diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/xfs/xfs_buf_item.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/xfs/xfs_buf_item.c | 1050 |
1 files changed, 0 insertions, 1050 deletions
diff --git a/ANDROID_3.4.5/fs/xfs/xfs_buf_item.c b/ANDROID_3.4.5/fs/xfs/xfs_buf_item.c deleted file mode 100644 index eac97ef8..00000000 --- a/ANDROID_3.4.5/fs/xfs/xfs_buf_item.c +++ /dev/null @@ -1,1050 +0,0 @@ -/* - * Copyright (c) 2000-2005 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 - */ -#include "xfs.h" -#include "xfs_fs.h" -#include "xfs_types.h" -#include "xfs_bit.h" -#include "xfs_log.h" -#include "xfs_inum.h" -#include "xfs_trans.h" -#include "xfs_sb.h" -#include "xfs_ag.h" -#include "xfs_mount.h" -#include "xfs_buf_item.h" -#include "xfs_trans_priv.h" -#include "xfs_error.h" -#include "xfs_trace.h" - - -kmem_zone_t *xfs_buf_item_zone; - -static inline struct xfs_buf_log_item *BUF_ITEM(struct xfs_log_item *lip) -{ - return container_of(lip, struct xfs_buf_log_item, bli_item); -} - - -#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_BLF_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 = bp->b_fspriv; - uint nbytes; - - 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 callers 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 mismatch 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(bp->b_addr != NULL); - orig = bip->bli_orig; - buffer = bp->b_addr; - for (x = 0; x < XFS_BUF_COUNT(bp); x++) { - if (orig[x] != buffer[x] && !btst(bip->bli_logged, x)) { - xfs_emerg(bp->b_mount, - "%s: bip %x buffer %x orig %x index %d", - __func__, bip, bp, orig, x); - ASSERT(0); - } - } -} -#else -#define xfs_buf_item_log_debug(x,y,z) -#define xfs_buf_item_log_check(x) -#endif - -STATIC void xfs_buf_do_callbacks(struct xfs_buf *bp); - -/* - * 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. - */ -STATIC uint -xfs_buf_item_size( - struct xfs_log_item *lip) -{ - struct xfs_buf_log_item *bip = BUF_ITEM(lip); - struct xfs_buf *bp = bip->bli_buf; - uint nvecs; - int next_bit; - int last_bit; - - 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. - */ - trace_xfs_buf_item_size_stale(bip); - ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL); - return 1; - } - - 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_BLF_CHUNK) != - (xfs_buf_offset(bp, last_bit * XFS_BLF_CHUNK) + - XFS_BLF_CHUNK)) { - last_bit = next_bit; - nvecs++; - } else { - last_bit++; - } - } - - trace_xfs_buf_item_size(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. - */ -STATIC void -xfs_buf_item_format( - struct xfs_log_item *lip, - struct xfs_log_iovec *vecp) -{ - struct xfs_buf_log_item *bip = BUF_ITEM(lip); - struct xfs_buf *bp = bip->bli_buf; - uint base_size; - uint nvecs; - 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)); - - /* - * 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 = &bip->bli_format; - vecp->i_len = base_size; - vecp->i_type = XLOG_REG_TYPE_BFORMAT; - vecp++; - nvecs = 1; - - /* - * If it is an inode buffer, transfer the in-memory state to the - * format flags and clear the in-memory state. We do not transfer - * this state if the inode buffer allocation has not yet been committed - * to the log as setting the XFS_BLI_INODE_BUF flag will prevent - * correct replay of the inode allocation. - */ - if (bip->bli_flags & XFS_BLI_INODE_BUF) { - if (!((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) && - xfs_log_item_in_current_chkpt(lip))) - bip->bli_format.blf_flags |= XFS_BLF_INODE_BUF; - bip->bli_flags &= ~XFS_BLI_INODE_BUF; - } - - 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. - */ - trace_xfs_buf_item_format_stale(bip); - ASSERT(bip->bli_format.blf_flags & XFS_BLF_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_BLF_CHUNK; - vecp->i_addr = xfs_buf_offset(bp, buffer_offset); - vecp->i_len = nbits * XFS_BLF_CHUNK; - vecp->i_type = XLOG_REG_TYPE_BCHUNK; - nvecs++; - break; - } else if (next_bit != last_bit + 1) { - buffer_offset = first_bit * XFS_BLF_CHUNK; - vecp->i_addr = xfs_buf_offset(bp, buffer_offset); - vecp->i_len = nbits * XFS_BLF_CHUNK; - vecp->i_type = XLOG_REG_TYPE_BCHUNK; - nvecs++; - vecp++; - first_bit = next_bit; - last_bit = next_bit; - nbits = 1; - } else if (xfs_buf_offset(bp, next_bit << XFS_BLF_SHIFT) != - (xfs_buf_offset(bp, last_bit << XFS_BLF_SHIFT) + - XFS_BLF_CHUNK)) { - buffer_offset = first_bit * XFS_BLF_CHUNK; - vecp->i_addr = xfs_buf_offset(bp, buffer_offset); - vecp->i_len = nbits * XFS_BLF_CHUNK; - vecp->i_type = XLOG_REG_TYPE_BCHUNK; -/* 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. - */ - trace_xfs_buf_item_format(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. - * - * We also always take a reference to the buffer log item here so that the bli - * is held while the item is pinned in memory. This means that we can - * unconditionally drop the reference count a transaction holds when the - * transaction is completed. - */ -STATIC void -xfs_buf_item_pin( - struct xfs_log_item *lip) -{ - struct xfs_buf_log_item *bip = BUF_ITEM(lip); - - ASSERT(atomic_read(&bip->bli_refcount) > 0); - ASSERT((bip->bli_flags & XFS_BLI_LOGGED) || - (bip->bli_flags & XFS_BLI_STALE)); - - trace_xfs_buf_item_pin(bip); - - atomic_inc(&bip->bli_refcount); - atomic_inc(&bip->bli_buf->b_pin_count); -} - -/* - * 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(). - * - * 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. - * - * If the remove flag is set we are called from uncommit in the - * forced-shutdown path. If that is true and the reference count on - * the log item is going to drop to zero we need to free the item's - * descriptor in the transaction. - */ -STATIC void -xfs_buf_item_unpin( - struct xfs_log_item *lip, - int remove) -{ - struct xfs_buf_log_item *bip = BUF_ITEM(lip); - xfs_buf_t *bp = bip->bli_buf; - struct xfs_ail *ailp = lip->li_ailp; - int stale = bip->bli_flags & XFS_BLI_STALE; - int freed; - - ASSERT(bp->b_fspriv == bip); - ASSERT(atomic_read(&bip->bli_refcount) > 0); - - trace_xfs_buf_item_unpin(bip); - - freed = atomic_dec_and_test(&bip->bli_refcount); - - if (atomic_dec_and_test(&bp->b_pin_count)) - wake_up_all(&bp->b_waiters); - - if (freed && stale) { - ASSERT(bip->bli_flags & XFS_BLI_STALE); - ASSERT(xfs_buf_islocked(bp)); - ASSERT(!(XFS_BUF_ISDELAYWRITE(bp))); - ASSERT(XFS_BUF_ISSTALE(bp)); - ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL); - - trace_xfs_buf_item_unpin_stale(bip); - - if (remove) { - /* - * If we are in a transaction context, we have to - * remove the log item from the transaction as we are - * about to release our reference to the buffer. If we - * don't, the unlock that occurs later in - * xfs_trans_uncommit() will try to reference the - * buffer which we no longer have a hold on. - */ - if (lip->li_desc) - xfs_trans_del_item(lip); - - /* - * Since the transaction no longer refers to the buffer, - * the buffer should no longer refer to the transaction. - */ - bp->b_transp = NULL; - } - - /* - * If we get called here because of an IO error, we may - * or may not have the item on the AIL. xfs_trans_ail_delete() - * will take care of that situation. - * xfs_trans_ail_delete() drops the AIL lock. - */ - if (bip->bli_flags & XFS_BLI_STALE_INODE) { - xfs_buf_do_callbacks(bp); - bp->b_fspriv = NULL; - bp->b_iodone = NULL; - } else { - spin_lock(&ailp->xa_lock); - xfs_trans_ail_delete(ailp, (xfs_log_item_t *)bip); - xfs_buf_item_relse(bp); - ASSERT(bp->b_fspriv == NULL); - } - xfs_buf_relse(bp); - } -} - -/* - * 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, take a - * reference to the buffer. If this is a delayed write buffer that - * needs AIL help to be written back, invoke the pushbuf routine - * rather than the normal success path. - */ -STATIC uint -xfs_buf_item_trylock( - struct xfs_log_item *lip) -{ - struct xfs_buf_log_item *bip = BUF_ITEM(lip); - struct xfs_buf *bp = bip->bli_buf; - - if (xfs_buf_ispinned(bp)) - return XFS_ITEM_PINNED; - if (!xfs_buf_trylock(bp)) - return XFS_ITEM_LOCKED; - - /* take a reference to the buffer. */ - xfs_buf_hold(bp); - - ASSERT(!(bip->bli_flags & XFS_BLI_STALE)); - trace_xfs_buf_item_trylock(bip); - if (XFS_BUF_ISDELAYWRITE(bp)) - return XFS_ITEM_PUSHBUF; - 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. - * - * We unconditionally drop the transaction's reference to the log item. If the - * item was logged, then another reference was taken when it was pinned, so we - * can safely drop the transaction reference now. This also allows us to avoid - * potential races with the unpin code freeing the bli by not referencing the - * bli after we've dropped the reference 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. - */ -STATIC void -xfs_buf_item_unlock( - struct xfs_log_item *lip) -{ - struct xfs_buf_log_item *bip = BUF_ITEM(lip); - struct xfs_buf *bp = bip->bli_buf; - int aborted; - uint hold; - - /* Clear the buffer's association with this transaction. */ - bp->b_transp = 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 = (lip->li_flags & XFS_LI_ABORTED) != 0; - - /* - * 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; - - /* Clear the per transaction state. */ - bip->bli_flags &= ~(XFS_BLI_LOGGED | XFS_BLI_HOLD); - - /* - * 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) { - trace_xfs_buf_item_unlock_stale(bip); - ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL); - if (!aborted) { - atomic_dec(&bip->bli_refcount); - return; - } - } - - trace_xfs_buf_item_unlock(bip); - - /* - * If the buf item isn't tracking any data, free it, otherwise drop the - * reference we hold to it. - */ - if (xfs_bitmap_empty(bip->bli_format.blf_data_map, - bip->bli_format.blf_map_size)) - xfs_buf_item_relse(bp); - else - atomic_dec(&bip->bli_refcount); - - 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. - */ -STATIC xfs_lsn_t -xfs_buf_item_committed( - struct xfs_log_item *lip, - xfs_lsn_t lsn) -{ - struct xfs_buf_log_item *bip = BUF_ITEM(lip); - - trace_xfs_buf_item_committed(bip); - - if ((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) && lip->li_lsn != 0) - return lip->li_lsn; - return lsn; -} - -/* - * The buffer is locked, but is not a delayed write buffer. This happens - * if we race with IO completion and hence we don't want to try to write it - * again. Just release the buffer. - */ -STATIC void -xfs_buf_item_push( - struct xfs_log_item *lip) -{ - struct xfs_buf_log_item *bip = BUF_ITEM(lip); - struct xfs_buf *bp = bip->bli_buf; - - ASSERT(!(bip->bli_flags & XFS_BLI_STALE)); - ASSERT(!XFS_BUF_ISDELAYWRITE(bp)); - - trace_xfs_buf_item_push(bip); - - xfs_buf_relse(bp); -} - -/* - * The buffer is locked and is a delayed write buffer. Promote the buffer - * in the delayed write queue as the caller knows that they must invoke - * the xfsbufd to get this buffer written. We have to unlock the buffer - * to allow the xfsbufd to write it, too. - */ -STATIC bool -xfs_buf_item_pushbuf( - struct xfs_log_item *lip) -{ - struct xfs_buf_log_item *bip = BUF_ITEM(lip); - struct xfs_buf *bp = bip->bli_buf; - - ASSERT(!(bip->bli_flags & XFS_BLI_STALE)); - ASSERT(XFS_BUF_ISDELAYWRITE(bp)); - - trace_xfs_buf_item_pushbuf(bip); - - xfs_buf_delwri_promote(bp); - xfs_buf_relse(bp); - return true; -} - -STATIC void -xfs_buf_item_committing( - struct xfs_log_item *lip, - xfs_lsn_t commit_lsn) -{ -} - -/* - * This is the ops vector shared by all buf log items. - */ -static const struct xfs_item_ops xfs_buf_item_ops = { - .iop_size = xfs_buf_item_size, - .iop_format = xfs_buf_item_format, - .iop_pin = xfs_buf_item_pin, - .iop_unpin = xfs_buf_item_unpin, - .iop_trylock = xfs_buf_item_trylock, - .iop_unlock = xfs_buf_item_unlock, - .iop_committed = xfs_buf_item_committed, - .iop_push = xfs_buf_item_push, - .iop_pushbuf = xfs_buf_item_pushbuf, - .iop_committing = 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 = bp->b_fspriv; - 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. - */ - ASSERT(bp->b_target->bt_mount == mp); - if (lip != NULL && lip->li_type == XFS_LI_BUF) - return; - - /* - * chunks is the number of XFS_BLF_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_BLF_CHUNK - 1)) >> XFS_BLF_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); - xfs_log_item_init(mp, &bip->bli_item, XFS_LI_BUF, &xfs_buf_item_ops); - bip->bli_buf = bp; - xfs_buf_hold(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_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, bp->b_addr, 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 (bp->b_fspriv) - bip->bli_item.li_bio_list = bp->b_fspriv; - bp->b_fspriv = 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_BLF_SHIFT; - last_bit = last >> XFS_BLF_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); -} - -STATIC void -xfs_buf_item_free( - xfs_buf_log_item_t *bip) -{ -#ifdef XFS_TRANS_DEBUG - kmem_free(bip->bli_orig); - kmem_free(bip->bli_logged); -#endif /* XFS_TRANS_DEBUG */ - - kmem_zone_free(xfs_buf_item_zone, bip); -} - -/* - * 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; - - trace_xfs_buf_item_relse(bp, _RET_IP_); - - bip = bp->b_fspriv; - bp->b_fspriv = bip->bli_item.li_bio_list; - if (bp->b_fspriv == NULL) - bp->b_iodone = NULL; - - xfs_buf_rele(bp); - xfs_buf_item_free(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_islocked(bp)); - - lip->li_cb = cb; - head_lip = bp->b_fspriv; - if (head_lip) { - lip->li_bio_list = head_lip->li_bio_list; - head_lip->li_bio_list = lip; - } else { - bp->b_fspriv = lip; - } - - ASSERT(bp->b_iodone == NULL || - bp->b_iodone == xfs_buf_iodone_callbacks); - bp->b_iodone = xfs_buf_iodone_callbacks; -} - -/* - * We can have many callbacks on a buffer. Running the callbacks individually - * can cause a lot of contention on the AIL lock, so we allow for a single - * callback to be able to scan the remaining lip->li_bio_list for other items - * of the same type and callback to be processed in the first call. - * - * As a result, the loop walking the callback list below will also modify the - * list. it removes the first item from the list and then runs the callback. - * The loop then restarts from the new head of the list. This allows the - * callback to scan and modify the list attached to the buffer and we don't - * have to care about maintaining a next item pointer. - */ -STATIC void -xfs_buf_do_callbacks( - struct xfs_buf *bp) -{ - struct xfs_log_item *lip; - - while ((lip = bp->b_fspriv) != NULL) { - bp->b_fspriv = 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); - } -} - -/* - * 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( - struct xfs_buf *bp) -{ - struct xfs_log_item *lip = bp->b_fspriv; - struct xfs_mount *mp = lip->li_mountp; - static ulong lasttime; - static xfs_buftarg_t *lasttarg; - - if (likely(!xfs_buf_geterror(bp))) - goto do_callbacks; - - /* - * If we've already decided to shutdown the filesystem because of - * I/O errors, there's no point in giving this a retry. - */ - if (XFS_FORCED_SHUTDOWN(mp)) { - xfs_buf_stale(bp); - XFS_BUF_DONE(bp); - trace_xfs_buf_item_iodone(bp, _RET_IP_); - goto do_callbacks; - } - - if (bp->b_target != lasttarg || - time_after(jiffies, (lasttime + 5*HZ))) { - lasttime = jiffies; - xfs_buf_ioerror_alert(bp, __func__); - } - lasttarg = bp->b_target; - - /* - * If the write was asynchronous then no one will be looking for the - * error. Clear the error state and write the buffer out again. - * - * During sync or umount we'll write all pending buffers again - * synchronous, which will catch these errors if they keep hanging - * around. - */ - if (XFS_BUF_ISASYNC(bp)) { - xfs_buf_ioerror(bp, 0); /* errno of 0 unsets the flag */ - - if (!XFS_BUF_ISSTALE(bp)) { - xfs_buf_delwri_queue(bp); - XFS_BUF_DONE(bp); - } - ASSERT(bp->b_iodone != NULL); - trace_xfs_buf_item_iodone_async(bp, _RET_IP_); - xfs_buf_relse(bp); - return; - } - - /* - * If the write of the buffer was synchronous, we want to make - * sure to return the error to the caller of xfs_bwrite(). - */ - xfs_buf_stale(bp); - XFS_BUF_DONE(bp); - - trace_xfs_buf_error_relse(bp, _RET_IP_); - -do_callbacks: - xfs_buf_do_callbacks(bp); - bp->b_fspriv = NULL; - bp->b_iodone = NULL; - xfs_buf_ioend(bp, 0); -} - -/* - * 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. - */ -void -xfs_buf_iodone( - struct xfs_buf *bp, - struct xfs_log_item *lip) -{ - struct xfs_ail *ailp = lip->li_ailp; - - ASSERT(BUF_ITEM(lip)->bli_buf == bp); - - xfs_buf_rele(bp); - - /* - * 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_ail_delete() takes care of these. - * - * Either way, AIL is useless if we're forcing a shutdown. - */ - spin_lock(&ailp->xa_lock); - xfs_trans_ail_delete(ailp, lip); - xfs_buf_item_free(BUF_ITEM(lip)); -} |