[PATCH v1 05/19] xfsprogs: Add xfs_has_attr and subroutines

Allison Collins
2019-08-09T21:38:19Z

This patch adds a new functions to check for the existence of
an attribute. Subroutines are also added to handle the cases
of leaf blocks, nodes or shortform. Common code that appears
in existing attr add and remove functions have been factored
out to help reduce the appearence of duplicated code. We will
need these routines later for delayed attributes since delayed
operations cannot return error codes.

Signed-off-by: Allison Collins <allison.henderson@oracle.com>
---
libxfs/xfs_attr.c | 151 ++++++++++++++++++++++++++++++++-----------------
libxfs/xfs_attr.h | 1 +
libxfs/xfs_attr_leaf.c | 82 ++++++++++++++++++---------
libxfs/xfs_attr_leaf.h | 2 +
4 files changed, 158 insertions(+), 78 deletions(-)

diff --git a/libxfs/xfs_attr.c b/libxfs/xfs_attr.c
index 4690538..f082b30 100644
--- a/libxfs/xfs_attr.c
+++ b/libxfs/xfs_attr.c
@@ -49,6 +49,7 @@ STATIC int xfs_attr_shortform_addname(xfs_da_args_t *args);
STATIC int xfs_attr_leaf_get(xfs_da_args_t *args);
STATIC int xfs_attr_leaf_addname(xfs_da_args_t *args);
STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args);
+STATIC int xfs_leaf_has_attr(xfs_da_args_t *args, struct xfs_buf **bp);

/*
* Internal routines when attribute list is more than one block.
@@ -56,6 +57,8 @@ STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args);
STATIC int xfs_attr_node_get(xfs_da_args_t *args);
STATIC int xfs_attr_node_addname(xfs_da_args_t *args);
STATIC int xfs_attr_node_removename(xfs_da_args_t *args);
+STATIC int xfs_attr_node_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);

@@ -279,6 +282,32 @@ xfs_attr_set_args(
}

/*
+ * Return EEXIST if attr is found, or ENOATTR if not
+ */
+int
+xfs_has_attr(
+ struct xfs_da_args *args)
+{
+ struct xfs_inode *dp = args->dp;
+ struct xfs_buf *bp;
+ int error;
+
+ 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_shortform_has_attr(args, NULL, NULL);
+ } else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
+ error = xfs_leaf_has_attr(args, &bp);
+ xfs_trans_brelse(args->trans, bp);
+ } else {
+ error = xfs_attr_node_hasname(args, NULL);
+ }
+
+ return error;
+}
+
+/*
* Remove the attribute specified in @args.
*/
int
@@ -617,26 +646,17 @@ STATIC int
xfs_attr_leaf_addname(
struct xfs_da_args *args)
{
- struct xfs_inode *dp;
struct xfs_buf *bp;
int retval, error, forkoff;
+ struct xfs_inode *dp = args->dp;

trace_xfs_attr_leaf_addname(args);

/*
- * Read the (only) block in the attribute list in.
- */
- dp = args->dp;
- args->blkno = 0;
- error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, -1, &bp);
- if (error)
- return error;
-
- /*
* Look up the given attribute in the leaf block. Figure out if
* the given flags produce an error or call for an atomic rename.
*/
- retval = xfs_attr3_leaf_lookup_int(bp, args);
+ retval = xfs_leaf_has_attr(args, &bp);
if ((args->flags & ATTR_REPLACE) && (retval == -ENOATTR)) {
xfs_trans_brelse(args->trans, bp);
return retval;
@@ -788,6 +808,26 @@ xfs_attr_leaf_addname(
}

/*
+ * Return EEXIST if attr is found, or ENOATTR if not
+ */
+STATIC int
+xfs_leaf_has_attr(
+ struct xfs_da_args *args,
+ struct xfs_buf **bp)
+{
+ int error = 0;
+
+ args->blkno = 0;
+ error = xfs_attr3_leaf_read(args->trans, args->dp,
+ args->blkno, -1, bp);
+ if (error)
+ return error;
+
+ error = xfs_attr3_leaf_lookup_int(*bp, args);
+ return error;
+}
+
+/*
* Remove a name from the leaf attribute list structure
*
* This leaf block cannot have a "remote" value, we only call this routine
@@ -807,12 +847,8 @@ xfs_attr_leaf_removename(
* Remove the attribute.
*/
dp = args->dp;
- args->blkno = 0;
- error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, -1, &bp);
- if (error)
- return error;

- error = xfs_attr3_leaf_lookup_int(bp, args);
+ error = xfs_leaf_has_attr(args, &bp);
if (error == -ENOATTR) {
xfs_trans_brelse(args->trans, bp);
return error;
@@ -849,12 +885,7 @@ xfs_attr_leaf_get(xfs_da_args_t *args)

trace_xfs_attr_leaf_get(args);

- args->blkno = 0;
- error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, -1, &bp);
- if (error)
- return error;
-
- error = xfs_attr3_leaf_lookup_int(bp, args);
+ error = xfs_leaf_has_attr(args, &bp);
if (error != -EEXIST) {
xfs_trans_brelse(args->trans, bp);
return error;
@@ -867,6 +898,43 @@ xfs_attr_leaf_get(xfs_da_args_t *args)
return error;
}

+/*
+ * Return EEXIST if attr is found, or ENOATTR if not
+ * statep: If not null is set to point at the found state. Caller will
+ * be responsible for freeing the state in this case.
+ */
+STATIC int
+xfs_attr_node_hasname(
+ struct xfs_da_args *args,
+ struct xfs_da_state **statep)
+{
+ struct xfs_da_state *state;
+ struct xfs_inode *dp;
+ int retval, error;
+
+ /*
+ * Tie a string around our finger to remind us where we are.
+ */
+ dp = args->dp;
+ state = xfs_da_state_alloc();
+ state->args = args;
+ state->mp = dp->i_mount;
+
+ /*
+ * Search to see if name exists, and get back a pointer to it.
+ */
+ error = xfs_da3_node_lookup_int(state, &retval);
+ if (error == 0)
+ error = retval;
+
+ if (statep != NULL)
+ *statep = state;
+ else
+ xfs_da_state_free(state);
+
+ return error;
+}
+
/*========================================================================
* External routines when attribute list size > geo->blksize
*========================================================================*/
@@ -899,17 +967,14 @@ xfs_attr_node_addname(
dp = args->dp;
mp = dp->i_mount;
restart:
- state = xfs_da_state_alloc();
- state->args = args;
- state->mp = mp;
-
/*
* Search to see if name already exists, and get back a pointer
* to where it should go.
*/
- error = xfs_da3_node_lookup_int(state, &retval);
- if (error)
+ error = xfs_attr_node_hasname(args, &state);
+ if (error == -EEXIST)
goto out;
+
blk = &state->path.blk[ state->path.active-1 ];
ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
if ((args->flags & ATTR_REPLACE) && (retval == -ENOATTR)) {
@@ -1114,29 +1179,15 @@ xfs_attr_node_removename(
{
struct xfs_da_state *state;
struct xfs_da_state_blk *blk;
- struct xfs_inode *dp;
struct xfs_buf *bp;
int retval, error, forkoff;
+ struct xfs_inode *dp = args->dp;

trace_xfs_attr_node_removename(args);

- /*
- * Tie a string around our finger to remind us where we are.
- */
- dp = args->dp;
- state = xfs_da_state_alloc();
- state->args = args;
- state->mp = dp->i_mount;
-
- /*
- * Search to see if name exists, and get back a pointer to it.
- */
- error = xfs_da3_node_lookup_int(state, &retval);
- if (error || (retval != -EEXIST)) {
- if (error == 0)
- error = retval;
+ error = xfs_attr_node_hasname(args, &state);
+ if (error != -EEXIST)
goto out;
- }

/*
* If there is an out-of-line value, de-allocate the blocks.
@@ -1356,17 +1407,13 @@ xfs_attr_node_get(xfs_da_args_t *args)

trace_xfs_attr_node_get(args);

- state = xfs_da_state_alloc();
- state->args = args;
- state->mp = args->dp->i_mount;
-
/*
* Search to see if name exists, and get back a pointer to it.
*/
- error = xfs_da3_node_lookup_int(state, &retval);
- if (error) {
+ error = xfs_attr_node_hasname(args, &state);
+ if (error != -EEXIST) {
retval = error;
- } else if (retval == -EEXIST) {
+ } else {
blk = &state->path.blk[ state->path.active-1 ];
ASSERT(blk->bp != NULL);
ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
diff --git a/libxfs/xfs_attr.h b/libxfs/xfs_attr.h
index f4efa7c..06ed120 100644
--- a/libxfs/xfs_attr.h
+++ b/libxfs/xfs_attr.h
@@ -164,6 +164,7 @@ 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_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_list(struct xfs_inode *dp, char *buffer, int bufsize,
int flags, struct attrlist_cursor_kern *cursor);
diff --git a/libxfs/xfs_attr_leaf.c b/libxfs/xfs_attr_leaf.c
index 1027ca0..2ebe2c6 100644
--- a/libxfs/xfs_attr_leaf.c
+++ b/libxfs/xfs_attr_leaf.c
@@ -545,6 +545,53 @@ xfs_attr_shortform_create(xfs_da_args_t *args)
}

/*
+ * Return EEXIST if attr is found, or ENOATTR if not
+ * args: args containing attribute name and namelen
+ * sfep: If not null, pointer will be set to the last attr entry found
+ * basep: If not null, pointer is set to the byte offset of the entry in the
+ * list
+ */
+int
+xfs_shortform_has_attr(
+ struct xfs_da_args *args,
+ struct xfs_attr_sf_entry **sfep,
+ int *basep)
+{
+ struct xfs_attr_shortform *sf;
+ struct xfs_attr_sf_entry *sfe;
+ int base = sizeof(struct xfs_attr_sf_hdr);
+ int size = 0;
+ int end;
+ int i;
+
+ base = sizeof(struct xfs_attr_sf_hdr);
+ sf = (struct xfs_attr_shortform *)args->dp->i_afp->if_u1.if_data;
+ sfe = &sf->list[0];
+ end = sf->hdr.count;
+ for (i = 0; i < end; sfe = XFS_ATTR_SF_NEXTENTRY(sfe),
+ base += size, i++) {
+ size = XFS_ATTR_SF_ENTSIZE(sfe);
+ if (sfe->namelen != args->namelen)
+ continue;
+ if (memcmp(sfe->nameval, args->name, args->namelen) != 0)
+ continue;
+ if (!xfs_attr_namesp_match(args->flags, sfe->flags))
+ continue;
+ break;
+ }
+
+ if (sfep != NULL)
+ *sfep = sfe;
+
+ if (basep != NULL)
+ *basep = base;
+
+ if (i == end)
+ return -ENOATTR;
+ return -EEXIST;
+}
+
+/*
* Add a name/value pair to the shortform attribute list.
* Overflow from the inode has already been checked for.
*/
@@ -553,7 +600,7 @@ xfs_attr_shortform_add(xfs_da_args_t *args, int forkoff)
{
xfs_attr_shortform_t *sf;
xfs_attr_sf_entry_t *sfe;
- int i, offset, size;
+ int offset, size, error;
xfs_mount_t *mp;
xfs_inode_t *dp;
struct xfs_ifork *ifp;
@@ -567,18 +614,11 @@ xfs_attr_shortform_add(xfs_da_args_t *args, int forkoff)
ifp = dp->i_afp;
ASSERT(ifp->if_flags & XFS_IFINLINE);
sf = (xfs_attr_shortform_t *)ifp->if_u1.if_data;
- sfe = &sf->list[0];
- for (i = 0; i < sf->hdr.count; sfe = XFS_ATTR_SF_NEXTENTRY(sfe), i++) {
+ error = xfs_shortform_has_attr(args, &sfe, NULL);
#ifdef DEBUG
- if (sfe->namelen != args->namelen)
- continue;
- if (memcmp(args->name, sfe->nameval, args->namelen) != 0)
- continue;
- if (!xfs_attr_namesp_match(args->flags, sfe->flags))
- continue;
+ if (error == -EEXIST)
ASSERT(0);
#endif
- }

offset = (char *)sfe - (char *)sf;
size = XFS_ATTR_SF_ENTSIZE_BYNAME(args->namelen, args->valuelen);
@@ -625,7 +665,7 @@ xfs_attr_shortform_remove(xfs_da_args_t *args)
{
xfs_attr_shortform_t *sf;
xfs_attr_sf_entry_t *sfe;
- int base, size=0, end, totsize, i;
+ int base, size = 0, end, totsize, error;
xfs_mount_t *mp;
xfs_inode_t *dp;

@@ -633,23 +673,13 @@ xfs_attr_shortform_remove(xfs_da_args_t *args)

dp = args->dp;
mp = dp->i_mount;
- base = sizeof(xfs_attr_sf_hdr_t);
sf = (xfs_attr_shortform_t *)dp->i_afp->if_u1.if_data;
- sfe = &sf->list[0];
end = sf->hdr.count;
- for (i = 0; i < end; sfe = XFS_ATTR_SF_NEXTENTRY(sfe),
- base += size, i++) {
- size = XFS_ATTR_SF_ENTSIZE(sfe);
- if (sfe->namelen != args->namelen)
- continue;
- if (memcmp(sfe->nameval, args->name, args->namelen) != 0)
- continue;
- if (!xfs_attr_namesp_match(args->flags, sfe->flags))
- continue;
- break;
- }
- if (i == end)
- return -ENOATTR;
+
+ error = xfs_shortform_has_attr(args, &sfe, &base);
+ if (error == -ENOATTR)
+ return error;
+ size = XFS_ATTR_SF_ENTSIZE(sfe);

/*
* Fix up the attribute fork data, covering the hole
diff --git a/libxfs/xfs_attr_leaf.h b/libxfs/xfs_attr_leaf.h
index 7b74e18..be1f636 100644
--- a/libxfs/xfs_attr_leaf.h
+++ b/libxfs/xfs_attr_leaf.h
@@ -39,6 +39,8 @@ int xfs_attr_shortform_getvalue(struct xfs_da_args *args);
int xfs_attr_shortform_to_leaf(struct xfs_da_args *args,
struct xfs_buf **leaf_bp);
int xfs_attr_shortform_remove(struct xfs_da_args *args);
+int xfs_shortform_has_attr(struct xfs_da_args *args,
+ struct xfs_attr_sf_entry **sfep, int *basep);
int xfs_attr_shortform_allfit(struct xfs_buf *bp, struct xfs_inode *dp);
int xfs_attr_shortform_bytesfit(struct xfs_inode *dp, int bytes);
xfs_failaddr_t xfs_attr_shortform_verify(struct xfs_inode *ip);
--
2.7.4