forked from luck/tmp_suning_uos_patched
e599b3253c
While xfs_buftarg_shrink() is freeing buffers from the dispose list (filled with buffers from lru list), there is a possibility to have xfs_buf_stale() racing with it, and removing buffers from dispose list before xfs_buftarg_shrink() does it. This happens because xfs_buftarg_shrink() handle the dispose list without locking and the test condition in xfs_buf_stale() checks for the buffer being in *any* list: if (!list_empty(&bp->b_lru)) If the buffer happens to be on dispose list, this causes the buffer counter of lru list (btp->bt_lru_nr) to be decremented twice (once in xfs_buftarg_shrink() and another in xfs_buf_stale()) causing a wrong account usage of the lru list. This may cause xfs_buftarg_shrink() to return a wrong value to the memory shrinker shrink_slab(), and such account error may also cause an underflowed value to be returned; since the counter is lower than the current number of items in the lru list, a decrement may happen when the counter is 0, causing an underflow on the counter. The fix uses a new flag field (and a new buffer flag) to serialize buffer handling during the shrink process. The new flag field has been designed to use btp->bt_lru_lock/unlock instead of xfs_buf_lock/unlock mechanism. dchinner, sandeen, aquini and aris also deserve credits for this. Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com> |
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| .. | ||
| Kconfig | ||
| kmem.c | ||
| kmem.h | ||
| Makefile | ||
| mrlock.h | ||
| time.h | ||
| uuid.c | ||
| uuid.h | ||
| xfs_acl.c | ||
| xfs_acl.h | ||
| xfs_ag.h | ||
| xfs_alloc_btree.c | ||
| xfs_alloc_btree.h | ||
| xfs_alloc.c | ||
| xfs_alloc.h | ||
| xfs_aops.c | ||
| xfs_aops.h | ||
| xfs_attr_leaf.c | ||
| xfs_attr_leaf.h | ||
| xfs_attr_sf.h | ||
| xfs_attr.c | ||
| xfs_attr.h | ||
| xfs_bit.c | ||
| xfs_bit.h | ||
| xfs_bmap_btree.c | ||
| xfs_bmap_btree.h | ||
| xfs_bmap.c | ||
| xfs_bmap.h | ||
| xfs_btree.c | ||
| xfs_btree.h | ||
| xfs_buf_item.c | ||
| xfs_buf_item.h | ||
| xfs_buf.c | ||
| xfs_buf.h | ||
| xfs_da_btree.c | ||
| xfs_da_btree.h | ||
| xfs_dfrag.c | ||
| xfs_dfrag.h | ||
| xfs_dinode.h | ||
| xfs_dir2_block.c | ||
| xfs_dir2_data.c | ||
| xfs_dir2_format.h | ||
| xfs_dir2_leaf.c | ||
| xfs_dir2_node.c | ||
| xfs_dir2_priv.h | ||
| xfs_dir2_sf.c | ||
| xfs_dir2.c | ||
| xfs_dir2.h | ||
| xfs_discard.c | ||
| xfs_discard.h | ||
| xfs_dquot_item.c | ||
| xfs_dquot_item.h | ||
| xfs_dquot.c | ||
| xfs_dquot.h | ||
| xfs_error.c | ||
| xfs_error.h | ||
| xfs_export.c | ||
| xfs_export.h | ||
| xfs_extent_busy.c | ||
| xfs_extent_busy.h | ||
| xfs_extfree_item.c | ||
| xfs_extfree_item.h | ||
| xfs_file.c | ||
| xfs_filestream.c | ||
| xfs_filestream.h | ||
| xfs_fs_subr.c | ||
| xfs_fs.h | ||
| xfs_fsops.c | ||
| xfs_fsops.h | ||
| xfs_globals.c | ||
| xfs_ialloc_btree.c | ||
| xfs_ialloc_btree.h | ||
| xfs_ialloc.c | ||
| xfs_ialloc.h | ||
| xfs_iget.c | ||
| xfs_inode_item.c | ||
| xfs_inode_item.h | ||
| xfs_inode.c | ||
| xfs_inode.h | ||
| xfs_inum.h | ||
| xfs_ioctl32.c | ||
| xfs_ioctl32.h | ||
| xfs_ioctl.c | ||
| xfs_ioctl.h | ||
| xfs_iomap.c | ||
| xfs_iomap.h | ||
| xfs_iops.c | ||
| xfs_iops.h | ||
| xfs_itable.c | ||
| xfs_itable.h | ||
| xfs_linux.h | ||
| xfs_log_cil.c | ||
| xfs_log_priv.h | ||
| xfs_log_recover.c | ||
| xfs_log_recover.h | ||
| xfs_log.c | ||
| xfs_log.h | ||
| xfs_message.c | ||
| xfs_message.h | ||
| xfs_mount.c | ||
| xfs_mount.h | ||
| xfs_mru_cache.c | ||
| xfs_mru_cache.h | ||
| xfs_qm_bhv.c | ||
| xfs_qm_syscalls.c | ||
| xfs_qm.c | ||
| xfs_qm.h | ||
| xfs_quota_priv.h | ||
| xfs_quota.h | ||
| xfs_quotaops.c | ||
| xfs_rename.c | ||
| xfs_rtalloc.c | ||
| xfs_rtalloc.h | ||
| xfs_sb.h | ||
| xfs_stats.c | ||
| xfs_stats.h | ||
| xfs_super.c | ||
| xfs_super.h | ||
| xfs_sync.c | ||
| xfs_sync.h | ||
| xfs_sysctl.c | ||
| xfs_sysctl.h | ||
| xfs_trace.c | ||
| xfs_trace.h | ||
| xfs_trans_ail.c | ||
| xfs_trans_buf.c | ||
| xfs_trans_dquot.c | ||
| xfs_trans_extfree.c | ||
| xfs_trans_inode.c | ||
| xfs_trans_priv.h | ||
| xfs_trans_space.h | ||
| xfs_trans.c | ||
| xfs_trans.h | ||
| xfs_types.h | ||
| xfs_utils.c | ||
| xfs_utils.h | ||
| xfs_vnode.h | ||
| xfs_vnodeops.c | ||
| xfs_vnodeops.h | ||
| xfs_xattr.c | ||
| xfs.h | ||