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diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
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+/* 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__ */