/* * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc. * All Rights Reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation. * * This program is distributed in the hope that it would be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #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_bmap_btree.h" #include "xfs_alloc_btree.h" #include "xfs_ialloc_btree.h" #include "xfs_dinode.h" #include "xfs_inode.h" #include "xfs_buf_item.h" #include "xfs_trans_priv.h" #include "xfs_error.h" #include "xfs_rw.h" #include "xfs_trace.h" /* * Check to see if a buffer matching the given parameters is already * a part of the given transaction. */ STATIC struct xfs_buf * xfs_trans_buf_item_match( struct xfs_trans *tp, struct xfs_buftarg *target, xfs_daddr_t blkno, int len) { struct xfs_log_item_desc *lidp; struct xfs_buf_log_item *blip; len = BBTOB(len); list_for_each_entry(lidp, &tp->t_items, lid_trans) { blip = (struct xfs_buf_log_item *)lidp->lid_item; if (blip->bli_item.li_type == XFS_LI_BUF && blip->bli_buf->b_target == target && XFS_BUF_ADDR(blip->bli_buf) == blkno && BBTOB(blip->bli_buf->b_length) == len) return blip->bli_buf; } return NULL; } /* * Add the locked buffer to the transaction. * * The buffer must be locked, and it cannot be associated with any * transaction. * * If the buffer does not yet have a buf log item associated with it, * then allocate one for it. Then add the buf item to the transaction. */ STATIC void _xfs_trans_bjoin( struct xfs_trans *tp, struct xfs_buf *bp, int reset_recur) { struct xfs_buf_log_item *bip; ASSERT(bp->b_transp == NULL); /* * The xfs_buf_log_item pointer is stored in b_fsprivate. If * it doesn't have one yet, then allocate one and initialize it. * The checks to see if one is there are in xfs_buf_item_init(). */ xfs_buf_item_init(bp, tp->t_mountp); bip = bp->b_fspriv; ASSERT(!(bip->bli_flags & XFS_BLI_STALE)); ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_CANCEL)); ASSERT(!(bip->bli_flags & XFS_BLI_LOGGED)); if (reset_recur) bip->bli_recur = 0; /* * Take a reference for this transaction on the buf item. */ atomic_inc(&bip->bli_refcount); /* * Get a log_item_desc to point at the new item. */ xfs_trans_add_item(tp, &bip->bli_item); /* * Initialize b_fsprivate2 so we can find it with incore_match() * in xfs_trans_get_buf() and friends above. */ bp->b_transp = tp; } void xfs_trans_bjoin( struct xfs_trans *tp, struct xfs_buf *bp) { _xfs_trans_bjoin(tp, bp, 0); trace_xfs_trans_bjoin(bp->b_fspriv); } /* * Get and lock the buffer for the caller if it is not already * locked within the given transaction. If it is already locked * within the transaction, just increment its lock recursion count * and return a pointer to it. * * If the transaction pointer is NULL, make this just a normal * get_buf() call. */ xfs_buf_t * xfs_trans_get_buf(xfs_trans_t *tp, xfs_buftarg_t *target_dev, xfs_daddr_t blkno, int len, uint flags) { xfs_buf_t *bp; xfs_buf_log_item_t *bip; if (flags == 0) flags = XBF_LOCK | XBF_MAPPED; /* * Default to a normal get_buf() call if the tp is NULL. */ if (tp == NULL) return xfs_buf_get(target_dev, blkno, len, flags | XBF_DONT_BLOCK); /* * If we find the buffer in the cache with this transaction * pointer in its b_fsprivate2 field, then we know we already * have it locked. In this case we just increment the lock * recursion count and return the buffer to the caller. */ bp = xfs_trans_buf_item_match(tp, target_dev, blkno, len); if (bp != NULL) { ASSERT(xfs_buf_islocked(bp)); if (XFS_FORCED_SHUTDOWN(tp->t_mountp)) { xfs_buf_stale(bp); XFS_BUF_DONE(bp); } ASSERT(bp->b_transp == tp); bip = bp->b_fspriv; ASSERT(bip != NULL); ASSERT(atomic_read(&bip->bli_refcount) > 0); bip->bli_recur++; trace_xfs_trans_get_buf_recur(bip); return (bp); } /* * We always specify the XBF_DONT_BLOCK flag within a transaction * so that get_buf does not try to push out a delayed write buffer * which might cause another transaction to take place (if the * buffer was delayed alloc). Such recursive transactions can * easily deadlock with our current transaction as well as cause * us to run out of stack space. */ bp = xfs_buf_get(target_dev, blkno, len, flags | XBF_DONT_BLOCK); if (bp == NULL) { return NULL; } ASSERT(!bp->b_error); _xfs_trans_bjoin(tp, bp, 1); trace_xfs_trans_get_buf(bp->b_fspriv); return (bp); } /* * Get and lock the superblock buffer of this file system for the * given transaction. * * We don't need to use incore_match() here, because the superblock * buffer is a private buffer which we keep a pointer to in the * mount structure. */ xfs_buf_t * xfs_trans_getsb(xfs_trans_t *tp, struct xfs_mount *mp, int flags) { xfs_buf_t *bp; xfs_buf_log_item_t *bip; /* * Default to just trying to lock the superblock buffer * if tp is NULL. */ if (tp == NULL) { return (xfs_getsb(mp, flags)); } /* * If the superblock buffer already has this transaction * pointer in its b_fsprivate2 field, then we know we already * have it locked. In this case we just increment the lock * recursion count and return the buffer to the caller. */ bp = mp->m_sb_bp; if (bp->b_transp == tp) { bip = bp->b_fspriv; ASSERT(bip != NULL); ASSERT(atomic_read(&bip->bli_refcount) > 0); bip->bli_recur++; trace_xfs_trans_getsb_recur(bip); return (bp); } bp = xfs_getsb(mp, flags); if (bp == NULL) return NULL; _xfs_trans_bjoin(tp, bp, 1); trace_xfs_trans_getsb(bp->b_fspriv); return (bp); } #ifdef DEBUG xfs_buftarg_t *xfs_error_target; int xfs_do_error; int xfs_req_num; int xfs_error_mod = 33; #endif /* * Get and lock the buffer for the caller if it is not already * locked within the given transaction. If it has not yet been * read in, read it from disk. If it is already locked * within the transaction and already read in, just increment its * lock recursion count and return a pointer to it. * * If the transaction pointer is NULL, make this just a normal * read_buf() call. */ int xfs_trans_read_buf( xfs_mount_t *mp, xfs_trans_t *tp, xfs_buftarg_t *target, xfs_daddr_t blkno, int len, uint flags, xfs_buf_t **bpp) { xfs_buf_t *bp; xfs_buf_log_item_t *bip; int error; if (flags == 0) flags = XBF_LOCK | XBF_MAPPED; /* * Default to a normal get_buf() call if the tp is NULL. */ if (tp == NULL) { bp = xfs_buf_read(target, blkno, len, flags | XBF_DONT_BLOCK); if (!bp) return (flags & XBF_TRYLOCK) ? EAGAIN : XFS_ERROR(ENOMEM); if (bp->b_error) { error = bp->b_error; xfs_buf_ioerror_alert(bp, __func__); xfs_buf_relse(bp); return error; } #ifdef DEBUG if (xfs_do_error) { if (xfs_error_target == target) { if (((xfs_req_num++) % xfs_error_mod) == 0) { xfs_buf_relse(bp); xfs_debug(mp, "Returning error!"); return XFS_ERROR(EIO); } } } #endif if (XFS_FORCED_SHUTDOWN(mp)) goto shutdown_abort; *bpp = bp; return 0; } /* * If we find the buffer in the cache with this transaction * pointer in its b_fsprivate2 field, then we know we already * have it locked. If it is already read in we just increment * the lock recursion count and return the buffer to the caller. * If the buffer is not yet read in, then we read it in, increment * the lock recursion count, and return it to the caller. */ bp = xfs_trans_buf_item_match(tp, target, blkno, len); if (bp != NULL) { ASSERT(xfs_buf_islocked(bp)); ASSERT(bp->b_transp == tp); ASSERT(bp->b_fspriv != NULL); ASSERT(!bp->b_error); if (!(XFS_BUF_ISDONE(bp))) { trace_xfs_trans_read_buf_io(bp, _RET_IP_); ASSERT(!XFS_BUF_ISASYNC(bp)); XFS_BUF_READ(bp); xfsbdstrat(tp->t_mountp, bp); error = xfs_buf_iowait(bp); if (error) { xfs_buf_ioerror_alert(bp, __func__); xfs_buf_relse(bp); /* * We can gracefully recover from most read * errors. Ones we can't are those that happen * after the transaction's already dirty. */ if (tp->t_flags & XFS_TRANS_DIRTY) xfs_force_shutdown(tp->t_mountp, SHUTDOWN_META_IO_ERROR); return error; } } /* * We never locked this buf ourselves, so we shouldn't * brelse it either. Just get out. */ if (XFS_FORCED_SHUTDOWN(mp)) { trace_xfs_trans_read_buf_shut(bp, _RET_IP_); *bpp = NULL; return XFS_ERROR(EIO); } bip = bp->b_fspriv; bip->bli_recur++; ASSERT(atomic_read(&bip->bli_refcount) > 0); trace_xfs_trans_read_buf_recur(bip); *bpp = bp; return 0; } /* * We always specify the XBF_DONT_BLOCK flag within a transaction * so that get_buf does not try to push out a delayed write buffer * which might cause another transaction to take place (if the * buffer was delayed alloc). Such recursive transactions can * easily deadlock with our current transaction as well as cause * us to run out of stack space. */ bp = xfs_buf_read(target, blkno, len, flags | XBF_DONT_BLOCK); if (bp == NULL) { *bpp = NULL; return (flags & XBF_TRYLOCK) ? 0 : XFS_ERROR(ENOMEM); } if (bp->b_error) { error = bp->b_error; xfs_buf_stale(bp); XFS_BUF_DONE(bp); xfs_buf_ioerror_alert(bp, __func__); if (tp->t_flags & XFS_TRANS_DIRTY) xfs_force_shutdown(tp->t_mountp, SHUTDOWN_META_IO_ERROR); xfs_buf_relse(bp); return error; } #ifdef DEBUG if (xfs_do_error && !(tp->t_flags & XFS_TRANS_DIRTY)) { if (xfs_error_target == target) { if (((xfs_req_num++) % xfs_error_mod) == 0) { xfs_force_shutdown(tp->t_mountp, SHUTDOWN_META_IO_ERROR); xfs_buf_relse(bp); xfs_debug(mp, "Returning trans error!"); return XFS_ERROR(EIO); } } } #endif if (XFS_FORCED_SHUTDOWN(mp)) goto shutdown_abort; _xfs_trans_bjoin(tp, bp, 1); trace_xfs_trans_read_buf(bp->b_fspriv); *bpp = bp; return 0; shutdown_abort: trace_xfs_trans_read_buf_shut(bp, _RET_IP_); xfs_buf_relse(bp); *bpp = NULL; return XFS_ERROR(EIO); } /* * Release the buffer bp which was previously acquired with one of the * xfs_trans_... buffer allocation routines if the buffer has not * been modified within this transaction. If the buffer is modified * within this transaction, do decrement the recursion count but do * not release the buffer even if the count goes to 0. If the buffer is not * modified within the transaction, decrement the recursion count and * release the buffer if the recursion count goes to 0. * * If the buffer is to be released and it was not modified before * this transaction began, then free the buf_log_item associated with it. * * If the transaction pointer is NULL, make this just a normal * brelse() call. */ void xfs_trans_brelse(xfs_trans_t *tp, xfs_buf_t *bp) { xfs_buf_log_item_t *bip; /* * Default to a normal brelse() call if the tp is NULL. */ if (tp == NULL) { ASSERT(bp->b_transp == NULL); xfs_buf_relse(bp); return; } ASSERT(bp->b_transp == tp); bip = bp->b_fspriv; ASSERT(bip->bli_item.li_type == XFS_LI_BUF); ASSERT(!(bip->bli_flags & XFS_BLI_STALE)); ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_CANCEL)); ASSERT(atomic_read(&bip->bli_refcount) > 0); trace_xfs_trans_brelse(bip); /* * If the release is just for a recursive lock, * then decrement the count and return. */ if (bip->bli_recur > 0) { bip->bli_recur--; return; } /* * If the buffer is dirty within this transaction, we can't * release it until we commit. */ if (bip->bli_item.li_desc->lid_flags & XFS_LID_DIRTY) return; /* * If the buffer has been invalidated, then we can't release * it until the transaction commits to disk unless it is re-dirtied * as part of this transaction. This prevents us from pulling * the item from the AIL before we should. */ if (bip->bli_flags & XFS_BLI_STALE) return; ASSERT(!(bip->bli_flags & XFS_BLI_LOGGED)); /* * Free up the log item descriptor tracking the released item. */ xfs_trans_del_item(&bip->bli_item); /* * Clear the hold flag in the buf log item if it is set. * We wouldn't want the next user of the buffer to * get confused. */ if (bip->bli_flags & XFS_BLI_HOLD) { bip->bli_flags &= ~XFS_BLI_HOLD; } /* * Drop our reference to the buf log item. */ atomic_dec(&bip->bli_refcount); /* * If the buf item is not tracking data in the log, then * we must free it before releasing the buffer back to the * free pool. Before releasing the buffer to the free pool, * clear the transaction pointer in b_fsprivate2 to dissolve * its relation to this transaction. */ if (!xfs_buf_item_dirty(bip)) { /*** ASSERT(bp->b_pincount == 0); ***/ ASSERT(atomic_read(&bip->bli_refcount) == 0); ASSERT(!(bip->bli_item.li_flags & XFS_LI_IN_AIL)); ASSERT(!(bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF)); xfs_buf_item_relse(bp); } bp->b_transp = NULL; xfs_buf_relse(bp); } /* * Mark the buffer as not needing to be unlocked when the buf item's * IOP_UNLOCK() routine is called. The buffer must already be locked * and associated with the given transaction. */ /* ARGSUSED */ void xfs_trans_bhold(xfs_trans_t *tp, xfs_buf_t *bp) { xfs_buf_log_item_t *bip = bp->b_fspriv; ASSERT(bp->b_transp == tp); ASSERT(bip != NULL); ASSERT(!(bip->bli_flags & XFS_BLI_STALE)); ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_CANCEL)); ASSERT(atomic_read(&bip->bli_refcount) > 0); bip->bli_flags |= XFS_BLI_HOLD; trace_xfs_trans_bhold(bip); } /* * Cancel the previous buffer hold request made on this buffer * for this transaction. */ void xfs_trans_bhold_release(xfs_trans_t *tp, xfs_buf_t *bp) { xfs_buf_log_item_t *bip = bp->b_fspriv; ASSERT(bp->b_transp == tp); ASSERT(bip != NULL); ASSERT(!(bip->bli_flags & XFS_BLI_STALE)); ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_CANCEL)); ASSERT(atomic_read(&bip->bli_refcount) > 0); ASSERT(bip->bli_flags & XFS_BLI_HOLD); bip->bli_flags &= ~XFS_BLI_HOLD; trace_xfs_trans_bhold_release(bip); } /* * This is called to mark bytes first through last inclusive of the given * buffer as needing to be logged when the transaction is committed. * The buffer must already be associated with the given transaction. * * First and last are numbers relative to the beginning of this buffer, * so the first byte in the buffer is numbered 0 regardless of the * value of b_blkno. */ void xfs_trans_log_buf(xfs_trans_t *tp, xfs_buf_t *bp, uint first, uint last) { xfs_buf_log_item_t *bip = bp->b_fspriv; ASSERT(bp->b_transp == tp); ASSERT(bip != NULL); ASSERT(first <= last && last < BBTOB(bp->b_length)); ASSERT(bp->b_iodone == NULL || bp->b_iodone == xfs_buf_iodone_callbacks); /* * Mark the buffer as needing to be written out eventually, * and set its iodone function to remove the buffer's buf log * item from the AIL and free it when the buffer is flushed * to disk. See xfs_buf_attach_iodone() for more details * on li_cb and xfs_buf_iodone_callbacks(). * If we end up aborting this transaction, we trap this buffer * inside the b_bdstrat callback so that this won't get written to * disk. */ XFS_BUF_DONE(bp); ASSERT(atomic_read(&bip->bli_refcount) > 0); bp->b_iodone = xfs_buf_iodone_callbacks; bip->bli_item.li_cb = xfs_buf_iodone; trace_xfs_trans_log_buf(bip); /* * If we invalidated the buffer within this transaction, then * cancel the invalidation now that we're dirtying the buffer * again. There are no races with the code in xfs_buf_item_unpin(), * because we have a reference to the buffer this entire time. */ if (bip->bli_flags & XFS_BLI_STALE) { bip->bli_flags &= ~XFS_BLI_STALE; ASSERT(XFS_BUF_ISSTALE(bp)); XFS_BUF_UNSTALE(bp); bip->bli_format.blf_flags &= ~XFS_BLF_CANCEL; } tp->t_flags |= XFS_TRANS_DIRTY; bip->bli_item.li_desc->lid_flags |= XFS_LID_DIRTY; bip->bli_flags |= XFS_BLI_LOGGED; xfs_buf_item_log(bip, first, last); } /* * Invalidate a buffer that is being used within a transaction. * * Typically this is because the blocks in the buffer are being freed, so we * need to prevent it from being written out when we're done. Allowing it * to be written again might overwrite data in the free blocks if they are * reallocated to a file. * * We prevent the buffer from being written out by marking it stale. We can't * get rid of the buf log item at this point because the buffer may still be * pinned by another transaction. If that is the case, then we'll wait until * the buffer is committed to disk for the last time (we can tell by the ref * count) and free it in xfs_buf_item_unpin(). Until that happens we will * keep the buffer locked so that the buffer and buf log item are not reused. * * We also set the XFS_BLF_CANCEL flag in the buf log format structure and log * the buf item. This will be used at recovery time to determine that copies * of the buffer in the log before this should not be replayed. * * We mark the item descriptor and the transaction dirty so that we'll hold * the buffer until after the commit. * * Since we're invalidating the buffer, we also clear the state about which * parts of the buffer have been logged. We also clear the flag indicating * that this is an inode buffer since the data in the buffer will no longer * be valid. * * We set the stale bit in the buffer as well since we're getting rid of it. */ void xfs_trans_binval( xfs_trans_t *tp, xfs_buf_t *bp) { xfs_buf_log_item_t *bip = bp->b_fspriv; ASSERT(bp->b_transp == tp); ASSERT(bip != NULL); ASSERT(atomic_read(&bip->bli_refcount) > 0); trace_xfs_trans_binval(bip); if (bip->bli_flags & XFS_BLI_STALE) { /* * If the buffer is already invalidated, then * just return. */ ASSERT(XFS_BUF_ISSTALE(bp)); ASSERT(!(bip->bli_flags & (XFS_BLI_LOGGED | XFS_BLI_DIRTY))); ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_INODE_BUF)); ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL); ASSERT(bip->bli_item.li_desc->lid_flags & XFS_LID_DIRTY); ASSERT(tp->t_flags & XFS_TRANS_DIRTY); return; } xfs_buf_stale(bp); bip->bli_flags |= XFS_BLI_STALE; bip->bli_flags &= ~(XFS_BLI_INODE_BUF | XFS_BLI_LOGGED | XFS_BLI_DIRTY); bip->bli_format.blf_flags &= ~XFS_BLF_INODE_BUF; bip->bli_format.blf_flags |= XFS_BLF_CANCEL; memset((char *)(bip->bli_format.blf_data_map), 0, (bip->bli_format.blf_map_size * sizeof(uint))); bip->bli_item.li_desc->lid_flags |= XFS_LID_DIRTY; tp->t_flags |= XFS_TRANS_DIRTY; } /* * This call is used to indicate that the buffer contains on-disk inodes which * must be handled specially during recovery. They require special handling * because only the di_next_unlinked from the inodes in the buffer should be * recovered. The rest of the data in the buffer is logged via the inodes * themselves. * * All we do is set the XFS_BLI_INODE_BUF flag in the items flags so it can be * transferred to the buffer's log format structure so that we'll know what to * do at recovery time. */ void xfs_trans_inode_buf( xfs_trans_t *tp, xfs_buf_t *bp) { xfs_buf_log_item_t *bip = bp->b_fspriv; ASSERT(bp->b_transp == tp); ASSERT(bip != NULL); ASSERT(atomic_read(&bip->bli_refcount) > 0); bip->bli_flags |= XFS_BLI_INODE_BUF; } /* * This call is used to indicate that the buffer is going to * be staled and was an inode buffer. This means it gets * special processing during unpin - where any inodes * associated with the buffer should be removed from ail. * There is also special processing during recovery, * any replay of the inodes in the buffer needs to be * prevented as the buffer may have been reused. */ void xfs_trans_stale_inode_buf( xfs_trans_t *tp, xfs_buf_t *bp) { xfs_buf_log_item_t *bip = bp->b_fspriv; ASSERT(bp->b_transp == tp); ASSERT(bip != NULL); ASSERT(atomic_read(&bip->bli_refcount) > 0); bip->bli_flags |= XFS_BLI_STALE_INODE; bip->bli_item.li_cb = xfs_buf_iodone; } /* * Mark the buffer as being one which contains newly allocated * inodes. We need to make sure that even if this buffer is * relogged as an 'inode buf' we still recover all of the inode * images in the face of a crash. This works in coordination with * xfs_buf_item_committed() to ensure that the buffer remains in the * AIL at its original location even after it has been relogged. */ /* ARGSUSED */ void xfs_trans_inode_alloc_buf( xfs_trans_t *tp, xfs_buf_t *bp) { xfs_buf_log_item_t *bip = bp->b_fspriv; ASSERT(bp->b_transp == tp); ASSERT(bip != NULL); ASSERT(atomic_read(&bip->bli_refcount) > 0); bip->bli_flags |= XFS_BLI_INODE_ALLOC_BUF; } /* * Similar to xfs_trans_inode_buf(), this marks the buffer as a cluster of * dquots. However, unlike in inode buffer recovery, dquot buffers get * recovered in their entirety. (Hence, no XFS_BLI_DQUOT_ALLOC_BUF flag). * The only thing that makes dquot buffers different from regular * buffers is that we must not replay dquot bufs when recovering * if a _corresponding_ quotaoff has happened. We also have to distinguish * between usr dquot bufs and grp dquot bufs, because usr and grp quotas * can be turned off independently. */ /* ARGSUSED */ void xfs_trans_dquot_buf( xfs_trans_t *tp, xfs_buf_t *bp, uint type) { xfs_buf_log_item_t *bip = bp->b_fspriv; ASSERT(bp->b_transp == tp); ASSERT(bip != NULL); ASSERT(type == XFS_BLF_UDQUOT_BUF || type == XFS_BLF_PDQUOT_BUF || type == XFS_BLF_GDQUOT_BUF); ASSERT(atomic_read(&bip->bli_refcount) > 0); bip->bli_format.blf_flags |= type; }