--- /dev/null
+/*
+ * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#ifndef __XFS_ALLOC_H__
+#define __XFS_ALLOC_H__
+
+struct xfs_buf;
+struct xfs_btree_cur;
+struct xfs_mount;
+struct xfs_perag;
+struct xfs_trans;
+
+extern struct workqueue_struct *xfs_alloc_wq;
+
+/*
+ * Freespace allocation types. Argument to xfs_alloc_[v]extent.
+ */
+#define XFS_ALLOCTYPE_ANY_AG 0x01 /* allocate anywhere, use rotor */
+#define XFS_ALLOCTYPE_FIRST_AG 0x02 /* ... start at ag 0 */
+#define XFS_ALLOCTYPE_START_AG 0x04 /* anywhere, start in this a.g. */
+#define XFS_ALLOCTYPE_THIS_AG 0x08 /* anywhere in this a.g. */
+#define XFS_ALLOCTYPE_START_BNO 0x10 /* near this block else anywhere */
+#define XFS_ALLOCTYPE_NEAR_BNO 0x20 /* in this a.g. and near this block */
+#define XFS_ALLOCTYPE_THIS_BNO 0x40 /* at exactly this block */
+
+/* this should become an enum again when the tracing code is fixed */
+typedef unsigned int xfs_alloctype_t;
+
+#define XFS_ALLOC_TYPES \
+ { XFS_ALLOCTYPE_ANY_AG, "ANY_AG" }, \
+ { XFS_ALLOCTYPE_FIRST_AG, "FIRST_AG" }, \
+ { XFS_ALLOCTYPE_START_AG, "START_AG" }, \
+ { XFS_ALLOCTYPE_THIS_AG, "THIS_AG" }, \
+ { XFS_ALLOCTYPE_START_BNO, "START_BNO" }, \
+ { XFS_ALLOCTYPE_NEAR_BNO, "NEAR_BNO" }, \
+ { XFS_ALLOCTYPE_THIS_BNO, "THIS_BNO" }
+
+/*
+ * Flags for xfs_alloc_fix_freelist.
+ */
+#define XFS_ALLOC_FLAG_TRYLOCK 0x00000001 /* use trylock for buffer locking */
+#define XFS_ALLOC_FLAG_FREEING 0x00000002 /* indicate caller is freeing extents*/
+
+/*
+ * In order to avoid ENOSPC-related deadlock caused by
+ * out-of-order locking of AGF buffer (PV 947395), we place
+ * constraints on the relationship among actual allocations for
+ * data blocks, freelist blocks, and potential file data bmap
+ * btree blocks. However, these restrictions may result in no
+ * actual space allocated for a delayed extent, for example, a data
+ * block in a certain AG is allocated but there is no additional
+ * block for the additional bmap btree block due to a split of the
+ * bmap btree of the file. The result of this may lead to an
+ * infinite loop in xfssyncd when the file gets flushed to disk and
+ * all delayed extents need to be actually allocated. To get around
+ * this, we explicitly set aside a few blocks which will not be
+ * reserved in delayed allocation. Considering the minimum number of
+ * needed freelist blocks is 4 fsbs _per AG_, a potential split of file's bmap
+ * btree requires 1 fsb, so we set the number of set-aside blocks
+ * to 4 + 4*agcount.
+ */
+#define XFS_ALLOC_SET_ASIDE(mp) (4 + ((mp)->m_sb.sb_agcount * 4))
+
+/*
+ * When deciding how much space to allocate out of an AG, we limit the
+ * allocation maximum size to the size the AG. However, we cannot use all the
+ * blocks in the AG - some are permanently used by metadata. These
+ * blocks are generally:
+ * - the AG superblock, AGF, AGI and AGFL
+ * - the AGF (bno and cnt) and AGI btree root blocks
+ * - 4 blocks on the AGFL according to XFS_ALLOC_SET_ASIDE() limits
+ *
+ * The AG headers are sector sized, so the amount of space they take up is
+ * dependent on filesystem geometry. The others are all single blocks.
+ */
+#define XFS_ALLOC_AG_MAX_USABLE(mp) \
+ ((mp)->m_sb.sb_agblocks - XFS_BB_TO_FSB(mp, XFS_FSS_TO_BB(mp, 4)) - 7)
+
+
+/*
+ * Argument structure for xfs_alloc routines.
+ * This is turned into a structure to avoid having 20 arguments passed
+ * down several levels of the stack.
+ */
+typedef struct xfs_alloc_arg {
+ struct xfs_trans *tp; /* transaction pointer */
+ struct xfs_mount *mp; /* file system mount point */
+ struct xfs_buf *agbp; /* buffer for a.g. freelist header */
+ struct xfs_perag *pag; /* per-ag struct for this agno */
+ xfs_fsblock_t fsbno; /* file system block number */
+ xfs_agnumber_t agno; /* allocation group number */
+ xfs_agblock_t agbno; /* allocation group-relative block # */
+ xfs_extlen_t minlen; /* minimum size of extent */
+ xfs_extlen_t maxlen; /* maximum size of extent */
+ xfs_extlen_t mod; /* mod value for extent size */
+ xfs_extlen_t prod; /* prod value for extent size */
+ xfs_extlen_t minleft; /* min blocks must be left after us */
+ xfs_extlen_t total; /* total blocks needed in xaction */
+ xfs_extlen_t alignment; /* align answer to multiple of this */
+ xfs_extlen_t minalignslop; /* slop for minlen+alignment calcs */
+ xfs_extlen_t len; /* output: actual size of extent */
+ xfs_alloctype_t type; /* allocation type XFS_ALLOCTYPE_... */
+ xfs_alloctype_t otype; /* original allocation type */
+ char wasdel; /* set if allocation was prev delayed */
+ char wasfromfl; /* set if allocation is from freelist */
+ char isfl; /* set if is freelist blocks - !acctg */
+ char userdata; /* set if this is user data */
+ xfs_fsblock_t firstblock; /* io first block allocated */
+} xfs_alloc_arg_t;
+
+/*
+ * Defines for userdata
+ */
+#define XFS_ALLOC_USERDATA 1 /* allocation is for user data*/
+#define XFS_ALLOC_INITIAL_USER_DATA 2 /* special case start of file */
+
+/*
+ * Find the length of the longest extent in an AG.
+ */
+xfs_extlen_t
+xfs_alloc_longest_free_extent(struct xfs_mount *mp,
+ struct xfs_perag *pag);
+
+/*
+ * Compute and fill in value of m_ag_maxlevels.
+ */
+void
+xfs_alloc_compute_maxlevels(
+ struct xfs_mount *mp); /* file system mount structure */
+
+/*
+ * Get a block from the freelist.
+ * Returns with the buffer for the block gotten.
+ */
+int /* error */
+xfs_alloc_get_freelist(
+ struct xfs_trans *tp, /* transaction pointer */
+ struct xfs_buf *agbp, /* buffer containing the agf structure */
+ xfs_agblock_t *bnop, /* block address retrieved from freelist */
+ int btreeblk); /* destination is a AGF btree */
+
+/*
+ * Log the given fields from the agf structure.
+ */
+void
+xfs_alloc_log_agf(
+ struct xfs_trans *tp, /* transaction pointer */
+ struct xfs_buf *bp, /* buffer for a.g. freelist header */
+ int fields);/* mask of fields to be logged (XFS_AGF_...) */
+
+/*
+ * Interface for inode allocation to force the pag data to be initialized.
+ */
+int /* error */
+xfs_alloc_pagf_init(
+ struct xfs_mount *mp, /* file system mount structure */
+ struct xfs_trans *tp, /* transaction pointer */
+ xfs_agnumber_t agno, /* allocation group number */
+ int flags); /* XFS_ALLOC_FLAGS_... */
+
+/*
+ * Put the block on the freelist for the allocation group.
+ */
+int /* error */
+xfs_alloc_put_freelist(
+ struct xfs_trans *tp, /* transaction pointer */
+ struct xfs_buf *agbp, /* buffer for a.g. freelist header */
+ struct xfs_buf *agflbp,/* buffer for a.g. free block array */
+ xfs_agblock_t bno, /* block being freed */
+ int btreeblk); /* owner was a AGF btree */
+
+/*
+ * Read in the allocation group header (free/alloc section).
+ */
+int /* error */
+xfs_alloc_read_agf(
+ struct xfs_mount *mp, /* mount point structure */
+ struct xfs_trans *tp, /* transaction pointer */
+ xfs_agnumber_t agno, /* allocation group number */
+ int flags, /* XFS_ALLOC_FLAG_... */
+ struct xfs_buf **bpp); /* buffer for the ag freelist header */
+
+/*
+ * Allocate an extent (variable-size).
+ */
+int /* error */
+xfs_alloc_vextent(
+ xfs_alloc_arg_t *args); /* allocation argument structure */
+
+/*
+ * Free an extent.
+ */
+int /* error */
+xfs_free_extent(
+ struct xfs_trans *tp, /* transaction pointer */
+ xfs_fsblock_t bno, /* starting block number of extent */
+ xfs_extlen_t len); /* length of extent */
+
+int /* error */
+xfs_alloc_lookup_le(
+ struct xfs_btree_cur *cur, /* btree cursor */
+ xfs_agblock_t bno, /* starting block of extent */
+ xfs_extlen_t len, /* length of extent */
+ int *stat); /* success/failure */
+
+int /* error */
+xfs_alloc_lookup_ge(
+ struct xfs_btree_cur *cur, /* btree cursor */
+ xfs_agblock_t bno, /* starting block of extent */
+ xfs_extlen_t len, /* length of extent */
+ int *stat); /* success/failure */
+
+int /* error */
+xfs_alloc_get_rec(
+ struct xfs_btree_cur *cur, /* btree cursor */
+ xfs_agblock_t *bno, /* output: starting block of extent */
+ xfs_extlen_t *len, /* output: length of extent */
+ int *stat); /* output: success/failure */
+
+int xfs_read_agf(struct xfs_mount *mp, struct xfs_trans *tp,
+ xfs_agnumber_t agno, int flags, struct xfs_buf **bpp);
+
+#endif /* __XFS_ALLOC_H__ */
Code Review / kvmfornfv.git / blobdiff