diff options
Diffstat (limited to 'fs/xfs/linux-2.6/xfs_sync.c')
| -rw-r--r-- | fs/xfs/linux-2.6/xfs_sync.c | 762 |
1 files changed, 762 insertions, 0 deletions
diff --git a/fs/xfs/linux-2.6/xfs_sync.c b/fs/xfs/linux-2.6/xfs_sync.c new file mode 100644 index 000000000000..2ed035354c26 --- /dev/null +++ b/fs/xfs/linux-2.6/xfs_sync.c @@ -0,0 +1,762 @@ +/* + * 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_dir2.h" +#include "xfs_dmapi.h" +#include "xfs_mount.h" +#include "xfs_bmap_btree.h" +#include "xfs_alloc_btree.h" +#include "xfs_ialloc_btree.h" +#include "xfs_btree.h" +#include "xfs_dir2_sf.h" +#include "xfs_attr_sf.h" +#include "xfs_inode.h" +#include "xfs_dinode.h" +#include "xfs_error.h" +#include "xfs_mru_cache.h" +#include "xfs_filestream.h" +#include "xfs_vnodeops.h" +#include "xfs_utils.h" +#include "xfs_buf_item.h" +#include "xfs_inode_item.h" +#include "xfs_rw.h" + +#include <linux/kthread.h> +#include <linux/freezer.h> + +/* + * Sync all the inodes in the given AG according to the + * direction given by the flags. + */ +STATIC int +xfs_sync_inodes_ag( + xfs_mount_t *mp, + int ag, + int flags) +{ + xfs_perag_t *pag = &mp->m_perag[ag]; + int nr_found; + uint32_t first_index = 0; + int error = 0; + int last_error = 0; + int fflag = XFS_B_ASYNC; + + if (flags & SYNC_DELWRI) + fflag = XFS_B_DELWRI; + if (flags & SYNC_WAIT) + fflag = 0; /* synchronous overrides all */ + + do { + struct inode *inode; + xfs_inode_t *ip = NULL; + int lock_flags = XFS_ILOCK_SHARED; + + /* + * use a gang lookup to find the next inode in the tree + * as the tree is sparse and a gang lookup walks to find + * the number of objects requested. + */ + read_lock(&pag->pag_ici_lock); + nr_found = radix_tree_gang_lookup(&pag->pag_ici_root, + (void**)&ip, first_index, 1); + + if (!nr_found) { + read_unlock(&pag->pag_ici_lock); + break; + } + + /* + * Update the index for the next lookup. Catch overflows + * into the next AG range which can occur if we have inodes + * in the last block of the AG and we are currently + * pointing to the last inode. + */ + first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1); + if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino)) { + read_unlock(&pag->pag_ici_lock); + break; + } + + /* nothing to sync during shutdown */ + if (XFS_FORCED_SHUTDOWN(mp)) { + read_unlock(&pag->pag_ici_lock); + return 0; + } + + /* + * If we can't get a reference on the inode, it must be + * in reclaim. Leave it for the reclaim code to flush. + */ + inode = VFS_I(ip); + if (!igrab(inode)) { + read_unlock(&pag->pag_ici_lock); + continue; + } + read_unlock(&pag->pag_ici_lock); + + /* avoid new or bad inodes */ + if (is_bad_inode(inode) || + xfs_iflags_test(ip, XFS_INEW)) { + IRELE(ip); + continue; + } + + /* + * If we have to flush data or wait for I/O completion + * we need to hold the iolock. + */ + if ((flags & SYNC_DELWRI) && VN_DIRTY(inode)) { + xfs_ilock(ip, XFS_IOLOCK_SHARED); + lock_flags |= XFS_IOLOCK_SHARED; + error = xfs_flush_pages(ip, 0, -1, fflag, FI_NONE); + if (flags & SYNC_IOWAIT) + xfs_ioend_wait(ip); + } + xfs_ilock(ip, XFS_ILOCK_SHARED); + + if ((flags & SYNC_ATTR) && !xfs_inode_clean(ip)) { + if (flags & SYNC_WAIT) { + xfs_iflock(ip); + if (!xfs_inode_clean(ip)) + error = xfs_iflush(ip, XFS_IFLUSH_SYNC); + else + xfs_ifunlock(ip); + } else if (xfs_iflock_nowait(ip)) { + if (!xfs_inode_clean(ip)) + error = xfs_iflush(ip, XFS_IFLUSH_DELWRI); + else + xfs_ifunlock(ip); + } + } + xfs_iput(ip, lock_flags); + + if (error) + last_error = error; + /* + * bail out if the filesystem is corrupted. + */ + if (error == EFSCORRUPTED) + return XFS_ERROR(error); + + } while (nr_found); + + return last_error; +} + +int +xfs_sync_inodes( + xfs_mount_t *mp, + int flags) +{ + int error; + int last_error; + int i; + int lflags = XFS_LOG_FORCE; + + if (mp->m_flags & XFS_MOUNT_RDONLY) + return 0; + error = 0; + last_error = 0; + + if (flags & SYNC_WAIT) + lflags |= XFS_LOG_SYNC; + + for (i = 0; i < mp->m_sb.sb_agcount; i++) { + if (!mp->m_perag[i].pag_ici_init) + continue; + error = xfs_sync_inodes_ag(mp, i, flags); + if (error) + last_error = error; + if (error == EFSCORRUPTED) + break; + } + if (flags & SYNC_DELWRI) + xfs_log_force(mp, 0, lflags); + + return XFS_ERROR(last_error); +} + +STATIC int +xfs_commit_dummy_trans( + struct xfs_mount *mp, + uint log_flags) +{ + struct xfs_inode *ip = mp->m_rootip; + struct xfs_trans *tp; + int error; + + /* + * Put a dummy transaction in the log to tell recovery + * that all others are OK. + */ + tp = xfs_trans_alloc(mp, XFS_TRANS_DUMMY1); + error = xfs_trans_reserve(tp, 0, XFS_ICHANGE_LOG_RES(mp), 0, 0, 0); + if (error) { + xfs_trans_cancel(tp, 0); + return error; + } + + xfs_ilock(ip, XFS_ILOCK_EXCL); + + xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); + xfs_trans_ihold(tp, ip); + xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); + /* XXX(hch): ignoring the error here.. */ + error = xfs_trans_commit(tp, 0); + + xfs_iunlock(ip, XFS_ILOCK_EXCL); + + xfs_log_force(mp, 0, log_flags); + return 0; +} + +int +xfs_sync_fsdata( + struct xfs_mount *mp, + int flags) +{ + struct xfs_buf *bp; + struct xfs_buf_log_item *bip; + int error = 0; + + /* + * If this is xfssyncd() then only sync the superblock if we can + * lock it without sleeping and it is not pinned. + */ + if (flags & SYNC_BDFLUSH) { + ASSERT(!(flags & SYNC_WAIT)); + + bp = xfs_getsb(mp, XFS_BUF_TRYLOCK); + if (!bp) + goto out; + + bip = XFS_BUF_FSPRIVATE(bp, struct xfs_buf_log_item *); + if (!bip || !xfs_buf_item_dirty(bip) || XFS_BUF_ISPINNED(bp)) + goto out_brelse; + } else { + bp = xfs_getsb(mp, 0); + + /* + * If the buffer is pinned then push on the log so we won't + * get stuck waiting in the write for someone, maybe + * ourselves, to flush the log. + * + * Even though we just pushed the log above, we did not have + * the superblock buffer locked at that point so it can + * become pinned in between there and here. + */ + if (XFS_BUF_ISPINNED(bp)) + xfs_log_force(mp, 0, XFS_LOG_FORCE); + } + + + if (flags & SYNC_WAIT) + XFS_BUF_UNASYNC(bp); + else + XFS_BUF_ASYNC(bp); + + return xfs_bwrite(mp, bp); + + out_brelse: + xfs_buf_relse(bp); + out: + return error; +} + +/* + * When remounting a filesystem read-only or freezing the filesystem, we have + * two phases to execute. This first phase is syncing the data before we + * quiesce the filesystem, and the second is flushing all the inodes out after + * we've waited for all the transactions created by the first phase to + * complete. The second phase ensures that the inodes are written to their + * location on disk rather than just existing in transactions in the log. This + * means after a quiesce there is no log replay required to write the inodes to + * disk (this is the main difference between a sync and a quiesce). + */ +/* + * First stage of freeze - no writers will make progress now we are here, + * so we flush delwri and delalloc buffers here, then wait for all I/O to + * complete. Data is frozen at that point. Metadata is not frozen, + * transactions can still occur here so don't bother flushing the buftarg + * because it'll just get dirty again. + */ +int +xfs_quiesce_data( + struct xfs_mount *mp) +{ + int error; + + /* push non-blocking */ + xfs_sync_inodes(mp, SYNC_DELWRI|SYNC_BDFLUSH); + XFS_QM_DQSYNC(mp, SYNC_BDFLUSH); + xfs_filestream_flush(mp); + + /* push and block */ + xfs_sync_inodes(mp, SYNC_DELWRI|SYNC_WAIT|SYNC_IOWAIT); + XFS_QM_DQSYNC(mp, SYNC_WAIT); + + /* write superblock and hoover up shutdown errors */ + error = xfs_sync_fsdata(mp, 0); + + /* flush data-only devices */ + if (mp->m_rtdev_targp) + XFS_bflush(mp->m_rtdev_targp); + + return error; +} + +STATIC void +xfs_quiesce_fs( + struct xfs_mount *mp) +{ + int count = 0, pincount; + + xfs_flush_buftarg(mp->m_ddev_targp, 0); + xfs_reclaim_inodes(mp, 0, XFS_IFLUSH_DELWRI_ELSE_ASYNC); + + /* + * This loop must run at least twice. The first instance of the loop + * will flush most meta data but that will generate more meta data + * (typically directory updates). Which then must be flushed and + * logged before we can write the unmount record. + */ + do { + xfs_sync_inodes(mp, SYNC_ATTR|SYNC_WAIT); + pincount = xfs_flush_buftarg(mp->m_ddev_targp, 1); + if (!pincount) { + delay(50); + count++; + } + } while (count < 2); +} + +/* + * Second stage of a quiesce. The data is already synced, now we have to take + * care of the metadata. New transactions are already blocked, so we need to + * wait for any remaining transactions to drain out before proceding. + */ +void +xfs_quiesce_attr( + struct xfs_mount *mp) +{ + int error = 0; + + /* wait for all modifications to complete */ + while (atomic_read(&mp->m_active_trans) > 0) + delay(100); + + /* flush inodes and push all remaining buffers out to disk */ + xfs_quiesce_fs(mp); + + ASSERT_ALWAYS(atomic_read(&mp->m_active_trans) == 0); + + /* Push the superblock and write an unmount record */ + error = xfs_log_sbcount(mp, 1); + if (error) + xfs_fs_cmn_err(CE_WARN, mp, + "xfs_attr_quiesce: failed to log sb changes. " + "Frozen image may not be consistent."); + xfs_log_unmount_write(mp); + xfs_unmountfs_writesb(mp); +} + +/* + * Enqueue a work item to be picked up by the vfs xfssyncd thread. + * Doing this has two advantages: + * - It saves on stack space, which is tight in certain situations + * - It can be used (with care) as a mechanism to avoid deadlocks. + * Flushing while allocating in a full filesystem requires both. + */ +STATIC void +xfs_syncd_queue_work( + struct xfs_mount *mp, + void *data, + void (*syncer)(struct xfs_mount *, void *)) +{ + struct bhv_vfs_sync_work *work; + + work = kmem_alloc(sizeof(struct bhv_vfs_sync_work), KM_SLEEP); + INIT_LIST_HEAD(&work->w_list); + work->w_syncer = syncer; + work->w_data = data; + work->w_mount = mp; + spin_lock(&mp->m_sync_lock); + list_add_tail(&work->w_list, &mp->m_sync_list); + spin_unlock(&mp->m_sync_lock); + wake_up_process(mp->m_sync_task); +} + +/* + * Flush delayed allocate data, attempting to free up reserved space + * from existing allocations. At this point a new allocation attempt + * has failed with ENOSPC and we are in the process of scratching our + * heads, looking about for more room... + */ +STATIC void +xfs_flush_inode_work( + struct xfs_mount *mp, + void *arg) +{ + struct inode *inode = arg; + filemap_flush(inode->i_mapping); + iput(inode); +} + +void +xfs_flush_inode( + xfs_inode_t *ip) +{ + struct inode *inode = VFS_I(ip); + + igrab(inode); + xfs_syncd_queue_work(ip->i_mount, inode, xfs_flush_inode_work); + delay(msecs_to_jiffies(500)); +} + +/* + * This is the "bigger hammer" version of xfs_flush_inode_work... + * (IOW, "If at first you don't succeed, use a Bigger Hammer"). + */ +STATIC void +xfs_flush_device_work( + struct xfs_mount *mp, + void *arg) +{ + struct inode *inode = arg; + sync_blockdev(mp->m_super->s_bdev); + iput(inode); +} + +void +xfs_flush_device( + xfs_inode_t *ip) +{ + struct inode *inode = VFS_I(ip); + + igrab(inode); + xfs_syncd_queue_work(ip->i_mount, inode, xfs_flush_device_work); + delay(msecs_to_jiffies(500)); + xfs_log_force(ip->i_mount, (xfs_lsn_t)0, XFS_LOG_FORCE|XFS_LOG_SYNC); +} + +/* + * Every sync period we need to unpin all items, reclaim inodes, sync + * quota and write out the superblock. We might need to cover the log + * to indicate it is idle. + */ +STATIC void +xfs_sync_worker( + struct xfs_mount *mp, + void *unused) +{ + int error; + + if (!(mp->m_flags & XFS_MOUNT_RDONLY)) { + xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE); + xfs_reclaim_inodes(mp, 0, XFS_IFLUSH_DELWRI_ELSE_ASYNC); + /* dgc: errors ignored here */ + error = XFS_QM_DQSYNC(mp, SYNC_BDFLUSH); + error = xfs_sync_fsdata(mp, SYNC_BDFLUSH); + if (xfs_log_need_covered(mp)) + error = xfs_commit_dummy_trans(mp, XFS_LOG_FORCE); + } + mp->m_sync_seq++; + wake_up(&mp->m_wait_single_sync_task); +} + +STATIC int +xfssyncd( + void *arg) +{ + struct xfs_mount *mp = arg; + long timeleft; + bhv_vfs_sync_work_t *work, *n; + LIST_HEAD (tmp); + + set_freezable(); + timeleft = xfs_syncd_centisecs * msecs_to_jiffies(10); + for (;;) { + timeleft = schedule_timeout_interruptible(timeleft); + /* swsusp */ + try_to_freeze(); + if (kthread_should_stop() && list_empty(&mp->m_sync_list)) + break; + + spin_lock(&mp->m_sync_lock); + /* + * We can get woken by laptop mode, to do a sync - + * that's the (only!) case where the list would be + * empty with time remaining. + */ + if (!timeleft || list_empty(&mp->m_sync_list)) { + if (!timeleft) + timeleft = xfs_syncd_centisecs * + msecs_to_jiffies(10); + INIT_LIST_HEAD(&mp->m_sync_work.w_list); + list_add_tail(&mp->m_sync_work.w_list, + &mp->m_sync_list); + } + list_for_each_entry_safe(work, n, &mp->m_sync_list, w_list) + list_move(&work->w_list, &tmp); + spin_unlock(&mp->m_sync_lock); + + list_for_each_entry_safe(work, n, &tmp, w_list) { + (*work->w_syncer)(mp, work->w_data); + list_del(&work->w_list); + if (work == &mp->m_sync_work) + continue; + kmem_free(work); + } + } + + return 0; +} + +int +xfs_syncd_init( + struct xfs_mount *mp) +{ + mp->m_sync_work.w_syncer = xfs_sync_worker; + mp->m_sync_work.w_mount = mp; + mp->m_sync_task = kthread_run(xfssyncd, mp, "xfssyncd"); + if (IS_ERR(mp->m_sync_task)) + return -PTR_ERR(mp->m_sync_task); + return 0; +} + +void +xfs_syncd_stop( + struct xfs_mount *mp) +{ + kthread_stop(mp->m_sync_task); +} + +int +xfs_reclaim_inode( + xfs_inode_t *ip, + int locked, + int sync_mode) +{ + xfs_perag_t *pag = xfs_get_perag(ip->i_mount, ip->i_ino); + + /* The hash lock here protects a thread in xfs_iget_core from + * racing with us on linking the inode back with a vnode. + * Once we have the XFS_IRECLAIM flag set it will not touch + * us. + */ + write_lock(&pag->pag_ici_lock); + spin_lock(&ip->i_flags_lock); + if (__xfs_iflags_test(ip, XFS_IRECLAIM) || + !__xfs_iflags_test(ip, XFS_IRECLAIMABLE)) { + spin_unlock(&ip->i_flags_lock); + write_unlock(&pag->pag_ici_lock); + if (locked) { + xfs_ifunlock(ip); + xfs_iunlock(ip, XFS_ILOCK_EXCL); + } + return 1; + } + __xfs_iflags_set(ip, XFS_IRECLAIM); + spin_unlock(&ip->i_flags_lock); + write_unlock(&pag->pag_ici_lock); + xfs_put_perag(ip->i_mount, pag); + + /* + * If the inode is still dirty, then flush it out. If the inode + * is not in the AIL, then it will be OK to flush it delwri as + * long as xfs_iflush() does not keep any references to the inode. + * We leave that decision up to xfs_iflush() since it has the + * knowledge of whether it's OK to simply do a delwri flush of + * the inode or whether we need to wait until the inode is + * pulled from the AIL. + * We get the flush lock regardless, though, just to make sure + * we don't free it while it is being flushed. + */ + if (!locked) { + xfs_ilock(ip, XFS_ILOCK_EXCL); + xfs_iflock(ip); + } + + /* + * In the case of a forced shutdown we rely on xfs_iflush() to + * wait for the inode to be unpinned before returning an error. + */ + if (!is_bad_inode(VFS_I(ip)) && xfs_iflush(ip, sync_mode) == 0) { + /* synchronize with xfs_iflush_done */ + xfs_iflock(ip); + xfs_ifunlock(ip); + } + + xfs_iunlock(ip, XFS_ILOCK_EXCL); + xfs_ireclaim(ip); + return 0; +} + +/* + * We set the inode flag atomically with the radix tree tag. + * Once we get tag lookups on the radix tree, this inode flag + * can go away. + */ +void +xfs_inode_set_reclaim_tag( + xfs_inode_t *ip) +{ + xfs_mount_t *mp = ip->i_mount; + xfs_perag_t *pag = xfs_get_perag(mp, ip->i_ino); + + read_lock(&pag->pag_ici_lock); + spin_lock(&ip->i_flags_lock); + radix_tree_tag_set(&pag->pag_ici_root, + XFS_INO_TO_AGINO(mp, ip->i_ino), XFS_ICI_RECLAIM_TAG); + __xfs_iflags_set(ip, XFS_IRECLAIMABLE); + spin_unlock(&ip->i_flags_lock); + read_unlock(&pag->pag_ici_lock); + xfs_put_perag(mp, pag); +} + +void +__xfs_inode_clear_reclaim_tag( + xfs_mount_t *mp, + xfs_perag_t *pag, + xfs_inode_t *ip) +{ + radix_tree_tag_clear(&pag->pag_ici_root, + XFS_INO_TO_AGINO(mp, ip->i_ino), XFS_ICI_RECLAIM_TAG); +} + +void +xfs_inode_clear_reclaim_tag( + xfs_inode_t *ip) +{ + xfs_mount_t *mp = ip->i_mount; + xfs_perag_t *pag = xfs_get_perag(mp, ip->i_ino); + + read_lock(&pag->pag_ici_lock); + spin_lock(&ip->i_flags_lock); + __xfs_inode_clear_reclaim_tag(mp, pag, ip); + spin_unlock(&ip->i_flags_lock); + read_unlock(&pag->pag_ici_lock); + xfs_put_perag(mp, pag); +} + + +STATIC void +xfs_reclaim_inodes_ag( + xfs_mount_t *mp, + int ag, + int noblock, + int mode) +{ + xfs_inode_t *ip = NULL; + xfs_perag_t *pag = &mp->m_perag[ag]; + int nr_found; + uint32_t first_index; + int skipped; + +restart: + first_index = 0; + skipped = 0; + do { + /* + * use a gang lookup to find the next inode in the tree + * as the tree is sparse and a gang lookup walks to find + * the number of objects requested. + */ + read_lock(&pag->pag_ici_lock); + nr_found = radix_tree_gang_lookup_tag(&pag->pag_ici_root, + (void**)&ip, first_index, 1, + XFS_ICI_RECLAIM_TAG); + + if (!nr_found) { + read_unlock(&pag->pag_ici_lock); + break; + } + + /* + * Update the index for the next lookup. Catch overflows + * into the next AG range which can occur if we have inodes + * in the last block of the AG and we are currently + * pointing to the last inode. + */ + first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1); + if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino)) { + read_unlock(&pag->pag_ici_lock); + break; + } + + /* ignore if already under reclaim */ + if (xfs_iflags_test(ip, XFS_IRECLAIM)) { + read_unlock(&pag->pag_ici_lock); + continue; + } + + if (noblock) { + if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL)) { + read_unlock(&pag->pag_ici_lock); + continue; + } + if (xfs_ipincount(ip) || + !xfs_iflock_nowait(ip)) { + xfs_iunlock(ip, XFS_ILOCK_EXCL); + read_unlock(&pag->pag_ici_lock); + continue; + } + } + read_unlock(&pag->pag_ici_lock); + + /* + * hmmm - this is an inode already in reclaim. Do + * we even bother catching it here? + */ + if (xfs_reclaim_inode(ip, noblock, mode)) + skipped++; + } while (nr_found); + + if (skipped) { + delay(1); + goto restart; + } + return; + +} + +int +xfs_reclaim_inodes( + xfs_mount_t *mp, + int noblock, + int mode) +{ + int i; + + for (i = 0; i < mp->m_sb.sb_agcount; i++) { + if (!mp->m_perag[i].pag_ici_init) + continue; + xfs_reclaim_inodes_ag(mp, i, noblock, mode); + } + return 0; +} + + |