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Diffstat (limited to 'fs/xfs/xfs_buf_item.c')
| -rw-r--r-- | fs/xfs/xfs_buf_item.c | 1221 |
1 files changed, 1221 insertions, 0 deletions
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c new file mode 100644 index 0000000..9ab0039 --- /dev/null +++ b/fs/xfs/xfs_buf_item.c @@ -0,0 +1,1221 @@ +/* + * Copyright (c) 2000-2004 Silicon Graphics, Inc. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2 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. + * + * Further, this software is distributed without any warranty that it is + * free of the rightful claim of any third person regarding infringement + * or the like. Any license provided herein, whether implied or + * otherwise, applies only to this software file. Patent licenses, if + * any, provided herein do not apply to combinations of this program with + * other software, or any other product whatsoever. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write the Free Software Foundation, Inc., 59 + * Temple Place - Suite 330, Boston MA 02111-1307, USA. + * + * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy, + * Mountain View, CA 94043, or: + * + * http://www.sgi.com + * + * For further information regarding this notice, see: + * + * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/ + */ + +/* + * This file contains the implementation of the xfs_buf_log_item. + * It contains the item operations used to manipulate the buf log + * items as well as utility routines used by the buffer specific + * transaction routines. + */ + +#include "xfs.h" + +#include "xfs_macros.h" +#include "xfs_types.h" +#include "xfs_inum.h" +#include "xfs_log.h" +#include "xfs_trans.h" +#include "xfs_buf_item.h" +#include "xfs_sb.h" +#include "xfs_dir.h" +#include "xfs_dmapi.h" +#include "xfs_mount.h" +#include "xfs_trans_priv.h" +#include "xfs_rw.h" +#include "xfs_bit.h" +#include "xfs_error.h" + + +kmem_zone_t *xfs_buf_item_zone; + +#ifdef XFS_TRANS_DEBUG +/* + * This function uses an alternate strategy for tracking the bytes + * that the user requests to be logged. This can then be used + * in conjunction with the bli_orig array in the buf log item to + * catch bugs in our callers' code. + * + * We also double check the bits set in xfs_buf_item_log using a + * simple algorithm to check that every byte is accounted for. + */ +STATIC void +xfs_buf_item_log_debug( + xfs_buf_log_item_t *bip, + uint first, + uint last) +{ + uint x; + uint byte; + uint nbytes; + uint chunk_num; + uint word_num; + uint bit_num; + uint bit_set; + uint *wordp; + + ASSERT(bip->bli_logged != NULL); + byte = first; + nbytes = last - first + 1; + bfset(bip->bli_logged, first, nbytes); + for (x = 0; x < nbytes; x++) { + chunk_num = byte >> XFS_BLI_SHIFT; + word_num = chunk_num >> BIT_TO_WORD_SHIFT; + bit_num = chunk_num & (NBWORD - 1); + wordp = &(bip->bli_format.blf_data_map[word_num]); + bit_set = *wordp & (1 << bit_num); + ASSERT(bit_set); + byte++; + } +} + +/* + * This function is called when we flush something into a buffer without + * logging it. This happens for things like inodes which are logged + * separately from the buffer. + */ +void +xfs_buf_item_flush_log_debug( + xfs_buf_t *bp, + uint first, + uint last) +{ + xfs_buf_log_item_t *bip; + uint nbytes; + + bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t*); + if ((bip == NULL) || (bip->bli_item.li_type != XFS_LI_BUF)) { + return; + } + + ASSERT(bip->bli_logged != NULL); + nbytes = last - first + 1; + bfset(bip->bli_logged, first, nbytes); +} + +/* + * This function is called to verify that our caller's have logged + * all the bytes that they changed. + * + * It does this by comparing the original copy of the buffer stored in + * the buf log item's bli_orig array to the current copy of the buffer + * and ensuring that all bytes which miscompare are set in the bli_logged + * array of the buf log item. + */ +STATIC void +xfs_buf_item_log_check( + xfs_buf_log_item_t *bip) +{ + char *orig; + char *buffer; + int x; + xfs_buf_t *bp; + + ASSERT(bip->bli_orig != NULL); + ASSERT(bip->bli_logged != NULL); + + bp = bip->bli_buf; + ASSERT(XFS_BUF_COUNT(bp) > 0); + ASSERT(XFS_BUF_PTR(bp) != NULL); + orig = bip->bli_orig; + buffer = XFS_BUF_PTR(bp); + for (x = 0; x < XFS_BUF_COUNT(bp); x++) { + if (orig[x] != buffer[x] && !btst(bip->bli_logged, x)) + cmn_err(CE_PANIC, + "xfs_buf_item_log_check bip %x buffer %x orig %x index %d", + bip, bp, orig, x); + } +} +#else +#define xfs_buf_item_log_debug(x,y,z) +#define xfs_buf_item_log_check(x) +#endif + +STATIC void xfs_buf_error_relse(xfs_buf_t *bp); +STATIC void xfs_buf_do_callbacks(xfs_buf_t *bp, xfs_log_item_t *lip); + +/* + * This returns the number of log iovecs needed to log the + * given buf log item. + * + * It calculates this as 1 iovec for the buf log format structure + * and 1 for each stretch of non-contiguous chunks to be logged. + * Contiguous chunks are logged in a single iovec. + * + * If the XFS_BLI_STALE flag has been set, then log nothing. + */ +uint +xfs_buf_item_size( + xfs_buf_log_item_t *bip) +{ + uint nvecs; + int next_bit; + int last_bit; + xfs_buf_t *bp; + + ASSERT(atomic_read(&bip->bli_refcount) > 0); + if (bip->bli_flags & XFS_BLI_STALE) { + /* + * The buffer is stale, so all we need to log + * is the buf log format structure with the + * cancel flag in it. + */ + xfs_buf_item_trace("SIZE STALE", bip); + ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL); + return 1; + } + + bp = bip->bli_buf; + ASSERT(bip->bli_flags & XFS_BLI_LOGGED); + nvecs = 1; + last_bit = xfs_next_bit(bip->bli_format.blf_data_map, + bip->bli_format.blf_map_size, 0); + ASSERT(last_bit != -1); + nvecs++; + while (last_bit != -1) { + /* + * This takes the bit number to start looking from and + * returns the next set bit from there. It returns -1 + * if there are no more bits set or the start bit is + * beyond the end of the bitmap. + */ + next_bit = xfs_next_bit(bip->bli_format.blf_data_map, + bip->bli_format.blf_map_size, + last_bit + 1); + /* + * If we run out of bits, leave the loop, + * else if we find a new set of bits bump the number of vecs, + * else keep scanning the current set of bits. + */ + if (next_bit == -1) { + last_bit = -1; + } else if (next_bit != last_bit + 1) { + last_bit = next_bit; + nvecs++; + } else if (xfs_buf_offset(bp, next_bit * XFS_BLI_CHUNK) != + (xfs_buf_offset(bp, last_bit * XFS_BLI_CHUNK) + + XFS_BLI_CHUNK)) { + last_bit = next_bit; + nvecs++; + } else { + last_bit++; + } + } + + xfs_buf_item_trace("SIZE NORM", bip); + return nvecs; +} + +/* + * This is called to fill in the vector of log iovecs for the + * given log buf item. It fills the first entry with a buf log + * format structure, and the rest point to contiguous chunks + * within the buffer. + */ +void +xfs_buf_item_format( + xfs_buf_log_item_t *bip, + xfs_log_iovec_t *log_vector) +{ + uint base_size; + uint nvecs; + xfs_log_iovec_t *vecp; + xfs_buf_t *bp; + int first_bit; + int last_bit; + int next_bit; + uint nbits; + uint buffer_offset; + + ASSERT(atomic_read(&bip->bli_refcount) > 0); + ASSERT((bip->bli_flags & XFS_BLI_LOGGED) || + (bip->bli_flags & XFS_BLI_STALE)); + bp = bip->bli_buf; + ASSERT(XFS_BUF_BP_ISMAPPED(bp)); + vecp = log_vector; + + /* + * The size of the base structure is the size of the + * declared structure plus the space for the extra words + * of the bitmap. We subtract one from the map size, because + * the first element of the bitmap is accounted for in the + * size of the base structure. + */ + base_size = + (uint)(sizeof(xfs_buf_log_format_t) + + ((bip->bli_format.blf_map_size - 1) * sizeof(uint))); + vecp->i_addr = (xfs_caddr_t)&bip->bli_format; + vecp->i_len = base_size; + vecp++; + nvecs = 1; + + if (bip->bli_flags & XFS_BLI_STALE) { + /* + * The buffer is stale, so all we need to log + * is the buf log format structure with the + * cancel flag in it. + */ + xfs_buf_item_trace("FORMAT STALE", bip); + ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL); + bip->bli_format.blf_size = nvecs; + return; + } + + /* + * Fill in an iovec for each set of contiguous chunks. + */ + first_bit = xfs_next_bit(bip->bli_format.blf_data_map, + bip->bli_format.blf_map_size, 0); + ASSERT(first_bit != -1); + last_bit = first_bit; + nbits = 1; + for (;;) { + /* + * This takes the bit number to start looking from and + * returns the next set bit from there. It returns -1 + * if there are no more bits set or the start bit is + * beyond the end of the bitmap. + */ + next_bit = xfs_next_bit(bip->bli_format.blf_data_map, + bip->bli_format.blf_map_size, + (uint)last_bit + 1); + /* + * If we run out of bits fill in the last iovec and get + * out of the loop. + * Else if we start a new set of bits then fill in the + * iovec for the series we were looking at and start + * counting the bits in the new one. + * Else we're still in the same set of bits so just + * keep counting and scanning. + */ + if (next_bit == -1) { + buffer_offset = first_bit * XFS_BLI_CHUNK; + vecp->i_addr = xfs_buf_offset(bp, buffer_offset); + vecp->i_len = nbits * XFS_BLI_CHUNK; + nvecs++; + break; + } else if (next_bit != last_bit + 1) { + buffer_offset = first_bit * XFS_BLI_CHUNK; + vecp->i_addr = xfs_buf_offset(bp, buffer_offset); + vecp->i_len = nbits * XFS_BLI_CHUNK; + nvecs++; + vecp++; + first_bit = next_bit; + last_bit = next_bit; + nbits = 1; + } else if (xfs_buf_offset(bp, next_bit << XFS_BLI_SHIFT) != + (xfs_buf_offset(bp, last_bit << XFS_BLI_SHIFT) + + XFS_BLI_CHUNK)) { + buffer_offset = first_bit * XFS_BLI_CHUNK; + vecp->i_addr = xfs_buf_offset(bp, buffer_offset); + vecp->i_len = nbits * XFS_BLI_CHUNK; +/* You would think we need to bump the nvecs here too, but we do not + * this number is used by recovery, and it gets confused by the boundary + * split here + * nvecs++; + */ + vecp++; + first_bit = next_bit; + last_bit = next_bit; + nbits = 1; + } else { + last_bit++; + nbits++; + } + } + bip->bli_format.blf_size = nvecs; + + /* + * Check to make sure everything is consistent. + */ + xfs_buf_item_trace("FORMAT NORM", bip); + xfs_buf_item_log_check(bip); +} + +/* + * This is called to pin the buffer associated with the buf log + * item in memory so it cannot be written out. Simply call bpin() + * on the buffer to do this. + */ +void +xfs_buf_item_pin( + xfs_buf_log_item_t *bip) +{ + xfs_buf_t *bp; + + bp = bip->bli_buf; + ASSERT(XFS_BUF_ISBUSY(bp)); + ASSERT(atomic_read(&bip->bli_refcount) > 0); + ASSERT((bip->bli_flags & XFS_BLI_LOGGED) || + (bip->bli_flags & XFS_BLI_STALE)); + xfs_buf_item_trace("PIN", bip); + xfs_buftrace("XFS_PIN", bp); + xfs_bpin(bp); +} + + +/* + * This is called to unpin the buffer associated with the buf log + * item which was previously pinned with a call to xfs_buf_item_pin(). + * Just call bunpin() on the buffer to do this. + * + * Also drop the reference to the buf item for the current transaction. + * If the XFS_BLI_STALE flag is set and we are the last reference, + * then free up the buf log item and unlock the buffer. + */ +void +xfs_buf_item_unpin( + xfs_buf_log_item_t *bip, + int stale) +{ + xfs_mount_t *mp; + xfs_buf_t *bp; + int freed; + SPLDECL(s); + + bp = bip->bli_buf; + ASSERT(bp != NULL); + ASSERT(XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *) == bip); + ASSERT(atomic_read(&bip->bli_refcount) > 0); + xfs_buf_item_trace("UNPIN", bip); + xfs_buftrace("XFS_UNPIN", bp); + + freed = atomic_dec_and_test(&bip->bli_refcount); + mp = bip->bli_item.li_mountp; + xfs_bunpin(bp); + if (freed && stale) { + ASSERT(bip->bli_flags & XFS_BLI_STALE); + ASSERT(XFS_BUF_VALUSEMA(bp) <= 0); + ASSERT(!(XFS_BUF_ISDELAYWRITE(bp))); + ASSERT(XFS_BUF_ISSTALE(bp)); + ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL); + xfs_buf_item_trace("UNPIN STALE", bip); + xfs_buftrace("XFS_UNPIN STALE", bp); + /* + * If we get called here because of an IO error, we may + * or may not have the item on the AIL. xfs_trans_delete_ail() + * will take care of that situation. + * xfs_trans_delete_ail() drops the AIL lock. + */ + if (bip->bli_flags & XFS_BLI_STALE_INODE) { + xfs_buf_do_callbacks(bp, (xfs_log_item_t *)bip); + XFS_BUF_SET_FSPRIVATE(bp, NULL); + XFS_BUF_CLR_IODONE_FUNC(bp); + } else { + AIL_LOCK(mp,s); + xfs_trans_delete_ail(mp, (xfs_log_item_t *)bip, s); + xfs_buf_item_relse(bp); + ASSERT(XFS_BUF_FSPRIVATE(bp, void *) == NULL); + } + xfs_buf_relse(bp); + } +} + +/* + * this is called from uncommit in the forced-shutdown path. + * we need to check to see if the reference count on the log item + * is going to drop to zero. If so, unpin will free the log item + * so we need to free the item's descriptor (that points to the item) + * in the transaction. + */ +void +xfs_buf_item_unpin_remove( + xfs_buf_log_item_t *bip, + xfs_trans_t *tp) +{ + xfs_buf_t *bp; + xfs_log_item_desc_t *lidp; + int stale = 0; + + bp = bip->bli_buf; + /* + * will xfs_buf_item_unpin() call xfs_buf_item_relse()? + */ + if ((atomic_read(&bip->bli_refcount) == 1) && + (bip->bli_flags & XFS_BLI_STALE)) { + ASSERT(XFS_BUF_VALUSEMA(bip->bli_buf) <= 0); + xfs_buf_item_trace("UNPIN REMOVE", bip); + xfs_buftrace("XFS_UNPIN_REMOVE", bp); + /* + * yes -- clear the xaction descriptor in-use flag + * and free the chunk if required. We can safely + * do some work here and then call buf_item_unpin + * to do the rest because if the if is true, then + * we are holding the buffer locked so no one else + * will be able to bump up the refcount. + */ + lidp = xfs_trans_find_item(tp, (xfs_log_item_t *) bip); + stale = lidp->lid_flags & XFS_LID_BUF_STALE; + xfs_trans_free_item(tp, lidp); + /* + * Since the transaction no longer refers to the buffer, + * the buffer should no longer refer to the transaction. + */ + XFS_BUF_SET_FSPRIVATE2(bp, NULL); + } + + xfs_buf_item_unpin(bip, stale); + + return; +} + +/* + * This is called to attempt to lock the buffer associated with this + * buf log item. Don't sleep on the buffer lock. If we can't get + * the lock right away, return 0. If we can get the lock, pull the + * buffer from the free list, mark it busy, and return 1. + */ +uint +xfs_buf_item_trylock( + xfs_buf_log_item_t *bip) +{ + xfs_buf_t *bp; + + bp = bip->bli_buf; + + if (XFS_BUF_ISPINNED(bp)) { + return XFS_ITEM_PINNED; + } + + if (!XFS_BUF_CPSEMA(bp)) { + return XFS_ITEM_LOCKED; + } + + /* + * Remove the buffer from the free list. Only do this + * if it's on the free list. Private buffers like the + * superblock buffer are not. + */ + XFS_BUF_HOLD(bp); + + ASSERT(!(bip->bli_flags & XFS_BLI_STALE)); + xfs_buf_item_trace("TRYLOCK SUCCESS", bip); + return XFS_ITEM_SUCCESS; +} + +/* + * Release the buffer associated with the buf log item. + * If there is no dirty logged data associated with the + * buffer recorded in the buf log item, then free the + * buf log item and remove the reference to it in the + * buffer. + * + * This call ignores the recursion count. It is only called + * when the buffer should REALLY be unlocked, regardless + * of the recursion count. + * + * If the XFS_BLI_HOLD flag is set in the buf log item, then + * free the log item if necessary but do not unlock the buffer. + * This is for support of xfs_trans_bhold(). Make sure the + * XFS_BLI_HOLD field is cleared if we don't free the item. + */ +void +xfs_buf_item_unlock( + xfs_buf_log_item_t *bip) +{ + int aborted; + xfs_buf_t *bp; + uint hold; + + bp = bip->bli_buf; + xfs_buftrace("XFS_UNLOCK", bp); + + /* + * Clear the buffer's association with this transaction. + */ + XFS_BUF_SET_FSPRIVATE2(bp, NULL); + + /* + * If this is a transaction abort, don't return early. + * Instead, allow the brelse to happen. + * Normally it would be done for stale (cancelled) buffers + * at unpin time, but we'll never go through the pin/unpin + * cycle if we abort inside commit. + */ + aborted = (bip->bli_item.li_flags & XFS_LI_ABORTED) != 0; + + /* + * If the buf item is marked stale, then don't do anything. + * We'll unlock the buffer and free the buf item when the + * buffer is unpinned for the last time. + */ + if (bip->bli_flags & XFS_BLI_STALE) { + bip->bli_flags &= ~XFS_BLI_LOGGED; + xfs_buf_item_trace("UNLOCK STALE", bip); + ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL); + if (!aborted) + return; + } + + /* + * Drop the transaction's reference to the log item if + * it was not logged as part of the transaction. Otherwise + * we'll drop the reference in xfs_buf_item_unpin() when + * the transaction is really through with the buffer. + */ + if (!(bip->bli_flags & XFS_BLI_LOGGED)) { + atomic_dec(&bip->bli_refcount); + } else { + /* + * Clear the logged flag since this is per + * transaction state. + */ + bip->bli_flags &= ~XFS_BLI_LOGGED; + } + + /* + * Before possibly freeing the buf item, determine if we should + * release the buffer at the end of this routine. + */ + hold = bip->bli_flags & XFS_BLI_HOLD; + xfs_buf_item_trace("UNLOCK", bip); + + /* + * If the buf item isn't tracking any data, free it. + * Otherwise, if XFS_BLI_HOLD is set clear it. + */ + if (xfs_count_bits(bip->bli_format.blf_data_map, + bip->bli_format.blf_map_size, 0) == 0) { + xfs_buf_item_relse(bp); + } else if (hold) { + bip->bli_flags &= ~XFS_BLI_HOLD; + } + + /* + * Release the buffer if XFS_BLI_HOLD was not set. + */ + if (!hold) { + xfs_buf_relse(bp); + } +} + +/* + * This is called to find out where the oldest active copy of the + * buf log item in the on disk log resides now that the last log + * write of it completed at the given lsn. + * We always re-log all the dirty data in a buffer, so usually the + * latest copy in the on disk log is the only one that matters. For + * those cases we simply return the given lsn. + * + * The one exception to this is for buffers full of newly allocated + * inodes. These buffers are only relogged with the XFS_BLI_INODE_BUF + * flag set, indicating that only the di_next_unlinked fields from the + * inodes in the buffers will be replayed during recovery. If the + * original newly allocated inode images have not yet been flushed + * when the buffer is so relogged, then we need to make sure that we + * keep the old images in the 'active' portion of the log. We do this + * by returning the original lsn of that transaction here rather than + * the current one. + */ +xfs_lsn_t +xfs_buf_item_committed( + xfs_buf_log_item_t *bip, + xfs_lsn_t lsn) +{ + xfs_buf_item_trace("COMMITTED", bip); + if ((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) && + (bip->bli_item.li_lsn != 0)) { + return bip->bli_item.li_lsn; + } + return (lsn); +} + +/* + * This is called when the transaction holding the buffer is aborted. + * Just behave as if the transaction had been cancelled. If we're shutting down + * and have aborted this transaction, we'll trap this buffer when it tries to + * get written out. + */ +void +xfs_buf_item_abort( + xfs_buf_log_item_t *bip) +{ + xfs_buf_t *bp; + + bp = bip->bli_buf; + xfs_buftrace("XFS_ABORT", bp); + XFS_BUF_SUPER_STALE(bp); + xfs_buf_item_unlock(bip); + return; +} + +/* + * This is called to asynchronously write the buffer associated with this + * buf log item out to disk. The buffer will already have been locked by + * a successful call to xfs_buf_item_trylock(). If the buffer still has + * B_DELWRI set, then get it going out to disk with a call to bawrite(). + * If not, then just release the buffer. + */ +void +xfs_buf_item_push( + xfs_buf_log_item_t *bip) +{ + xfs_buf_t *bp; + + ASSERT(!(bip->bli_flags & XFS_BLI_STALE)); + xfs_buf_item_trace("PUSH", bip); + + bp = bip->bli_buf; + + if (XFS_BUF_ISDELAYWRITE(bp)) { + xfs_bawrite(bip->bli_item.li_mountp, bp); + } else { + xfs_buf_relse(bp); + } +} + +/* ARGSUSED */ +void +xfs_buf_item_committing(xfs_buf_log_item_t *bip, xfs_lsn_t commit_lsn) +{ +} + +/* + * This is the ops vector shared by all buf log items. + */ +struct xfs_item_ops xfs_buf_item_ops = { + .iop_size = (uint(*)(xfs_log_item_t*))xfs_buf_item_size, + .iop_format = (void(*)(xfs_log_item_t*, xfs_log_iovec_t*)) + xfs_buf_item_format, + .iop_pin = (void(*)(xfs_log_item_t*))xfs_buf_item_pin, + .iop_unpin = (void(*)(xfs_log_item_t*, int))xfs_buf_item_unpin, + .iop_unpin_remove = (void(*)(xfs_log_item_t*, xfs_trans_t *)) + xfs_buf_item_unpin_remove, + .iop_trylock = (uint(*)(xfs_log_item_t*))xfs_buf_item_trylock, + .iop_unlock = (void(*)(xfs_log_item_t*))xfs_buf_item_unlock, + .iop_committed = (xfs_lsn_t(*)(xfs_log_item_t*, xfs_lsn_t)) + xfs_buf_item_committed, + .iop_push = (void(*)(xfs_log_item_t*))xfs_buf_item_push, + .iop_abort = (void(*)(xfs_log_item_t*))xfs_buf_item_abort, + .iop_pushbuf = NULL, + .iop_committing = (void(*)(xfs_log_item_t*, xfs_lsn_t)) + xfs_buf_item_committing +}; + + +/* + * Allocate a new buf log item to go with the given buffer. + * Set the buffer's b_fsprivate field to point to the new + * buf log item. If there are other item's attached to the + * buffer (see xfs_buf_attach_iodone() below), then put the + * buf log item at the front. + */ +void +xfs_buf_item_init( + xfs_buf_t *bp, + xfs_mount_t *mp) +{ + xfs_log_item_t *lip; + xfs_buf_log_item_t *bip; + int chunks; + int map_size; + + /* + * Check to see if there is already a buf log item for + * this buffer. If there is, it is guaranteed to be + * the first. If we do already have one, there is + * nothing to do here so return. + */ + if (XFS_BUF_FSPRIVATE3(bp, xfs_mount_t *) != mp) + XFS_BUF_SET_FSPRIVATE3(bp, mp); + XFS_BUF_SET_BDSTRAT_FUNC(bp, xfs_bdstrat_cb); + if (XFS_BUF_FSPRIVATE(bp, void *) != NULL) { + lip = XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *); + if (lip->li_type == XFS_LI_BUF) { + return; + } + } + + /* + * chunks is the number of XFS_BLI_CHUNK size pieces + * the buffer can be divided into. Make sure not to + * truncate any pieces. map_size is the size of the + * bitmap needed to describe the chunks of the buffer. + */ + chunks = (int)((XFS_BUF_COUNT(bp) + (XFS_BLI_CHUNK - 1)) >> XFS_BLI_SHIFT); + map_size = (int)((chunks + NBWORD) >> BIT_TO_WORD_SHIFT); + + bip = (xfs_buf_log_item_t*)kmem_zone_zalloc(xfs_buf_item_zone, + KM_SLEEP); + bip->bli_item.li_type = XFS_LI_BUF; + bip->bli_item.li_ops = &xfs_buf_item_ops; + bip->bli_item.li_mountp = mp; + bip->bli_buf = bp; + bip->bli_format.blf_type = XFS_LI_BUF; + bip->bli_format.blf_blkno = (__int64_t)XFS_BUF_ADDR(bp); + bip->bli_format.blf_len = (ushort)BTOBB(XFS_BUF_COUNT(bp)); + bip->bli_format.blf_map_size = map_size; +#ifdef XFS_BLI_TRACE + bip->bli_trace = ktrace_alloc(XFS_BLI_TRACE_SIZE, KM_SLEEP); +#endif + +#ifdef XFS_TRANS_DEBUG + /* + * Allocate the arrays for tracking what needs to be logged + * and what our callers request to be logged. bli_orig + * holds a copy of the original, clean buffer for comparison + * against, and bli_logged keeps a 1 bit flag per byte in + * the buffer to indicate which bytes the callers have asked + * to have logged. + */ + bip->bli_orig = (char *)kmem_alloc(XFS_BUF_COUNT(bp), KM_SLEEP); + memcpy(bip->bli_orig, XFS_BUF_PTR(bp), XFS_BUF_COUNT(bp)); + bip->bli_logged = (char *)kmem_zalloc(XFS_BUF_COUNT(bp) / NBBY, KM_SLEEP); +#endif + + /* + * Put the buf item into the list of items attached to the + * buffer at the front. + */ + if (XFS_BUF_FSPRIVATE(bp, void *) != NULL) { + bip->bli_item.li_bio_list = + XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *); + } + XFS_BUF_SET_FSPRIVATE(bp, bip); +} + + +/* + * Mark bytes first through last inclusive as dirty in the buf + * item's bitmap. + */ +void +xfs_buf_item_log( + xfs_buf_log_item_t *bip, + uint first, + uint last) +{ + uint first_bit; + uint last_bit; + uint bits_to_set; + uint bits_set; + uint word_num; + uint *wordp; + uint bit; + uint end_bit; + uint mask; + + /* + * Mark the item as having some dirty data for + * quick reference in xfs_buf_item_dirty. + */ + bip->bli_flags |= XFS_BLI_DIRTY; + + /* + * Convert byte offsets to bit numbers. + */ + first_bit = first >> XFS_BLI_SHIFT; + last_bit = last >> XFS_BLI_SHIFT; + + /* + * Calculate the total number of bits to be set. + */ + bits_to_set = last_bit - first_bit + 1; + + /* + * Get a pointer to the first word in the bitmap + * to set a bit in. + */ + word_num = first_bit >> BIT_TO_WORD_SHIFT; + wordp = &(bip->bli_format.blf_data_map[word_num]); + + /* + * Calculate the starting bit in the first word. + */ + bit = first_bit & (uint)(NBWORD - 1); + + /* + * First set any bits in the first word of our range. + * If it starts at bit 0 of the word, it will be + * set below rather than here. That is what the variable + * bit tells us. The variable bits_set tracks the number + * of bits that have been set so far. End_bit is the number + * of the last bit to be set in this word plus one. + */ + if (bit) { + end_bit = MIN(bit + bits_to_set, (uint)NBWORD); + mask = ((1 << (end_bit - bit)) - 1) << bit; + *wordp |= mask; + wordp++; + bits_set = end_bit - bit; + } else { + bits_set = 0; + } + + /* + * Now set bits a whole word at a time that are between + * first_bit and last_bit. + */ + while ((bits_to_set - bits_set) >= NBWORD) { + *wordp |= 0xffffffff; + bits_set += NBWORD; + wordp++; + } + + /* + * Finally, set any bits left to be set in one last partial word. + */ + end_bit = bits_to_set - bits_set; + if (end_bit) { + mask = (1 << end_bit) - 1; + *wordp |= mask; + } + + xfs_buf_item_log_debug(bip, first, last); +} + + +/* + * Return 1 if the buffer has some data that has been logged (at any + * point, not just the current transaction) and 0 if not. + */ +uint +xfs_buf_item_dirty( + xfs_buf_log_item_t *bip) +{ + return (bip->bli_flags & XFS_BLI_DIRTY); +} + +/* + * This is called when the buf log item is no longer needed. It should + * free the buf log item associated with the given buffer and clear + * the buffer's pointer to the buf log item. If there are no more + * items in the list, clear the b_iodone field of the buffer (see + * xfs_buf_attach_iodone() below). + */ +void +xfs_buf_item_relse( + xfs_buf_t *bp) +{ + xfs_buf_log_item_t *bip; + + xfs_buftrace("XFS_RELSE", bp); + bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t*); + XFS_BUF_SET_FSPRIVATE(bp, bip->bli_item.li_bio_list); + if ((XFS_BUF_FSPRIVATE(bp, void *) == NULL) && + (XFS_BUF_IODONE_FUNC(bp) != NULL)) { + ASSERT((XFS_BUF_ISUNINITIAL(bp)) == 0); + XFS_BUF_CLR_IODONE_FUNC(bp); + } + +#ifdef XFS_TRANS_DEBUG + kmem_free(bip->bli_orig, XFS_BUF_COUNT(bp)); + bip->bli_orig = NULL; + kmem_free(bip->bli_logged, XFS_BUF_COUNT(bp) / NBBY); + bip->bli_logged = NULL; +#endif /* XFS_TRANS_DEBUG */ + +#ifdef XFS_BLI_TRACE + ktrace_free(bip->bli_trace); +#endif + kmem_zone_free(xfs_buf_item_zone, bip); +} + + +/* + * Add the given log item with its callback to the list of callbacks + * to be called when the buffer's I/O completes. If it is not set + * already, set the buffer's b_iodone() routine to be + * xfs_buf_iodone_callbacks() and link the log item into the list of + * items rooted at b_fsprivate. Items are always added as the second + * entry in the list if there is a first, because the buf item code + * assumes that the buf log item is first. + */ +void +xfs_buf_attach_iodone( + xfs_buf_t *bp, + void (*cb)(xfs_buf_t *, xfs_log_item_t *), + xfs_log_item_t *lip) +{ + xfs_log_item_t *head_lip; + + ASSERT(XFS_BUF_ISBUSY(bp)); + ASSERT(XFS_BUF_VALUSEMA(bp) <= 0); + + lip->li_cb = cb; + if (XFS_BUF_FSPRIVATE(bp, void *) != NULL) { + head_lip = XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *); + lip->li_bio_list = head_lip->li_bio_list; + head_lip->li_bio_list = lip; + } else { + XFS_BUF_SET_FSPRIVATE(bp, lip); + } + + ASSERT((XFS_BUF_IODONE_FUNC(bp) == xfs_buf_iodone_callbacks) || + (XFS_BUF_IODONE_FUNC(bp) == NULL)); + XFS_BUF_SET_IODONE_FUNC(bp, xfs_buf_iodone_callbacks); +} + +STATIC void +xfs_buf_do_callbacks( + xfs_buf_t *bp, + xfs_log_item_t *lip) +{ + xfs_log_item_t *nlip; + + while (lip != NULL) { + nlip = lip->li_bio_list; + ASSERT(lip->li_cb != NULL); + /* + * Clear the next pointer so we don't have any + * confusion if the item is added to another buf. + * Don't touch the log item after calling its + * callback, because it could have freed itself. + */ + lip->li_bio_list = NULL; + lip->li_cb(bp, lip); + lip = nlip; + } +} + +/* + * This is the iodone() function for buffers which have had callbacks + * attached to them by xfs_buf_attach_iodone(). It should remove each + * log item from the buffer's list and call the callback of each in turn. + * When done, the buffer's fsprivate field is set to NULL and the buffer + * is unlocked with a call to iodone(). + */ +void +xfs_buf_iodone_callbacks( + xfs_buf_t *bp) +{ + xfs_log_item_t *lip; + static ulong lasttime; + static xfs_buftarg_t *lasttarg; + xfs_mount_t *mp; + + ASSERT(XFS_BUF_FSPRIVATE(bp, void *) != NULL); + lip = XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *); + + if (XFS_BUF_GETERROR(bp) != 0) { + /* + * If we've already decided to shutdown the filesystem + * because of IO errors, there's no point in giving this + * a retry. + */ + mp = lip->li_mountp; + if (XFS_FORCED_SHUTDOWN(mp)) { + ASSERT(XFS_BUF_TARGET(bp) == mp->m_ddev_targp); + XFS_BUF_SUPER_STALE(bp); + xfs_buftrace("BUF_IODONE_CB", bp); + xfs_buf_do_callbacks(bp, lip); + XFS_BUF_SET_FSPRIVATE(bp, NULL); + XFS_BUF_CLR_IODONE_FUNC(bp); + + /* + * XFS_SHUT flag gets set when we go thru the + * entire buffer cache and deliberately start + * throwing away delayed write buffers. + * Since there's no biowait done on those, + * we should just brelse them. + */ + if (XFS_BUF_ISSHUT(bp)) { + XFS_BUF_UNSHUT(bp); + xfs_buf_relse(bp); + } else { + xfs_biodone(bp); + } + + return; + } + + if ((XFS_BUF_TARGET(bp) != lasttarg) || + (time_after(jiffies, (lasttime + 5*HZ)))) { + lasttime = jiffies; + prdev("XFS write error in file system meta-data " + "block 0x%llx in %s", + XFS_BUF_TARGET(bp), + (__uint64_t)XFS_BUF_ADDR(bp), mp->m_fsname); + } + lasttarg = XFS_BUF_TARGET(bp); + + if (XFS_BUF_ISASYNC(bp)) { + /* + * If the write was asynchronous then noone will be + * looking for the error. Clear the error state + * and write the buffer out again delayed write. + * + * XXXsup This is OK, so long as we catch these + * before we start the umount; we don't want these + * DELWRI metadata bufs to be hanging around. + */ + XFS_BUF_ERROR(bp,0); /* errno of 0 unsets the flag */ + + if (!(XFS_BUF_ISSTALE(bp))) { + XFS_BUF_DELAYWRITE(bp); + XFS_BUF_DONE(bp); + XFS_BUF_SET_START(bp); + } + ASSERT(XFS_BUF_IODONE_FUNC(bp)); + xfs_buftrace("BUF_IODONE ASYNC", bp); + xfs_buf_relse(bp); + } else { + /* + * If the write of the buffer was not asynchronous, + * then we want to make sure to return the error + * to the caller of bwrite(). Because of this we + * cannot clear the B_ERROR state at this point. + * Instead we install a callback function that + * will be called when the buffer is released, and + * that routine will clear the error state and + * set the buffer to be written out again after + * some delay. + */ + /* We actually overwrite the existing b-relse + function at times, but we're gonna be shutting down + anyway. */ + XFS_BUF_SET_BRELSE_FUNC(bp,xfs_buf_error_relse); + XFS_BUF_DONE(bp); + XFS_BUF_V_IODONESEMA(bp); + } + return; + } +#ifdef XFSERRORDEBUG + xfs_buftrace("XFS BUFCB NOERR", bp); +#endif + xfs_buf_do_callbacks(bp, lip); + XFS_BUF_SET_FSPRIVATE(bp, NULL); + XFS_BUF_CLR_IODONE_FUNC(bp); + xfs_biodone(bp); +} + +/* + * This is a callback routine attached to a buffer which gets an error + * when being written out synchronously. + */ +STATIC void +xfs_buf_error_relse( + xfs_buf_t *bp) +{ + xfs_log_item_t *lip; + xfs_mount_t *mp; + + lip = XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *); + mp = (xfs_mount_t *)lip->li_mountp; + ASSERT(XFS_BUF_TARGET(bp) == mp->m_ddev_targp); + + XFS_BUF_STALE(bp); + XFS_BUF_DONE(bp); + XFS_BUF_UNDELAYWRITE(bp); + XFS_BUF_ERROR(bp,0); + xfs_buftrace("BUF_ERROR_RELSE", bp); + if (! XFS_FORCED_SHUTDOWN(mp)) + xfs_force_shutdown(mp, XFS_METADATA_IO_ERROR); + /* + * We have to unpin the pinned buffers so do the + * callbacks. + */ + xfs_buf_do_callbacks(bp, lip); + XFS_BUF_SET_FSPRIVATE(bp, NULL); + XFS_BUF_CLR_IODONE_FUNC(bp); + XFS_BUF_SET_BRELSE_FUNC(bp,NULL); + xfs_buf_relse(bp); +} + + +/* + * This is the iodone() function for buffers which have been + * logged. It is called when they are eventually flushed out. + * It should remove the buf item from the AIL, and free the buf item. + * It is called by xfs_buf_iodone_callbacks() above which will take + * care of cleaning up the buffer itself. + */ +/* ARGSUSED */ +void +xfs_buf_iodone( + xfs_buf_t *bp, + xfs_buf_log_item_t *bip) +{ + struct xfs_mount *mp; + SPLDECL(s); + + ASSERT(bip->bli_buf == bp); + + mp = bip->bli_item.li_mountp; + + /* + * If we are forcibly shutting down, this may well be + * off the AIL already. That's because we simulate the + * log-committed callbacks to unpin these buffers. Or we may never + * have put this item on AIL because of the transaction was + * aborted forcibly. xfs_trans_delete_ail() takes care of these. + * + * Either way, AIL is useless if we're forcing a shutdown. + */ + AIL_LOCK(mp,s); + /* + * xfs_trans_delete_ail() drops the AIL lock. + */ + xfs_trans_delete_ail(mp, (xfs_log_item_t *)bip, s); + +#ifdef XFS_TRANS_DEBUG + kmem_free(bip->bli_orig, XFS_BUF_COUNT(bp)); + bip->bli_orig = NULL; + kmem_free(bip->bli_logged, XFS_BUF_COUNT(bp) / NBBY); + bip->bli_logged = NULL; +#endif /* XFS_TRANS_DEBUG */ + +#ifdef XFS_BLI_TRACE + ktrace_free(bip->bli_trace); +#endif + kmem_zone_free(xfs_buf_item_zone, bip); +} + +#if defined(XFS_BLI_TRACE) +void +xfs_buf_item_trace( + char *id, + xfs_buf_log_item_t *bip) +{ + xfs_buf_t *bp; + ASSERT(bip->bli_trace != NULL); + + bp = bip->bli_buf; + ktrace_enter(bip->bli_trace, + (void *)id, + (void *)bip->bli_buf, + (void *)((unsigned long)bip->bli_flags), + (void *)((unsigned long)bip->bli_recur), + (void *)((unsigned long)atomic_read(&bip->bli_refcount)), + (void *)((unsigned long) + (0xFFFFFFFF & XFS_BUF_ADDR(bp) >> 32)), + (void *)((unsigned long)(0xFFFFFFFF & XFS_BUF_ADDR(bp))), + (void *)((unsigned long)XFS_BUF_COUNT(bp)), + (void *)((unsigned long)XFS_BUF_BFLAGS(bp)), + XFS_BUF_FSPRIVATE(bp, void *), + XFS_BUF_FSPRIVATE2(bp, void *), + (void *)(unsigned long)XFS_BUF_ISPINNED(bp), + (void *)XFS_BUF_IODONE_FUNC(bp), + (void *)((unsigned long)(XFS_BUF_VALUSEMA(bp))), + (void *)bip->bli_item.li_desc, + (void *)((unsigned long)bip->bli_item.li_flags)); +} +#endif /* XFS_BLI_TRACE */ |
