[PATCH 18/33] xfs: remove ATTR_ALLOC and XFS_DA_OP_ALLOCVAL

Christoph Hellwig
2019-12-12T10:55:22Z

Use a NULL args->value as the indicator to lazily allocate a buffer
instead, and let the caller always free args->value instead of
duplicating the cleanup.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/libxfs/xfs_attr.c | 20 +++++---------------
fs/xfs/libxfs/xfs_attr.h | 7 ++-----
fs/xfs/libxfs/xfs_attr_leaf.c | 2 +-
fs/xfs/libxfs/xfs_types.h | 2 --
fs/xfs/xfs_acl.c | 20 ++++++++++----------
5 files changed, 18 insertions(+), 33 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index 1c4e8ac38d5a..c362dbab1a6a 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -98,15 +98,14 @@ xfs_attr_get_ilocked(
* indication whether the attribute exists and the size of the value if it
* exists. The size is returned in args.valuelen.
*
+ * If args->value is NULL but args->valuelen is non-zero, allocate the buffer
+ * for the value after existence of the attribute has been determined. The
+ * caller always has to free args->value if it is set, no matter if this
+ * function was successful or not.
+ *
* If the attribute is found, but exceeds the size limit set by the caller in
* args->valuelen, return -ERANGE with the size of the attribute that was found
* in args->valuelen.
- *
- * If ATTR_ALLOC is set in args->flags, allocate the buffer for the value after
- * existence of the attribute has been determined. On success, return that
- * buffer to the caller and leave them to free it. On failure, free any
- * allocated buffer and ensure the buffer pointer returned to the caller is
- * null.
*/
int
xfs_attr_get(
@@ -115,8 +114,6 @@ xfs_attr_get(
uint lock_mode;
int error;

- ASSERT((args->flags & ATTR_ALLOC) || !args->valuelen || args->value);
-
XFS_STATS_INC(args->dp->i_mount, xs_attr_get);

if (XFS_FORCED_SHUTDOWN(args->dp->i_mount))
@@ -128,18 +125,11 @@ xfs_attr_get(

/* Entirely possible to look up a name which doesn't exist */
args->op_flags = XFS_DA_OP_OKNOENT;
- if (args->flags & ATTR_ALLOC)
- args->op_flags |= XFS_DA_OP_ALLOCVAL;

lock_mode = xfs_ilock_attr_map_shared(args->dp);
error = xfs_attr_get_ilocked(args);
xfs_iunlock(args->dp, lock_mode);

- /* on error, we have to clean up allocated value buffers */
- if (error && (args->flags & ATTR_ALLOC)) {
- kmem_free(args->value);
- args->value = NULL;
- }
return error;
}

diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
index fe064cd81747..a6de050675c9 100644
--- a/fs/xfs/libxfs/xfs_attr.h
+++ b/fs/xfs/libxfs/xfs_attr.h
@@ -35,10 +35,8 @@ struct xfs_attr_list_context;

#define ATTR_KERNOTIME 0x1000 /* [kernel] don't update inode timestamps */

-#define ATTR_ALLOC 0x8000 /* [kernel] allocate xattr buffer on demand */
-
#define ATTR_KERNEL_FLAGS \
- (ATTR_KERNOTIME | ATTR_ALLOC)
+ (ATTR_KERNOTIME)

#define XFS_ATTR_FLAGS \
{ ATTR_DONTFOLLOW, "DONTFOLLOW" }, \
@@ -47,8 +45,7 @@ struct xfs_attr_list_context;
{ ATTR_SECURE, "SECURE" }, \
{ ATTR_CREATE, "CREATE" }, \
{ ATTR_REPLACE, "REPLACE" }, \
- { ATTR_KERNOTIME, "KERNOTIME" }, \
- { ATTR_ALLOC, "ALLOC" }
+ { ATTR_KERNOTIME, "KERNOTIME" }

/*
* The maximum size (into the kernel or returned from the kernel) of an
diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c
index 5e700dfc48a9..b0658eb8fbcc 100644
--- a/fs/xfs/libxfs/xfs_attr_leaf.c
+++ b/fs/xfs/libxfs/xfs_attr_leaf.c
@@ -477,7 +477,7 @@ xfs_attr_copy_value(
return -ERANGE;
}

- if (args->op_flags & XFS_DA_OP_ALLOCVAL) {
+ if (!args->value) {
args->value = kmem_alloc_large(valuelen, 0);
if (!args->value)
return -ENOMEM;
diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h
index 634814dd1d10..3379ebc0c7c5 100644
--- a/fs/xfs/libxfs/xfs_types.h
+++ b/fs/xfs/libxfs/xfs_types.h
@@ -223,7 +223,6 @@ typedef struct xfs_da_args {
#define XFS_DA_OP_ADDNAME 0x0004 /* this is an add operation */
#define XFS_DA_OP_OKNOENT 0x0008 /* lookup/add op, ENOENT ok, else die */
#define XFS_DA_OP_CILOOKUP 0x0010 /* lookup to return CI name if found */
-#define XFS_DA_OP_ALLOCVAL 0x0020 /* lookup to alloc buffer if found */
#define XFS_DA_OP_INCOMPLETE 0x0040 /* lookup INCOMPLETE attr keys */

#define XFS_DA_OP_FLAGS \
@@ -232,7 +231,6 @@ typedef struct xfs_da_args {
{ XFS_DA_OP_ADDNAME, "ADDNAME" }, \
{ XFS_DA_OP_OKNOENT, "OKNOENT" }, \
{ XFS_DA_OP_CILOOKUP, "CILOOKUP" }, \
- { XFS_DA_OP_ALLOCVAL, "ALLOCVAL" }, \
{ XFS_DA_OP_INCOMPLETE, "INCOMPLETE" }

/*
diff --git a/fs/xfs/xfs_acl.c b/fs/xfs/xfs_acl.c
index c72003b73926..7d417e6b1484 100644
--- a/fs/xfs/xfs_acl.c
+++ b/fs/xfs/xfs_acl.c
@@ -125,7 +125,7 @@ xfs_get_acl(struct inode *inode, int type)
struct posix_acl *acl = NULL;
struct xfs_da_args args = {
.dp = ip,
- .flags = ATTR_ALLOC | ATTR_ROOT,
+ .flags = ATTR_ROOT,
.valuelen = XFS_ACL_MAX_SIZE(mp),
};
int error;
@@ -144,19 +144,19 @@ xfs_get_acl(struct inode *inode, int type)
}
args.namelen = strlen(args.name);

+ /*
+ * If the attribute doesn't exist make sure we have a negative cache
+ * entry, for any other error assume it is transient.
+ */
error = xfs_attr_get(&args);
- if (error) {
- /*
- * If the attribute doesn't exist make sure we have a negative
- * cache entry, for any other error assume it is transient.
- */
- if (error != -ENOATTR)
- acl = ERR_PTR(error);
- } else {
+ if (!error) {
acl = xfs_acl_from_disk(mp, args.value, args.valuelen,
XFS_ACL_MAX_ENTRIES(mp));
- kmem_free(args.value);
+ } else if (error != -ENOATTR) {
+ acl = ERR_PTR(error);
}
+
+ kmem_free(args.value);
return acl;
}

--
2.20.1