diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c index 4773eef9d3de..510ca6974604 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 ff28ebf3b635..94badfa1743e 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 f6a595e76343..b9f019603d0b 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 84dd865b6c3d..ae0bbd20d9ca 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 86c0697870a5..96d7071cfa46 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 e6f1e4739758..495565feae4f 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 3123b5aaad2a..cb895b1df5e4 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;