Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 621 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
new file mode 100644
index 000000000..81be9b3e4
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_attr.h
@@ -0,0 +1,621 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2000,2002-2003,2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#ifndef __XFS_ATTR_H__
+#define	__XFS_ATTR_H__
+
+struct xfs_inode;
+struct xfs_da_args;
+struct xfs_attr_list_context;
+
+/*
+ * Large attribute lists are structured around Btrees where all the data
+ * elements are in the leaf nodes.  Attribute names are hashed into an int,
+ * then that int is used as the index into the Btree.  Since the hashval
+ * of an attribute name may not be unique, we may have duplicate keys.
+ * The internal links in the Btree are logical block offsets into the file.
+ *
+ * Small attribute lists use a different format and are packed as tightly
+ * as possible so as to fit into the literal area of the inode.
+ */
+
+/*
+ * The maximum size (into the kernel or returned from the kernel) of an
+ * attribute value or the buffer used for an attr_list() call.  Larger
+ * sizes will result in an ERANGE return code.
+ */
+#define	ATTR_MAX_VALUELEN	(64*1024)	/* max length of a value */
+
+/*
+ * Kernel-internal version of the attrlist cursor.
+ */
+struct xfs_attrlist_cursor_kern {
+	__u32	hashval;	/* hash value of next entry to add */
+	__u32	blkno;		/* block containing entry (suggestion) */
+	__u32	offset;		/* offset in list of equal-hashvals */
+	__u16	pad1;		/* padding to match user-level */
+	__u8	pad2;		/* padding to match user-level */
+	__u8	initted;	/* T/F: cursor has been initialized */
+};
+
+
+/*========================================================================
+ * Structure used to pass context around among the routines.
+ *========================================================================*/
+
+
+/* void; state communicated via *context */
+typedef void (*put_listent_func_t)(struct xfs_attr_list_context *, int,
+			      unsigned char *, int, int);
+
+struct xfs_attr_list_context {
+	struct xfs_trans	*tp;
+	struct xfs_inode	*dp;		/* inode */
+	struct xfs_attrlist_cursor_kern cursor;	/* position in list */
+	void			*buffer;	/* output buffer */
+
+	/*
+	 * Abort attribute list iteration if non-zero.  Can be used to pass
+	 * error values to the xfs_attr_list caller.
+	 */
+	int			seen_enough;
+	bool			allow_incomplete;
+
+	ssize_t			count;		/* num used entries */
+	int			dupcnt;		/* count dup hashvals seen */
+	int			bufsize;	/* total buffer size */
+	int			firstu;		/* first used byte in buffer */
+	unsigned int		attr_filter;	/* XFS_ATTR_{ROOT,SECURE} */
+	int			resynch;	/* T/F: resynch with cursor */
+	put_listent_func_t	put_listent;	/* list output fmt function */
+	int			index;		/* index into output buffer */
+};
+
+
+/*
+ * ========================================================================
+ * Structure used to pass context around among the delayed routines.
+ * ========================================================================
+ */
+
+/*
+ * Below is a state machine diagram for attr remove operations. The  XFS_DAS_*
+ * states indicate places where the function would return -EAGAIN, and then
+ * immediately resume from after being called by the calling function. States
+ * marked as a "subroutine state" indicate that they belong to a subroutine, and
+ * so the calling function needs to pass them back to that subroutine to allow
+ * it to finish where it left off. But they otherwise do not have a role in the
+ * calling function other than just passing through.
+ *
+ * xfs_attr_remove_iter()
+ *              │
+ *              v
+ *        have attr to remove? ──n──> done
+ *              │
+ *              y
+ *              │
+ *              v
+ *        are we short form? ──y──> xfs_attr_shortform_remove ──> done
+ *              │
+ *              n
+ *              │
+ *              V
+ *        are we leaf form? ──y──> xfs_attr_leaf_removename ──> done
+ *              │
+ *              n
+ *              │
+ *              V
+ *   ┌── need to setup state?
+ *   │          │
+ *   n          y
+ *   │          │
+ *   │          v
+ *   │ find attr and get state
+ *   │ attr has remote blks? ──n─┐
+ *   │          │                v
+ *   │          │         find and invalidate
+ *   │          y         the remote blocks.
+ *   │          │         mark attr incomplete
+ *   │          ├────────────────┘
+ *   └──────────┤
+ *              │
+ *              v
+ *   Have remote blks to remove? ───y─────┐
+ *              │        ^          remove the blks
+ *              │        │                │
+ *              │        │                v
+ *              │  XFS_DAS_RMTBLK <─n── done?
+ *              │  re-enter with          │
+ *              │  one less blk to        y
+ *              │      remove             │
+ *              │                         V
+ *              │                  refill the state
+ *              n                         │
+ *              │                         v
+ *              │                   XFS_DAS_RM_NAME
+ *              │                         │
+ *              ├─────────────────────────┘
+ *              │
+ *              v
+ *       remove leaf and
+ *       update hash with
+ *   xfs_attr_node_remove_cleanup
+ *              │
+ *              v
+ *           need to
+ *        shrink tree? ─n─┐
+ *              │         │
+ *              y         │
+ *              │         │
+ *              v         │
+ *          join leaf     │
+ *              │         │
+ *              v         │
+ *      XFS_DAS_RM_SHRINK │
+ *              │         │
+ *              v         │
+ *       do the shrink    │
+ *              │         │
+ *              v         │
+ *          free state <──┘
+ *              │
+ *              v
+ *            done
+ *
+ *
+ * Below is a state machine diagram for attr set operations.
+ *
+ * It seems the challenge with understanding this system comes from trying to
+ * absorb the state machine all at once, when really one should only be looking
+ * at it with in the context of a single function. Once a state sensitive
+ * function is called, the idea is that it "takes ownership" of the
+ * state machine. It isn't concerned with the states that may have belonged to
+ * it's calling parent. Only the states relevant to itself or any other
+ * subroutines there in. Once a calling function hands off the state machine to
+ * a subroutine, it needs to respect the simple rule that it doesn't "own" the
+ * state machine anymore, and it's the responsibility of that calling function
+ * to propagate the -EAGAIN back up the call stack. Upon reentry, it is
+ * committed to re-calling that subroutine until it returns something other than
+ * -EAGAIN. Once that subroutine signals completion (by returning anything other
+ * than -EAGAIN), the calling function can resume using the state machine.
+ *
+ *  xfs_attr_set_iter()
+ *              │
+ *              v
+ *   ┌─y─ has an attr fork?
+ *   │          |
+ *   │          n
+ *   │          |
+ *   │          V
+ *   │       add a fork
+ *   │          │
+ *   └──────────┤
+ *              │
+ *              V
+ *   ┌─── is shortform?
+ *   │          │
+ *   │          y
+ *   │          │
+ *   │          V
+ *   │   xfs_attr_set_fmt
+ *   │          |
+ *   │          V
+ *   │ xfs_attr_try_sf_addname
+ *   │          │
+ *   │          V
+ *   │      had enough ──y──> done
+ *   │        space?
+ *   n          │
+ *   │          n
+ *   │          │
+ *   │          V
+ *   │   transform to leaf
+ *   │          │
+ *   │          V
+ *   │   hold the leaf buffer
+ *   │          │
+ *   │          V
+ *   │     return -EAGAIN
+ *   │      Re-enter in
+ *   │       leaf form
+ *   │
+ *   └─> release leaf buffer
+ *          if needed
+ *              │
+ *              V
+ *   ┌───n── fork has
+ *   │      only 1 blk?
+ *   │          │
+ *   │          y
+ *   │          │
+ *   │          v
+ *   │ xfs_attr_leaf_try_add()
+ *   │          │
+ *   │          v
+ *   │      had enough ──────────────y─────────────┐
+ *   │        space?                               │
+ *   │          │                                  │
+ *   │          n                                  │
+ *   │          │                                  │
+ *   │          v                                  │
+ *   │    return -EAGAIN                           │
+ *   │      re-enter in                            │
+ *   │        node form                            │
+ *   │          │                                  │
+ *   └──────────┤                                  │
+ *              │                                  │
+ *              V                                  │
+ * xfs_attr_node_addname_find_attr                 │
+ *        determines if this                       │
+ *       is create or rename                       │
+ *     find space to store attr                    │
+ *              │                                  │
+ *              v                                  │
+ *     xfs_attr_node_addname                       │
+ *              │                                  │
+ *              v                                  │
+ *   fits in a node leaf? ────n─────┐              │
+ *              │     ^             v              │
+ *              │     │       single leaf node?    │
+ *              │     │         │            │     │
+ *              y     │         y            n     │
+ *              │     │         │            │     │
+ *              v     │         v            v     │
+ *            update  │    grow the leaf  split if │
+ *           hashvals └── return -EAGAIN   needed  │
+ *              │         retry leaf add     │     │
+ *              │           on reentry       │     │
+ *              ├────────────────────────────┘     │
+ *              │                                  │
+ *              v                                  │
+ *         need to alloc                           │
+ *   ┌─y── or flip flag?                           │
+ *   │          │                                  │
+ *   │          n                                  │
+ *   │          │                                  │
+ *   │          v                                  │
+ *   │         done                                │
+ *   │                                             │
+ *   │                                             │
+ *   │         XFS_DAS_FOUND_LBLK <────────────────┘
+ *   │                  │
+ *   │                  V
+ *   │        xfs_attr_leaf_addname()
+ *   │                  │
+ *   │                  v
+ *   │      ┌──first time through?
+ *   │      │          │
+ *   │      │          y
+ *   │      │          │
+ *   │      n          v
+ *   │      │    if we have rmt blks
+ *   │      │    find space for them
+ *   │      │          │
+ *   │      └──────────┤
+ *   │                 │
+ *   │                 v
+ *   │            still have
+ *   │      ┌─n─ blks to alloc? <──┐
+ *   │      │          │           │
+ *   │      │          y           │
+ *   │      │          │           │
+ *   │      │          v           │
+ *   │      │     alloc one blk    │
+ *   │      │     return -EAGAIN ──┘
+ *   │      │    re-enter with one
+ *   │      │    less blk to alloc
+ *   │      │
+ *   │      │
+ *   │      └───> set the rmt
+ *   │               value
+ *   │                 │
+ *   │                 v
+ *   │               was this
+ *   │              a rename? ──n─┐
+ *   │                 │          │
+ *   │                 y          │
+ *   │                 │          │
+ *   │                 v          │
+ *   │           flip incomplete  │
+ *   │               flag         │
+ *   │                 │          │
+ *   │                 v          │
+ *   │         XFS_DAS_FLIP_LFLAG │
+ *   │                 │          │
+ *   │                 v          │
+ *   │          need to remove    │
+ *   │              old bks? ──n──┤
+ *   │                 │          │
+ *   │                 y          │
+ *   │                 │          │
+ *   │                 V          │
+ *   │               remove       │
+ *   │        ┌───> old blks      │
+ *   │        │        │          │
+ *   │ XFS_DAS_RM_LBLK │          │
+ *   │        ^        │          │
+ *   │        │        v          │
+ *   │        └──y── more to      │
+ *   │              remove?       │
+ *   │                 │          │
+ *   │                 n          │
+ *   │                 │          │
+ *   │                 v          │
+ *   │          XFS_DAS_RD_LEAF   │
+ *   │                 │          │
+ *   │                 v          │
+ *   │            remove leaf     │
+ *   │                 │          │
+ *   │                 v          │
+ *   │            shrink to sf    │
+ *   │             if needed      │
+ *   │                 │          │
+ *   │                 v          │
+ *   │                done <──────┘
+ *   │
+ *   └──────> XFS_DAS_FOUND_NBLK
+ *                     │
+ *                     v
+ *       ┌─────n──  need to
+ *       │        alloc blks?
+ *       │             │
+ *       │             y
+ *       │             │
+ *       │             v
+ *       │        find space
+ *       │             │
+ *       │             v
+ *       │  ┌─>XFS_DAS_ALLOC_NODE
+ *       │  │          │
+ *       │  │          v
+ *       │  │      alloc blk
+ *       │  │          │
+ *       │  │          v
+ *       │  └──y── need to alloc
+ *       │         more blocks?
+ *       │             │
+ *       │             n
+ *       │             │
+ *       │             v
+ *       │      set the rmt value
+ *       │             │
+ *       │             v
+ *       │          was this
+ *       └────────> a rename? ──n─┐
+ *                     │          │
+ *                     y          │
+ *                     │          │
+ *                     v          │
+ *               flip incomplete  │
+ *                   flag         │
+ *                     │          │
+ *                     v          │
+ *             XFS_DAS_FLIP_NFLAG │
+ *                     │          │
+ *                     v          │
+ *                 need to        │
+ *               remove blks? ─n──┤
+ *                     │          │
+ *                     y          │
+ *                     │          │
+ *                     v          │
+ *                   remove       │
+ *        ┌────────> old blks     │
+ *        │            │          │
+ *  XFS_DAS_RM_NBLK    │          │
+ *        ^            │          │
+ *        │            v          │
+ *        └──────y── more to      │
+ *                   remove       │
+ *                     │          │
+ *                     n          │
+ *                     │          │
+ *                     v          │
+ *              XFS_DAS_CLR_FLAG  │
+ *                     │          │
+ *                     v          │
+ *                clear flags     │
+ *                     │          │
+ *                     ├──────────┘
+ *                     │
+ *                     v
+ *                   done
+ */
+
+/*
+ * Enum values for xfs_attr_intent.xattri_da_state
+ *
+ * These values are used by delayed attribute operations to keep track  of where
+ * they were before they returned -EAGAIN.  A return code of -EAGAIN signals the
+ * calling function to roll the transaction, and then call the subroutine to
+ * finish the operation.  The enum is then used by the subroutine to jump back
+ * to where it was and resume executing where it left off.
+ */
+enum xfs_delattr_state {
+	XFS_DAS_UNINIT		= 0,	/* No state has been set yet */
+
+	/*
+	 * Initial sequence states. The replace setup code relies on the
+	 * ADD and REMOVE states for a specific format to be sequential so
+	 * that we can transform the initial operation to be performed
+	 * according to the xfs_has_larp() state easily.
+	 */
+	XFS_DAS_SF_ADD,			/* Initial sf add state */
+	XFS_DAS_SF_REMOVE,		/* Initial sf replace/remove state */
+
+	XFS_DAS_LEAF_ADD,		/* Initial leaf add state */
+	XFS_DAS_LEAF_REMOVE,		/* Initial leaf replace/remove state */
+
+	XFS_DAS_NODE_ADD,		/* Initial node add state */
+	XFS_DAS_NODE_REMOVE,		/* Initial node replace/remove state */
+
+	/* Leaf state set/replace/remove sequence */
+	XFS_DAS_LEAF_SET_RMT,		/* set a remote xattr from a leaf */
+	XFS_DAS_LEAF_ALLOC_RMT,		/* We are allocating remote blocks */
+	XFS_DAS_LEAF_REPLACE,		/* Perform replace ops on a leaf */
+	XFS_DAS_LEAF_REMOVE_OLD,	/* Start removing old attr from leaf */
+	XFS_DAS_LEAF_REMOVE_RMT,	/* A rename is removing remote blocks */
+	XFS_DAS_LEAF_REMOVE_ATTR,	/* Remove the old attr from a leaf */
+
+	/* Node state sequence, must match leaf state above */
+	XFS_DAS_NODE_SET_RMT,		/* set a remote xattr from a node */
+	XFS_DAS_NODE_ALLOC_RMT,		/* We are allocating remote blocks */
+	XFS_DAS_NODE_REPLACE,		/* Perform replace ops on a node */
+	XFS_DAS_NODE_REMOVE_OLD,	/* Start removing old attr from node */
+	XFS_DAS_NODE_REMOVE_RMT,	/* A rename is removing remote blocks */
+	XFS_DAS_NODE_REMOVE_ATTR,	/* Remove the old attr from a node */
+
+	XFS_DAS_DONE,			/* finished operation */
+};
+
+#define XFS_DAS_STRINGS	\
+	{ XFS_DAS_UNINIT,		"XFS_DAS_UNINIT" }, \
+	{ XFS_DAS_SF_ADD,		"XFS_DAS_SF_ADD" }, \
+	{ XFS_DAS_SF_REMOVE,		"XFS_DAS_SF_REMOVE" }, \
+	{ XFS_DAS_LEAF_ADD,		"XFS_DAS_LEAF_ADD" }, \
+	{ XFS_DAS_LEAF_REMOVE,		"XFS_DAS_LEAF_REMOVE" }, \
+	{ XFS_DAS_NODE_ADD,		"XFS_DAS_NODE_ADD" }, \
+	{ XFS_DAS_NODE_REMOVE,		"XFS_DAS_NODE_REMOVE" }, \
+	{ XFS_DAS_LEAF_SET_RMT,		"XFS_DAS_LEAF_SET_RMT" }, \
+	{ XFS_DAS_LEAF_ALLOC_RMT,	"XFS_DAS_LEAF_ALLOC_RMT" }, \
+	{ XFS_DAS_LEAF_REPLACE,		"XFS_DAS_LEAF_REPLACE" }, \
+	{ XFS_DAS_LEAF_REMOVE_OLD,	"XFS_DAS_LEAF_REMOVE_OLD" }, \
+	{ XFS_DAS_LEAF_REMOVE_RMT,	"XFS_DAS_LEAF_REMOVE_RMT" }, \
+	{ XFS_DAS_LEAF_REMOVE_ATTR,	"XFS_DAS_LEAF_REMOVE_ATTR" }, \
+	{ XFS_DAS_NODE_SET_RMT,		"XFS_DAS_NODE_SET_RMT" }, \
+	{ XFS_DAS_NODE_ALLOC_RMT,	"XFS_DAS_NODE_ALLOC_RMT" },  \
+	{ XFS_DAS_NODE_REPLACE,		"XFS_DAS_NODE_REPLACE" },  \
+	{ XFS_DAS_NODE_REMOVE_OLD,	"XFS_DAS_NODE_REMOVE_OLD" }, \
+	{ XFS_DAS_NODE_REMOVE_RMT,	"XFS_DAS_NODE_REMOVE_RMT" }, \
+	{ XFS_DAS_NODE_REMOVE_ATTR,	"XFS_DAS_NODE_REMOVE_ATTR" }, \
+	{ XFS_DAS_DONE,			"XFS_DAS_DONE" }
+
+struct xfs_attri_log_nameval;
+
+/*
+ * Context used for keeping track of delayed attribute operations
+ */
+struct xfs_attr_intent {
+	/*
+	 * used to log this item to an intent containing a list of attrs to
+	 * commit later
+	 */
+	struct list_head		xattri_list;
+
+	/* Used in xfs_attr_node_removename to roll through removing blocks */
+	struct xfs_da_state		*xattri_da_state;
+
+	struct xfs_da_args		*xattri_da_args;
+
+	/*
+	 * Shared buffer containing the attr name and value so that the logging
+	 * code can share large memory buffers between log items.
+	 */
+	struct xfs_attri_log_nameval	*xattri_nameval;
+
+	/* Used to keep track of current state of delayed operation */
+	enum xfs_delattr_state		xattri_dela_state;
+
+	/*
+	 * Attr operation being performed - XFS_ATTRI_OP_FLAGS_*
+	 */
+	unsigned int			xattri_op_flags;
+
+	/* Used in xfs_attr_rmtval_set_blk to roll through allocating blocks */
+	xfs_dablk_t			xattri_lblkno;
+	int				xattri_blkcnt;
+	struct xfs_bmbt_irec		xattri_map;
+};
+
+
+/*========================================================================
+ * Function prototypes for the kernel.
+ *========================================================================*/
+
+/*
+ * Overall external interface routines.
+ */
+int xfs_attr_inactive(struct xfs_inode *dp);
+int xfs_attr_list_ilocked(struct xfs_attr_list_context *);
+int xfs_attr_list(struct xfs_attr_list_context *);
+int xfs_inode_hasattr(struct xfs_inode *ip);
+bool xfs_attr_is_leaf(struct xfs_inode *ip);
+int xfs_attr_get_ilocked(struct xfs_da_args *args);
+int xfs_attr_get(struct xfs_da_args *args);
+int xfs_attr_set(struct xfs_da_args *args);
+int xfs_attr_set_iter(struct xfs_attr_intent *attr);
+int xfs_attr_remove_iter(struct xfs_attr_intent *attr);
+bool xfs_attr_namecheck(const void *name, size_t length);
+int xfs_attr_calc_size(struct xfs_da_args *args, int *local);
+void xfs_init_attr_trans(struct xfs_da_args *args, struct xfs_trans_res *tres,
+			 unsigned int *total);
+
+/*
+ * Check to see if the attr should be upgraded from non-existent or shortform to
+ * single-leaf-block attribute list.
+ */
+static inline bool
+xfs_attr_is_shortform(
+	struct xfs_inode    *ip)
+{
+	return ip->i_af.if_format == XFS_DINODE_FMT_LOCAL ||
+	       (ip->i_af.if_format == XFS_DINODE_FMT_EXTENTS &&
+		ip->i_af.if_nextents == 0);
+}
+
+static inline enum xfs_delattr_state
+xfs_attr_init_add_state(struct xfs_da_args *args)
+{
+	/*
+	 * When called from the completion of a attr remove to determine the
+	 * next state, the attribute fork may be null. This can occur only occur
+	 * on a pure remove, but we grab the next state before we check if a
+	 * replace operation is being performed. If we are called from any other
+	 * context, i_af is guaranteed to exist. Hence if the attr fork is
+	 * null, we were called from a pure remove operation and so we are done.
+	 */
+	if (!xfs_inode_has_attr_fork(args->dp))
+		return XFS_DAS_DONE;
+
+	args->op_flags |= XFS_DA_OP_ADDNAME;
+	if (xfs_attr_is_shortform(args->dp))
+		return XFS_DAS_SF_ADD;
+	if (xfs_attr_is_leaf(args->dp))
+		return XFS_DAS_LEAF_ADD;
+	return XFS_DAS_NODE_ADD;
+}
+
+static inline enum xfs_delattr_state
+xfs_attr_init_remove_state(struct xfs_da_args *args)
+{
+	args->op_flags |= XFS_DA_OP_REMOVE;
+	if (xfs_attr_is_shortform(args->dp))
+		return XFS_DAS_SF_REMOVE;
+	if (xfs_attr_is_leaf(args->dp))
+		return XFS_DAS_LEAF_REMOVE;
+	return XFS_DAS_NODE_REMOVE;
+}
+
+/*
+ * If we are logging the attributes, then we have to start with removal of the
+ * old attribute so that there is always consistent state that we can recover
+ * from if the system goes down part way through. We always log the new attr
+ * value, so even when we remove the attr first we still have the information in
+ * the log to finish the replace operation atomically.
+ */
+static inline enum xfs_delattr_state
+xfs_attr_init_replace_state(struct xfs_da_args *args)
+{
+	args->op_flags |= XFS_DA_OP_ADDNAME | XFS_DA_OP_REPLACE;
+	if (args->op_flags & XFS_DA_OP_LOGGED)
+		return xfs_attr_init_remove_state(args);
+	return xfs_attr_init_add_state(args);
+}
+
+extern struct kmem_cache *xfs_attr_intent_cache;
+int __init xfs_attr_intent_init_cache(void);
+void xfs_attr_intent_destroy_cache(void);
+
+#endif	/* __XFS_ATTR_H__ */