path.active == 1);
+ ASSERT(state->path.blk[0].bp);
+ state->path.blk[0].bp = NULL;
+
+ error = xfs_attr3_leaf_read(args->trans, args->dp, 0, -1, &bp);
+ if (error)
+ goto out;
+
+ forkoff = xfs_attr_shortform_allfit(bp, dp);
+ if (forkoff) {
+ error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
+ /* bp is gone due to xfs_da_shrink_inode */
+ if (error)
+ goto out;
+ } else
+ xfs_trans_brelse(args->trans, bp);
+ }
+out:
+ if (state != NULL)
+ xfs_da_state_free(state);
+
+ return error;
+}
+
+/*
+ * Add a name to a Btree-format attribute list.
+ *
+ * This will involve walking down the Btree, and may involve splitting
+ * leaf nodes and even splitting intermediate nodes up to and including
+ * the root node (a special case of an intermediate node).
+ *
+ * "Remote" attribute values confuse the issue and atomic rename operations
+ * add a whole extra layer of confusion on top of that.
+ *
+ * This routine is meant to function as a delayed operation, and may return
+ * -EGAIN 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_node_addname_later(
+ struct xfs_da_args *args)
+{
+ struct xfs_da_state *state = NULL;
+ struct xfs_da_state_blk *blk;
+ struct xfs_inode *dp;
+ int retval = 0;
+ int error = 0;
+ int nmap;
+ struct xfs_bmbt_irec *map = &args->dc.map;
+
+ trace_xfs_attr_node_addname(args);
+
+ /*
+ * Fill in bucket of arguments/results/context to carry around.
+ */
+ dp = args->dp;
+
+ if (args->dc.flags & XFS_DC_FOUND_NBLK)
+ goto found_blk;
+
+ /*
+ * Search to see if name already exists, and get back a pointer
+ * to where it should go.
+ */
+ retval = xfs_attr_node_hasname(args, &state);
+ blk = &state->path.blk[state->path.active-1];
+ ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
+ if ((args->name.type & ATTR_REPLACE) && (retval == -ENOATTR)) {
+ goto out;
+ } else if (retval == -EEXIST) {
+ if (args->name.type & ATTR_CREATE)
+ goto out;
+
+ trace_xfs_attr_node_replace(args);
+
+ /* save the attribute state for later removal*/
+ args->op_flags |= XFS_DA_OP_RENAME; /* atomic rename op */
+ args->blkno2 = args->blkno; /* set 2nd entry info*/
+ args->index2 = args->index;
+ args->rmtblkno2 = args->rmtblkno;
+ args->rmtblkcnt2 = args->rmtblkcnt;
+ args->rmtvaluelen2 = args->rmtvaluelen;
+
+ /*
+ * clear the remote attr state now that it is saved so that the
+ * values reflect the state of the attribute we are about to
+ * add, not the attribute we just found and will remove later.
+ */
+ args->rmtblkno = 0;
+ args->rmtblkcnt = 0;
+ args->rmtvaluelen = 0;
+ }
+
+ retval = xfs_attr3_leaf_add(blk->bp, state->args);
+ if (retval == -ENOSPC) {
+ if (state->path.active == 1) {
+ /*
+ * Its really a single leaf node, but it had
+ * out-of-line values so it looked like it *might*
+ * have been a b-tree.
+ */
+ xfs_da_state_free(state);
+ state = NULL;
+ error = xfs_attr3_leaf_to_node(args);
+ if (error)
+ goto out;
+
+ return -EAGAIN;
+ }
+
+ /*
+ * Split as many Btree elements as required.
+ * This code tracks the new and old attr's location
+ * in the index/blkno/rmtblkno/rmtblkcnt fields and
+ * in the index2/blkno2/rmtblkno2/rmtblkcnt2 fields.
+ */
+ error = xfs_da3_split(state);
+ if (error)
+ goto out;
+ } else {
+ /*
+ * Addition succeeded, update Btree hashvals.
+ */
+ xfs_da3_fixhashpath(state, &state->path);
+ }
+
+ /*
+ * Kill the state structure, we're done with it and need to
+ * allow the buffers to come back later.
+ */
+ xfs_da_state_free(state);
+ state = NULL;
+
+ args->dc.flags |= XFS_DC_FOUND_NBLK;
+ return -EAGAIN;
+found_blk:
+
+ /*
+ * If there was an out-of-line value, allocate the blocks we
+ * identified for its storage and copy the value. This is done
+ * after we create the attribute so that we don't overflow the
+ * maximum size of a transaction and/or hit a deadlock.
+ */
+ if (args->rmtblkno > 0) {
+ if (!(args->dc.flags & XFS_DC_ALLOC_NODE)) {
+ args->dc.flags |= XFS_DC_ALLOC_NODE;
+ args->dc.lblkno = 0;
+ args->dc.lfileoff = 0;
+ args->dc.blkcnt = 0;
+ args->rmtblkcnt = 0;
+ args->rmtblkno = 0;
+ memset(map, 0, sizeof(struct xfs_bmbt_irec));
+
+ error = xfs_attr_rmt_find_hole(args);
+ if (error)
+ return error;
+
+ args->dc.blkcnt = args->rmtblkcnt;
+ args->dc.lblkno = args->rmtblkno;
+ }
+ /*
+ * Roll through the "value", allocating blocks on disk as
+ * required.
+ */
+ while (args->dc.blkcnt > 0) {
+ nmap = 1;
+ error = xfs_bmapi_write(args->trans, dp,
+ (xfs_fileoff_t)args->dc.lblkno, args->dc.blkcnt,
+ XFS_BMAPI_ATTRFORK, args->total, map, &nmap);
+ if (error)
+ return error;
+
+ ASSERT(nmap == 1);
+ ASSERT((map->br_startblock != DELAYSTARTBLOCK) &&
+ (map->br_startblock != HOLESTARTBLOCK));
+
+ /* roll attribute extent map forwards */
+ args->dc.lblkno += map->br_blockcount;
+ args->dc.blkcnt -= map->br_blockcount;
+
+ return -EAGAIN;
+ }
+
+ error = xfs_attr_rmtval_set_value(args);
+ if (error)
+ return error;
+ }
+
+ if (args->rmtblkno > 0) {
+ /*
+ * Added a "remote" value, just clear the incomplete flag.
+ */
+ error = xfs_attr3_leaf_clearflag(args);
+ if (error)
+ goto out;
+ }
+ retval = error = 0;
+
+out:
+ if (state)
+ xfs_da_state_free(state);
+ if (error)
+ return error;
+
+ return retval;
+}
+
+
+
+/*
* Fill in the disk block numbers in the state structure for the buffers
* that are attached to the state structure.
* This is done so that we can quickly reattach ourselves to those buffers
diff --git a/libxfs/xfs_attr.h b/libxfs/xfs_attr.h
index 6bd783c..9828728 100644
--- a/libxfs/xfs_attr.h
+++ b/libxfs/xfs_attr.h
@@ -147,9 +147,11 @@ int xfs_attr_get(struct xfs_inode *ip, struct xfs_name *name,
int xfs_attr_set(struct xfs_inode *dp, struct xfs_name *name,
unsigned char *value, int valuelen);
int xfs_attr_set_args(struct xfs_da_args *args);
+int xfs_attr_set_later(struct xfs_da_args *args, struct xfs_buf **leaf_bp);
int xfs_attr_remove(struct xfs_inode *dp, struct xfs_name *name);
int xfs_has_attr(struct xfs_da_args *args);
int xfs_attr_remove_args(struct xfs_da_args *args);
+int xfs_attr_remove_later(struct xfs_da_args *args);
int xfs_attr_list(struct xfs_inode *dp, char *buffer, int bufsize,
int flags, struct attrlist_cursor_kern *cursor);
bool xfs_attr_namecheck(const void *name, size_t length);
--
2.7.4
