diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index 4773eef9d3de31812a18fd1f05579d7570a5b72e..510ca69746042b3a86fdd5a4897609fbf80d8280 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -118,12 +118,28 @@ xfs_attr_get_ilocked(
return xfs_attr_node_get(args);
}
-/* Retrieve an extended attribute by name, and its value. */
+/*
+ * Retrieve an extended attribute by name, and its value if requested.
+ *
+ * If ATTR_KERNOVAL is set in @flags, then the caller does not want the value,
+ * just an indication whether the attribute exists and the size of the value if
+ * it exists. The size is returned in @valuelenp,
+ *
+ * If the attribute is found, but exceeds the size limit set by the caller in
+ * @valuelenp, return -ERANGE with the size of the attribute that was found in
+ * @valuelenp.
+ *
+ * If ATTR_ALLOC is set in @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(
struct xfs_inode *ip,
const unsigned char *name,
- unsigned char *value,
+ unsigned char **value,
int *valuelenp,
int flags)
{
@@ -131,6 +147,8 @@ xfs_attr_get(
uint lock_mode;
int error;
+ ASSERT((flags & (ATTR_ALLOC | ATTR_KERNOVAL)) || *value);
+
XFS_STATS_INC(ip->i_mount, xs_attr_get);
if (XFS_FORCED_SHUTDOWN(ip->i_mount))
@@ -140,17 +158,29 @@ xfs_attr_get(
if (error)
return error;
- args.value = value;
- args.valuelen = *valuelenp;
/* Entirely possible to look up a name which doesn't exist */
args.op_flags = XFS_DA_OP_OKNOENT;
+ if (flags & ATTR_ALLOC)
+ args.op_flags |= XFS_DA_OP_ALLOCVAL;
+ else
+ args.value = *value;
+ args.valuelen = *valuelenp;
lock_mode = xfs_ilock_attr_map_shared(ip);
error = xfs_attr_get_ilocked(ip, &args);
xfs_iunlock(ip, lock_mode);
-
*valuelenp = args.valuelen;
- return error;
+
+ /* on error, we have to clean up allocated value buffers */
+ if (error) {
+ if (flags & ATTR_ALLOC) {
+ kmem_free(args.value);
+ *value = NULL;
+ }
+ return error;
+ }
+ *value = args.value;
+ return 0;
}
/*
diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
index ff28ebf3b635d1940f1306006623a072602ecd5f..94badfa1743e372ef9b34125e83a0ddb6ae181ca 100644
--- a/fs/xfs/libxfs/xfs_attr.h
+++ b/fs/xfs/libxfs/xfs_attr.h
@@ -37,6 +37,7 @@ struct xfs_attr_list_context;
#define ATTR_KERNOVAL 0x2000 /* [kernel] get attr size only, not value */
#define ATTR_INCOMPLETE 0x4000 /* [kernel] return INCOMPLETE attr keys */
+#define ATTR_ALLOC 0x8000 /* allocate xattr buffer on demand */
#define XFS_ATTR_FLAGS \
{ ATTR_DONTFOLLOW, "DONTFOLLOW" }, \
@@ -47,7 +48,8 @@ struct xfs_attr_list_context;
{ ATTR_REPLACE, "REPLACE" }, \
{ ATTR_KERNOTIME, "KERNOTIME" }, \
{ ATTR_KERNOVAL, "KERNOVAL" }, \
- { ATTR_INCOMPLETE, "INCOMPLETE" }
+ { ATTR_INCOMPLETE, "INCOMPLETE" }, \
+ { ATTR_ALLOC, "ALLOC" }
/*
* The maximum size (into the kernel or returned from the kernel) of an
@@ -143,7 +145,7 @@ int xfs_attr_list_int(struct xfs_attr_list_context *);
int xfs_inode_hasattr(struct xfs_inode *ip);
int xfs_attr_get_ilocked(struct xfs_inode *ip, struct xfs_da_args *args);
int xfs_attr_get(struct xfs_inode *ip, const unsigned char *name,
- unsigned char *value, int *valuelenp, int flags);
+ unsigned char **value, int *valuelenp, int flags);
int xfs_attr_set(struct xfs_inode *dp, const unsigned char *name,
unsigned char *value, int valuelen, int flags);
int xfs_attr_set_args(struct xfs_da_args *args);
diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c
index f6a595e7634358270f00d140a2f65879fd54c956..b9f019603d0b7f2fa5e5bcc6cc1a4cc0f06dbeb2 100644
--- a/fs/xfs/libxfs/xfs_attr_leaf.c
+++ b/fs/xfs/libxfs/xfs_attr_leaf.c
@@ -414,6 +414,12 @@ xfs_attr_copy_value(
args->valuelen = valuelen;
return -ERANGE;
}
+
+ if (args->op_flags & XFS_DA_OP_ALLOCVAL) {
+ args->value = kmem_alloc_large(valuelen, 0);
+ if (!args->value)
+ return -ENOMEM;
+ }
args->valuelen = valuelen;
/* remote block xattr requires IO for copy-in */
diff --git a/fs/xfs/libxfs/xfs_da_btree.h b/fs/xfs/libxfs/xfs_da_btree.h
index 84dd865b6c3d8cb30d25c38aaecebad9d5a82e9a..ae0bbd20d9caf141a7ae7c57803c57006f9e3d58 100644
--- a/fs/xfs/libxfs/xfs_da_btree.h
+++ b/fs/xfs/libxfs/xfs_da_btree.h
@@ -81,13 +81,15 @@ 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_FLAGS \
{ XFS_DA_OP_JUSTCHECK, "JUSTCHECK" }, \
{ XFS_DA_OP_RENAME, "RENAME" }, \
{ XFS_DA_OP_ADDNAME, "ADDNAME" }, \
{ XFS_DA_OP_OKNOENT, "OKNOENT" }, \
- { XFS_DA_OP_CILOOKUP, "CILOOKUP" }
+ { XFS_DA_OP_CILOOKUP, "CILOOKUP" }, \
+ { XFS_DA_OP_ALLOCVAL, "ALLOCVAL" }
/*
* Storage for holding state during Btree searches and split/join ops.
diff --git a/fs/xfs/xfs_acl.c b/fs/xfs/xfs_acl.c
index 86c0697870a5b42901d615d5bf26476b7f78ed16..96d7071cfa4689435aeaf2ed34a7d58bb3e7bc2c 100644
--- a/fs/xfs/xfs_acl.c
+++ b/fs/xfs/xfs_acl.c
@@ -112,7 +112,7 @@ xfs_get_acl(struct inode *inode, int type)
{
struct xfs_inode *ip = XFS_I(inode);
struct posix_acl *acl = NULL;
- struct xfs_acl *xfs_acl;
+ struct xfs_acl *xfs_acl = NULL;
unsigned char *ea_name;
int error;
int len;
@@ -135,12 +135,8 @@ xfs_get_acl(struct inode *inode, int type)
* go out to the disk.
*/
len = XFS_ACL_MAX_SIZE(ip->i_mount);
- xfs_acl = kmem_zalloc_large(len, 0);
- if (!xfs_acl)
- return ERR_PTR(-ENOMEM);
-
- error = xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl,
- &len, ATTR_ROOT);
+ error = xfs_attr_get(ip, ea_name, (unsigned char **)&xfs_acl, &len,
+ ATTR_ALLOC | ATTR_ROOT);
if (error) {
/*
* If the attribute doesn't exist make sure we have a negative
@@ -151,8 +147,8 @@ xfs_get_acl(struct inode *inode, int type)
} else {
acl = xfs_acl_from_disk(xfs_acl, len,
XFS_ACL_MAX_ENTRIES(ip->i_mount));
+ kmem_free(xfs_acl);
}
- kmem_free(xfs_acl);
return acl;
}
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index e6f1e47397582986b8de33205376a151ce3cb247..495565feae4fd8efda7bff15bdc7400a183b5ead 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -438,7 +438,7 @@ xfs_attrmulti_attr_get(
if (!kbuf)
return -ENOMEM;
- error = xfs_attr_get(XFS_I(inode), name, kbuf, (int *)len, flags);
+ error = xfs_attr_get(XFS_I(inode), name, &kbuf, (int *)len, flags);
if (error)
goto out_kfree;
diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
index 3123b5aaad2a15ef3652892372c7808ebc091dd5..cb895b1df5e4256dc5ead4ef892d000afc83c8d5 100644
--- a/fs/xfs/xfs_xattr.c
+++ b/fs/xfs/xfs_xattr.c
@@ -30,7 +30,7 @@ xfs_xattr_get(const struct xattr_handler *handler, struct dentry *unused,
value = NULL;
}
- error = xfs_attr_get(ip, (unsigned char *)name, value, &asize, xflags);
+ error = xfs_attr_get(ip, name, (unsigned char **)&value, &asize, xflags);
if (error)
return error;
return asize;