// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc. * All Rights Reserved. */ #include "xfs.h" #include "xfs_fs.h" #include "xfs_format.h" #include "xfs_log_format.h" #include "xfs_shared.h" #include "xfs_trans_resv.h" #include "xfs_bit.h" #include "xfs_mount.h" #include "xfs_defer.h" #include "xfs_btree.h" #include "xfs_rmap.h" #include "xfs_alloc_btree.h" #include "xfs_alloc.h" #include "xfs_extent_busy.h" #include "xfs_errortag.h" #include "xfs_error.h" #include "xfs_trace.h" #include "xfs_trans.h" #include "xfs_buf_item.h" #include "xfs_log.h" #include "xfs_ag.h" #include "xfs_ag_resv.h" #include "xfs_bmap.h" #include "xfs_health.h" #include "xfs_extfree_item.h" struct kmem_cache *xfs_extfree_item_cache; struct workqueue_struct *xfs_alloc_wq; #define XFS_ABSDIFF(a,b) … #define XFSA_FIXUP_BNO_OK … #define XFSA_FIXUP_CNT_OK … /* * Size of the AGFL. For CRC-enabled filesystes we steal a couple of slots in * the beginning of the block for a proper header with the location information * and CRC. */ unsigned int xfs_agfl_size( struct xfs_mount *mp) { … } unsigned int xfs_refc_block( struct xfs_mount *mp) { … } xfs_extlen_t xfs_prealloc_blocks( struct xfs_mount *mp) { … } /* * The number of blocks per AG that we withhold from xfs_dec_fdblocks to * guarantee that we can refill the AGFL prior to allocating space in a nearly * full AG. Although the space described by the free space btrees, the * blocks used by the freesp btrees themselves, and the blocks owned by the * AGFL are counted in the ondisk fdblocks, it's a mistake to let the ondisk * free space in the AG drop so low that the free space btrees cannot refill an * empty AGFL up to the minimum level. Rather than grind through empty AGs * until the fs goes down, we subtract this many AG blocks from the incore * fdblocks to ensure user allocation does not overcommit the space the * filesystem needs for the AGFLs. The rmap btree uses a per-AG reservation to * withhold space from xfs_dec_fdblocks, so we do not account for that here. */ #define XFS_ALLOCBT_AGFL_RESERVE … /* * Compute the number of blocks that we set aside to guarantee the ability to * refill the AGFL and handle a full bmap btree split. * * 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 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. * * For each AG, we need to reserve enough blocks to replenish a totally empty * AGFL and 4 more to handle a potential split of the file's bmap btree. */ unsigned int xfs_alloc_set_aside( struct xfs_mount *mp) { … } /* * 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, and optionally * the AGI free inode and rmap btree root blocks. * - blocks on the AGFL according to xfs_alloc_set_aside() limits * - the rmapbt root block * * 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. */ unsigned int xfs_alloc_ag_max_usable( struct xfs_mount *mp) { … } static int xfs_alloc_lookup( struct xfs_btree_cur *cur, xfs_lookup_t dir, xfs_agblock_t bno, xfs_extlen_t len, int *stat) { … } /* * Lookup the record equal to [bno, len] in the btree given by cur. */ static inline int /* error */ xfs_alloc_lookup_eq( 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 */ { … } /* * Lookup the first record greater than or equal to [bno, len] * in the btree given by cur. */ 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 */ { … } /* * Lookup the first record less than or equal to [bno, len] * in the btree given by cur. */ 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 */ { … } static inline bool xfs_alloc_cur_active( struct xfs_btree_cur *cur) { … } /* * Update the record referred to by cur to the value given * by [bno, len]. * This either works (return 0) or gets an EFSCORRUPTED error. */ STATIC int /* error */ xfs_alloc_update( struct xfs_btree_cur *cur, /* btree cursor */ xfs_agblock_t bno, /* starting block of extent */ xfs_extlen_t len) /* length of extent */ { … } /* Convert the ondisk btree record to its incore representation. */ void xfs_alloc_btrec_to_irec( const union xfs_btree_rec *rec, struct xfs_alloc_rec_incore *irec) { … } /* Simple checks for free space records. */ xfs_failaddr_t xfs_alloc_check_irec( struct xfs_perag *pag, const struct xfs_alloc_rec_incore *irec) { … } static inline int xfs_alloc_complain_bad_rec( struct xfs_btree_cur *cur, xfs_failaddr_t fa, const struct xfs_alloc_rec_incore *irec) { … } /* * Get the data from the pointed-to record. */ 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 */ { … } /* * Compute aligned version of the found extent. * Takes alignment and min length into account. */ STATIC bool xfs_alloc_compute_aligned( xfs_alloc_arg_t *args, /* allocation argument structure */ xfs_agblock_t foundbno, /* starting block in found extent */ xfs_extlen_t foundlen, /* length in found extent */ xfs_agblock_t *resbno, /* result block number */ xfs_extlen_t *reslen, /* result length */ unsigned *busy_gen) { … } /* * Compute best start block and diff for "near" allocations. * freelen >= wantlen already checked by caller. */ STATIC xfs_extlen_t /* difference value (absolute) */ xfs_alloc_compute_diff( xfs_agblock_t wantbno, /* target starting block */ xfs_extlen_t wantlen, /* target length */ xfs_extlen_t alignment, /* target alignment */ int datatype, /* are we allocating data? */ xfs_agblock_t freebno, /* freespace's starting block */ xfs_extlen_t freelen, /* freespace's length */ xfs_agblock_t *newbnop) /* result: best start block from free */ { … } /* * Fix up the length, based on mod and prod. * len should be k * prod + mod for some k. * If len is too small it is returned unchanged. * If len hits maxlen it is left alone. */ STATIC void xfs_alloc_fix_len( xfs_alloc_arg_t *args) /* allocation argument structure */ { … } /* * Determine if the cursor points to the block that contains the right-most * block of records in the by-count btree. This block contains the largest * contiguous free extent in the AG, so if we modify a record in this block we * need to call xfs_alloc_fixup_longest() once the modifications are done to * ensure the agf->agf_longest field is kept up to date with the longest free * extent tracked by the by-count btree. */ static bool xfs_alloc_cursor_at_lastrec( struct xfs_btree_cur *cnt_cur) { … } /* * Find the rightmost record of the cntbt, and return the longest free space * recorded in it. Simply set both the block number and the length to their * maximum values before searching. */ static int xfs_cntbt_longest( struct xfs_btree_cur *cnt_cur, xfs_extlen_t *longest) { … } /* * Update the longest contiguous free extent in the AG from the by-count cursor * that is passed to us. This should be done at the end of any allocation or * freeing operation that touches the longest extent in the btree. * * Needing to update the longest extent can be determined by calling * xfs_alloc_cursor_at_lastrec() after the cursor is positioned for record * modification but before the modification begins. */ static int xfs_alloc_fixup_longest( struct xfs_btree_cur *cnt_cur) { … } /* * Update the two btrees, logically removing from freespace the extent * starting at rbno, rlen blocks. The extent is contained within the * actual (current) free extent fbno for flen blocks. * Flags are passed in indicating whether the cursors are set to the * relevant records. */ STATIC int /* error code */ xfs_alloc_fixup_trees( struct xfs_btree_cur *cnt_cur, /* cursor for by-size btree */ struct xfs_btree_cur *bno_cur, /* cursor for by-block btree */ xfs_agblock_t fbno, /* starting block of free extent */ xfs_extlen_t flen, /* length of free extent */ xfs_agblock_t rbno, /* starting block of returned extent */ xfs_extlen_t rlen, /* length of returned extent */ int flags) /* flags, XFSA_FIXUP_... */ { … } /* * We do not verify the AGFL contents against AGF-based index counters here, * even though we may have access to the perag that contains shadow copies. We * don't know if the AGF based counters have been checked, and if they have they * still may be inconsistent because they haven't yet been reset on the first * allocation after the AGF has been read in. * * This means we can only check that all agfl entries contain valid or null * values because we can't reliably determine the active range to exclude * NULLAGBNO as a valid value. * * However, we can't even do that for v4 format filesystems because there are * old versions of mkfs out there that does not initialise the AGFL to known, * verifiable values. HEnce we can't tell the difference between a AGFL block * allocated by mkfs and a corrupted AGFL block here on v4 filesystems. * * As a result, we can only fully validate AGFL block numbers when we pull them * from the freelist in xfs_alloc_get_freelist(). */ static xfs_failaddr_t xfs_agfl_verify( struct xfs_buf *bp) { … } static void xfs_agfl_read_verify( struct xfs_buf *bp) { … } static void xfs_agfl_write_verify( struct xfs_buf *bp) { … } const struct xfs_buf_ops xfs_agfl_buf_ops = …; /* * Read in the allocation group free block array. */ int xfs_alloc_read_agfl( struct xfs_perag *pag, struct xfs_trans *tp, struct xfs_buf **bpp) { … } STATIC int xfs_alloc_update_counters( struct xfs_trans *tp, struct xfs_buf *agbp, long len) { … } /* * Block allocation algorithm and data structures. */ struct xfs_alloc_cur { … }; /* * Set up cursors, etc. in the extent allocation cursor. This function can be * called multiple times to reset an initialized structure without having to * reallocate cursors. */ static int xfs_alloc_cur_setup( struct xfs_alloc_arg *args, struct xfs_alloc_cur *acur) { … } static void xfs_alloc_cur_close( struct xfs_alloc_cur *acur, bool error) { … } /* * Check an extent for allocation and track the best available candidate in the * allocation structure. The cursor is deactivated if it has entered an out of * range state based on allocation arguments. Optionally return the extent * extent geometry and allocation status if requested by the caller. */ static int xfs_alloc_cur_check( struct xfs_alloc_arg *args, struct xfs_alloc_cur *acur, struct xfs_btree_cur *cur, int *new) { … } /* * Complete an allocation of a candidate extent. Remove the extent from both * trees and update the args structure. */ STATIC int xfs_alloc_cur_finish( struct xfs_alloc_arg *args, struct xfs_alloc_cur *acur) { … } /* * Locality allocation lookup algorithm. This expects a cntbt cursor and uses * bno optimized lookup to search for extents with ideal size and locality. */ STATIC int xfs_alloc_cntbt_iter( struct xfs_alloc_arg *args, struct xfs_alloc_cur *acur) { … } /* * Deal with the case where only small freespaces remain. Either return the * contents of the last freespace record, or allocate space from the freelist if * there is nothing in the tree. */ STATIC int /* error */ xfs_alloc_ag_vextent_small( struct xfs_alloc_arg *args, /* allocation argument structure */ struct xfs_btree_cur *ccur, /* optional by-size cursor */ xfs_agblock_t *fbnop, /* result block number */ xfs_extlen_t *flenp, /* result length */ int *stat) /* status: 0-freelist, 1-normal/none */ { … } /* * Allocate a variable extent at exactly agno/bno. * Extent's length (returned in *len) will be between minlen and maxlen, * and of the form k * prod + mod unless there's nothing that large. * Return the starting a.g. block (bno), or NULLAGBLOCK if we can't do it. */ STATIC int /* error */ xfs_alloc_ag_vextent_exact( xfs_alloc_arg_t *args) /* allocation argument structure */ { … } /* * Search a given number of btree records in a given direction. Check each * record against the good extent we've already found. */ STATIC int xfs_alloc_walk_iter( struct xfs_alloc_arg *args, struct xfs_alloc_cur *acur, struct xfs_btree_cur *cur, bool increment, bool find_one, /* quit on first candidate */ int count, /* rec count (-1 for infinite) */ int *stat) { … } /* * Search the by-bno and by-size btrees in parallel in search of an extent with * ideal locality based on the NEAR mode ->agbno locality hint. */ STATIC int xfs_alloc_ag_vextent_locality( struct xfs_alloc_arg *args, struct xfs_alloc_cur *acur, int *stat) { … } /* Check the last block of the cnt btree for allocations. */ static int xfs_alloc_ag_vextent_lastblock( struct xfs_alloc_arg *args, struct xfs_alloc_cur *acur, xfs_agblock_t *bno, xfs_extlen_t *len, bool *allocated) { … } /* * Allocate a variable extent near bno in the allocation group agno. * Extent's length (returned in len) will be between minlen and maxlen, * and of the form k * prod + mod unless there's nothing that large. * Return the starting a.g. block, or NULLAGBLOCK if we can't do it. */ STATIC int xfs_alloc_ag_vextent_near( struct xfs_alloc_arg *args, uint32_t alloc_flags) { … } /* * Allocate a variable extent anywhere in the allocation group agno. * Extent's length (returned in len) will be between minlen and maxlen, * and of the form k * prod + mod unless there's nothing that large. * Return the starting a.g. block, or NULLAGBLOCK if we can't do it. */ static int xfs_alloc_ag_vextent_size( struct xfs_alloc_arg *args, uint32_t alloc_flags) { … } /* * Free the extent starting at agno/bno for length. */ int xfs_free_ag_extent( struct xfs_trans *tp, struct xfs_buf *agbp, xfs_agnumber_t agno, xfs_agblock_t bno, xfs_extlen_t len, const struct xfs_owner_info *oinfo, enum xfs_ag_resv_type type) { … } /* * Visible (exported) allocation/free functions. * Some of these are used just by xfs_alloc_btree.c and this file. */ /* * Compute and fill in value of m_alloc_maxlevels. */ void xfs_alloc_compute_maxlevels( xfs_mount_t *mp) /* file system mount structure */ { … } /* * Find the length of the longest extent in an AG. The 'need' parameter * specifies how much space we're going to need for the AGFL and the * 'reserved' parameter tells us how many blocks in this AG are reserved for * other callers. */ xfs_extlen_t xfs_alloc_longest_free_extent( struct xfs_perag *pag, xfs_extlen_t need, xfs_extlen_t reserved) { … } /* * Compute the minimum length of the AGFL in the given AG. If @pag is NULL, * return the largest possible minimum length. */ unsigned int xfs_alloc_min_freelist( struct xfs_mount *mp, struct xfs_perag *pag) { … } /* * Check if the operation we are fixing up the freelist for should go ahead or * not. If we are freeing blocks, we always allow it, otherwise the allocation * is dependent on whether the size and shape of free space available will * permit the requested allocation to take place. */ static bool xfs_alloc_space_available( struct xfs_alloc_arg *args, xfs_extlen_t min_free, int flags) { … } /* * Check the agfl fields of the agf for inconsistency or corruption. * * The original purpose was to detect an agfl header padding mismatch between * current and early v5 kernels. This problem manifests as a 1-slot size * difference between the on-disk flcount and the active [first, last] range of * a wrapped agfl. * * However, we need to use these same checks to catch agfl count corruptions * unrelated to padding. This could occur on any v4 or v5 filesystem, so either * way, we need to reset the agfl and warn the user. * * Return true if a reset is required before the agfl can be used, false * otherwise. */ static bool xfs_agfl_needs_reset( struct xfs_mount *mp, struct xfs_agf *agf) { … } /* * Reset the agfl to an empty state. Ignore/drop any existing blocks since the * agfl content cannot be trusted. Warn the user that a repair is required to * recover leaked blocks. * * The purpose of this mechanism is to handle filesystems affected by the agfl * header padding mismatch problem. A reset keeps the filesystem online with a * relatively minor free space accounting inconsistency rather than suffer the * inevitable crash from use of an invalid agfl block. */ static void xfs_agfl_reset( struct xfs_trans *tp, struct xfs_buf *agbp, struct xfs_perag *pag) { … } /* * Add the extent to the list of extents to be free at transaction end. * The list is maintained sorted (by block number). */ static int xfs_defer_extent_free( struct xfs_trans *tp, xfs_fsblock_t bno, xfs_filblks_t len, const struct xfs_owner_info *oinfo, enum xfs_ag_resv_type type, unsigned int free_flags, struct xfs_defer_pending **dfpp) { … } int xfs_free_extent_later( struct xfs_trans *tp, xfs_fsblock_t bno, xfs_filblks_t len, const struct xfs_owner_info *oinfo, enum xfs_ag_resv_type type, unsigned int free_flags) { … } /* * Set up automatic freeing of unwritten space in the filesystem. * * This function attached a paused deferred extent free item to the * transaction. Pausing means that the EFI will be logged in the next * transaction commit, but the pending EFI will not be finished until the * pending item is unpaused. * * If the system goes down after the EFI has been persisted to the log but * before the pending item is unpaused, log recovery will find the EFI, fail to * find the EFD, and free the space. * * If the pending item is unpaused, the next transaction commit will log an EFD * without freeing the space. * * Caller must ensure that the tp, fsbno, len, oinfo, and resv flags of the * @args structure are set to the relevant values. */ int xfs_alloc_schedule_autoreap( const struct xfs_alloc_arg *args, unsigned int free_flags, struct xfs_alloc_autoreap *aarp) { … } /* * Cancel automatic freeing of unwritten space in the filesystem. * * Earlier, we created a paused deferred extent free item and attached it to * this transaction so that we could automatically roll back a new space * allocation if the system went down. Now we want to cancel the paused work * item by marking the EFI stale so we don't actually free the space, unpausing * the pending item and logging an EFD. * * The caller generally should have already mapped the space into the ondisk * filesystem. If the reserved space was partially used, the caller must call * xfs_free_extent_later to create a new EFI to free the unused space. */ void xfs_alloc_cancel_autoreap( struct xfs_trans *tp, struct xfs_alloc_autoreap *aarp) { … } /* * Commit automatic freeing of unwritten space in the filesystem. * * This unpauses an earlier _schedule_autoreap and commits to freeing the * allocated space. Call this if none of the reserved space was used. */ void xfs_alloc_commit_autoreap( struct xfs_trans *tp, struct xfs_alloc_autoreap *aarp) { … } #ifdef DEBUG /* * Check if an AGF has a free extent record whose length is equal to * args->minlen. */ STATIC int xfs_exact_minlen_extent_available( struct xfs_alloc_arg *args, struct xfs_buf *agbp, int *stat) { … } #endif /* * Decide whether to use this allocation group for this allocation. * If so, fix up the btree freelist's size. */ int /* error */ xfs_alloc_fix_freelist( struct xfs_alloc_arg *args, /* allocation argument structure */ uint32_t alloc_flags) { … } /* * Get a block from the freelist. * Returns with the buffer for the block gotten. */ int xfs_alloc_get_freelist( struct xfs_perag *pag, struct xfs_trans *tp, struct xfs_buf *agbp, xfs_agblock_t *bnop, int btreeblk) { … } /* * Log the given fields from the agf structure. */ void xfs_alloc_log_agf( struct xfs_trans *tp, struct xfs_buf *bp, uint32_t fields) { … } /* * Put the block on the freelist for the allocation group. */ int xfs_alloc_put_freelist( struct xfs_perag *pag, struct xfs_trans *tp, struct xfs_buf *agbp, struct xfs_buf *agflbp, xfs_agblock_t bno, int btreeblk) { … } /* * Check that this AGF/AGI header's sequence number and length matches the AG * number and size in fsblocks. */ xfs_failaddr_t xfs_validate_ag_length( struct xfs_buf *bp, uint32_t seqno, uint32_t length) { … } /* * Verify the AGF is consistent. * * We do not verify the AGFL indexes in the AGF are fully consistent here * because of issues with variable on-disk structure sizes. Instead, we check * the agfl indexes for consistency when we initialise the perag from the AGF * information after a read completes. * * If the index is inconsistent, then we mark the perag as needing an AGFL * reset. The first AGFL update performed then resets the AGFL indexes and * refills the AGFL with known good free blocks, allowing the filesystem to * continue operating normally at the cost of a few leaked free space blocks. */ static xfs_failaddr_t xfs_agf_verify( struct xfs_buf *bp) { … } static void xfs_agf_read_verify( struct xfs_buf *bp) { … } static void xfs_agf_write_verify( struct xfs_buf *bp) { … } const struct xfs_buf_ops xfs_agf_buf_ops = …; /* * Read in the allocation group header (free/alloc section). */ int xfs_read_agf( struct xfs_perag *pag, struct xfs_trans *tp, int flags, struct xfs_buf **agfbpp) { … } /* * Read in the allocation group header (free/alloc section) and initialise the * perag structure if necessary. If the caller provides @agfbpp, then return the * locked buffer to the caller, otherwise free it. */ int xfs_alloc_read_agf( struct xfs_perag *pag, struct xfs_trans *tp, int flags, struct xfs_buf **agfbpp) { … } /* * Pre-proces allocation arguments to set initial state that we don't require * callers to set up correctly, as well as bounds check the allocation args * that are set up. */ static int xfs_alloc_vextent_check_args( struct xfs_alloc_arg *args, xfs_fsblock_t target, xfs_agnumber_t *minimum_agno) { … } /* * Prepare an AG for allocation. If the AG is not prepared to accept the * allocation, return failure. * * XXX(dgc): The complexity of "need_pag" will go away as all caller paths are * modified to hold their own perag references. */ static int xfs_alloc_vextent_prepare_ag( struct xfs_alloc_arg *args, uint32_t alloc_flags) { … } /* * Post-process allocation results to account for the allocation if it succeed * and set the allocated block number correctly for the caller. * * XXX: we should really be returning ENOSPC for ENOSPC, not * hiding it behind a "successful" NULLFSBLOCK allocation. */ static int xfs_alloc_vextent_finish( struct xfs_alloc_arg *args, xfs_agnumber_t minimum_agno, int alloc_error, bool drop_perag) { … } /* * Allocate within a single AG only. This uses a best-fit length algorithm so if * you need an exact sized allocation without locality constraints, this is the * fastest way to do it. * * Caller is expected to hold a perag reference in args->pag. */ int xfs_alloc_vextent_this_ag( struct xfs_alloc_arg *args, xfs_agnumber_t agno) { … } /* * Iterate all AGs trying to allocate an extent starting from @start_ag. * * If the incoming allocation type is XFS_ALLOCTYPE_NEAR_BNO, it means the * allocation attempts in @start_agno have locality information. If we fail to * allocate in that AG, then we revert to anywhere-in-AG for all the other AGs * we attempt to allocation in as there is no locality optimisation possible for * those allocations. * * On return, args->pag may be left referenced if we finish before the "all * failed" return point. The allocation finish still needs the perag, and * so the caller will release it once they've finished the allocation. * * When we wrap the AG iteration at the end of the filesystem, we have to be * careful not to wrap into AGs below ones we already have locked in the * transaction if we are doing a blocking iteration. This will result in an * out-of-order locking of AGFs and hence can cause deadlocks. */ static int xfs_alloc_vextent_iterate_ags( struct xfs_alloc_arg *args, xfs_agnumber_t minimum_agno, xfs_agnumber_t start_agno, xfs_agblock_t target_agbno, uint32_t alloc_flags) { … } /* * Iterate from the AGs from the start AG to the end of the filesystem, trying * to allocate blocks. It starts with a near allocation attempt in the initial * AG, then falls back to anywhere-in-ag after the first AG fails. It will wrap * back to zero if allowed by previous allocations in this transaction, * otherwise will wrap back to the start AG and run a second blocking pass to * the end of the filesystem. */ int xfs_alloc_vextent_start_ag( struct xfs_alloc_arg *args, xfs_fsblock_t target) { … } /* * Iterate from the agno indicated via @target through to the end of the * filesystem attempting blocking allocation. This does not wrap or try a second * pass, so will not recurse into AGs lower than indicated by the target. */ int xfs_alloc_vextent_first_ag( struct xfs_alloc_arg *args, xfs_fsblock_t target) { … } /* * Allocate at the exact block target or fail. Caller is expected to hold a * perag reference in args->pag. */ int xfs_alloc_vextent_exact_bno( struct xfs_alloc_arg *args, xfs_fsblock_t target) { … } /* * Allocate an extent as close to the target as possible. If there are not * viable candidates in the AG, then fail the allocation. * * Caller may or may not have a per-ag reference in args->pag. */ int xfs_alloc_vextent_near_bno( struct xfs_alloc_arg *args, xfs_fsblock_t target) { … } /* Ensure that the freelist is at full capacity. */ int xfs_free_extent_fix_freelist( struct xfs_trans *tp, struct xfs_perag *pag, struct xfs_buf **agbp) { … } /* * Free an extent. * Just break up the extent address and hand off to xfs_free_ag_extent * after fixing up the freelist. */ int __xfs_free_extent( struct xfs_trans *tp, struct xfs_perag *pag, xfs_agblock_t agbno, xfs_extlen_t len, const struct xfs_owner_info *oinfo, enum xfs_ag_resv_type type, bool skip_discard) { … } struct xfs_alloc_query_range_info { … }; /* Format btree record and pass to our callback. */ STATIC int xfs_alloc_query_range_helper( struct xfs_btree_cur *cur, const union xfs_btree_rec *rec, void *priv) { … } /* Find all free space within a given range of blocks. */ int xfs_alloc_query_range( struct xfs_btree_cur *cur, const struct xfs_alloc_rec_incore *low_rec, const struct xfs_alloc_rec_incore *high_rec, xfs_alloc_query_range_fn fn, void *priv) { … } /* Find all free space records. */ int xfs_alloc_query_all( struct xfs_btree_cur *cur, xfs_alloc_query_range_fn fn, void *priv) { … } /* * Scan part of the keyspace of the free space and tell us if the area has no * records, is fully mapped by records, or is partially filled. */ int xfs_alloc_has_records( struct xfs_btree_cur *cur, xfs_agblock_t bno, xfs_extlen_t len, enum xbtree_recpacking *outcome) { … } /* * Walk all the blocks in the AGFL. The @walk_fn can return any negative * error code or XFS_ITER_*. */ int xfs_agfl_walk( struct xfs_mount *mp, struct xfs_agf *agf, struct xfs_buf *agflbp, xfs_agfl_walk_fn walk_fn, void *priv) { … } int __init xfs_extfree_intent_init_cache(void) { … } void xfs_extfree_intent_destroy_cache(void) { … }
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