diff options
| -rw-r--r-- | fs/xfs/xfs_iget.c | 51 |
1 files changed, 50 insertions, 1 deletions
diff --git a/fs/xfs/xfs_iget.c b/fs/xfs/xfs_iget.c index 3a0ba1dfd0e..d3da00045f2 100644 --- a/fs/xfs/xfs_iget.c +++ b/fs/xfs/xfs_iget.c @@ -136,6 +136,40 @@ xfs_chash_free(xfs_mount_t *mp) } /* + * Try to move an inode to the front of its hash list if possible + * (and if its not there already). Called right after obtaining + * the list version number and then dropping the read_lock on the + * hash list in question (which is done right after looking up the + * inode in question...). + */ +STATIC void +xfs_ihash_promote( + xfs_ihash_t *ih, + xfs_inode_t *ip, + ulong version) +{ + xfs_inode_t *iq; + + if ((ip->i_prevp != &ih->ih_next) && write_trylock(&ih->ih_lock)) { + if (likely(version == ih->ih_version)) { + /* remove from list */ + if ((iq = ip->i_next)) { + iq->i_prevp = ip->i_prevp; + } + *ip->i_prevp = iq; + + /* insert at list head */ + iq = ih->ih_next; + iq->i_prevp = &ip->i_next; + ip->i_next = iq; + ip->i_prevp = &ih->ih_next; + ih->ih_next = ip; + } + write_unlock(&ih->ih_lock); + } +} + +/* * Look up an inode by number in the given file system. * The inode is looked up in the hash table for the file system * represented by the mount point parameter mp. Each bucket of @@ -229,7 +263,9 @@ again: XFS_STATS_INC(xs_ig_found); ip->i_flags &= ~XFS_IRECLAIMABLE; + version = ih->ih_version; read_unlock(&ih->ih_lock); + xfs_ihash_promote(ih, ip, version); XFS_MOUNT_ILOCK(mp); list_del_init(&ip->i_reclaim); @@ -259,8 +295,15 @@ again: inode_vp, vp); } + /* + * Inode cache hit: if ip is not at the front of + * its hash chain, move it there now. + * Do this with the lock held for update, but + * do statistics after releasing the lock. + */ + version = ih->ih_version; read_unlock(&ih->ih_lock); - + xfs_ihash_promote(ih, ip, version); XFS_STATS_INC(xs_ig_found); finish_inode: @@ -547,6 +590,7 @@ xfs_inode_incore(xfs_mount_t *mp, { xfs_ihash_t *ih; xfs_inode_t *ip; + ulong version; ih = XFS_IHASH(mp, ino); read_lock(&ih->ih_lock); @@ -554,11 +598,15 @@ xfs_inode_incore(xfs_mount_t *mp, if (ip->i_ino == ino) { /* * If we find it and tp matches, return it. + * Also move it to the front of the hash list + * if we find it and it is not already there. * Otherwise break from the loop and return * NULL. */ if (ip->i_transp == tp) { + version = ih->ih_version; read_unlock(&ih->ih_lock); + xfs_ihash_promote(ih, ip, version); return (ip); } break; @@ -685,6 +733,7 @@ xfs_iextract( iq->i_prevp = ip->i_prevp; } *ip->i_prevp = iq; + ih->ih_version++; write_unlock(&ih->ih_lock); /* |