From: Mingming Cao This patch is trying to do lazy discard: keep the old reservation window temporarilly until we find the new reservation window, only do remove/add if the new reservation window locate different than the old one. (The current reservation code will discard the old one first,then search the new one). Two reasons: a. If the ext3_find_goal() does a good job, the reservation windows on the list should not very close to each other. So an inode's new reservation window is likely located just next to it's old one, it's position in the whole list is unchanged, no need to do remove and then add the new one to the list in the same location. Just update the start block and end block. b. If we failed to find a new reservation in the goal group and move on the search to the next group, having the old reservation around temporally could allow us to search the list directly after the old window. Otherwise we lost where we were and has to start from the beginning of the list. Eventually the old window will be discard when we found a new one. DESC ext3 discard reservation in last iput fix patch EDESC From: Mingming Cao ext3_discard_reservation() should not be called on every iput(). Now it is moved to ext3_delete_inode(), so it is only called on the last iput(). DESC Fix lazy reservation discard EDESC ->delete_inode() is only called when the inode is being deleted. So we're leaving inodes on the reservation list when they are reclaimed by the VM. So take them off the reservation list in ->clear_inode instead. DESC ext3 reservations: bad_inode fix EDESC From: Mingming Cao Thanks Badari!! The easiest fix is checking whether it is a bad inode in ext3_clear_inode() (like what ext2_put_inode() does): DESC ext3 reservation discard race fix EDESC From: Mingming Cao This should fix a reservation window race between multiple processes when one process closed the file while another one is in the middle of block allocation using the inode's reservation window. reservation window should be discard on the last writer on the inode, not the last writer on the filp. Signed-off-by: Andrew Morton --- 25-akpm/fs/ext3/balloc.c | 22 +++++++++++++++------- 25-akpm/fs/ext3/file.c | 4 +++- 25-akpm/fs/ext3/inode.c | 13 ------------- 25-akpm/fs/ext3/super.c | 11 ++++------- 4 files changed, 22 insertions(+), 28 deletions(-) diff -puN fs/ext3/balloc.c~ext3-lazy-discard-reservation-window-patch fs/ext3/balloc.c --- 25/fs/ext3/balloc.c~ext3-lazy-discard-reservation-window-patch Wed Jun 16 16:54:22 2004 +++ 25-akpm/fs/ext3/balloc.c Wed Jun 16 16:54:22 2004 @@ -726,7 +726,7 @@ static int alloc_new_reservation(struct start_block = goal + group_first_block; size = atomic_read(&my_rsv->rsv_goal_size); - /* if we have a old reservation, discard it first */ + /* if we have a old reservation, start the search from the old rsv */ if (!rsv_is_empty(my_rsv)) { /* * if the old reservation is cross group boundary @@ -748,8 +748,7 @@ static int alloc_new_reservation(struct /* remember where we are before we discard the old one */ if (my_rsv->rsv_end + 1 > start_block) start_block = my_rsv->rsv_end + 1; - search_head = list_entry(my_rsv->rsv_list.prev, - struct reserve_window, rsv_list); + search_head = my_rsv; if ((my_rsv->rsv_alloc_hit > (my_rsv->rsv_end - my_rsv->rsv_start + 1) / 2)) { /* * if we previously allocation hit ration is greater than half @@ -761,7 +760,6 @@ static int alloc_new_reservation(struct size = EXT3_MAX_RESERVE_BLOCKS; atomic_set(&my_rsv->rsv_goal_size, size); } - rsv_window_remove(my_rsv); } else { /* @@ -828,9 +826,16 @@ retry: found_rsv_window: /* * great! the reservable space contains some free blocks. - * Insert it to the list. - */ - rsv_window_add(my_rsv, prev_rsv); + * if the search returns that we should add the new + * window just next to where the old window, we don't + * need to remove the old window first then add it to the + * same place, just update the new start and new end. + */ + if (my_rsv != prev_rsv) { + if (!rsv_is_empty(my_rsv)) + rsv_window_remove(my_rsv); + rsv_window_add(my_rsv, prev_rsv); + } my_rsv->rsv_start = reservable_space_start; my_rsv->rsv_end = my_rsv->rsv_start + size - 1; return 0; /* succeed */ @@ -932,6 +937,9 @@ ext3_try_to_allocate_with_rsv(struct sup if (!goal_in_my_reservation(my_rsv, goal, group, sb)) goal = -1; } + if ((my_rsv->rsv_start >= group_first_block + EXT3_BLOCKS_PER_GROUP(sb)) + || (my_rsv->rsv_end < group_first_block)) + BUG(); ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, goal, my_rsv); if (ret >= 0) diff -puN fs/ext3/inode.c~ext3-lazy-discard-reservation-window-patch fs/ext3/inode.c --- 25/fs/ext3/inode.c~ext3-lazy-discard-reservation-window-patch Wed Jun 16 16:54:22 2004 +++ 25-akpm/fs/ext3/inode.c Wed Jun 16 16:54:22 2004 @@ -177,19 +177,6 @@ static int ext3_journal_test_restart(han } /* - * Called at each iput() - * - * The inode may be "bad" if ext3_read_inode() saw an error from - * ext3_get_inode(), so we need to check that to avoid freeing random disk - * blocks. - */ -void ext3_put_inode(struct inode *inode) -{ - if (!is_bad_inode(inode)) - ext3_discard_reservation(inode); -} - -/* * Called at the last iput() if i_nlink is zero. */ void ext3_delete_inode (struct inode * inode) diff -puN fs/ext3/super.c~ext3-lazy-discard-reservation-window-patch fs/ext3/super.c --- 25/fs/ext3/super.c~ext3-lazy-discard-reservation-window-patch Wed Jun 16 16:54:22 2004 +++ 25-akpm/fs/ext3/super.c Wed Jun 16 16:54:44 2004 @@ -493,10 +493,9 @@ static void destroy_inodecache(void) printk(KERN_INFO "ext3_inode_cache: not all structures were freed\n"); } -#ifdef CONFIG_EXT3_FS_POSIX_ACL - static void ext3_clear_inode(struct inode *inode) { +#ifdef CONFIG_EXT3_FS_POSIX_ACL if (EXT3_I(inode)->i_acl && EXT3_I(inode)->i_acl != EXT3_ACL_NOT_CACHED) { posix_acl_release(EXT3_I(inode)->i_acl); @@ -507,11 +506,10 @@ static void ext3_clear_inode(struct inod posix_acl_release(EXT3_I(inode)->i_default_acl); EXT3_I(inode)->i_default_acl = EXT3_ACL_NOT_CACHED; } -} - -#else -# define ext3_clear_inode NULL #endif + if (!is_bad_inode(inode)) + ext3_discard_reservation(inode); +} #ifdef CONFIG_QUOTA @@ -561,7 +559,6 @@ static struct super_operations ext3_sops .read_inode = ext3_read_inode, .write_inode = ext3_write_inode, .dirty_inode = ext3_dirty_inode, - .put_inode = ext3_put_inode, .delete_inode = ext3_delete_inode, .put_super = ext3_put_super, .write_super = ext3_write_super, diff -puN fs/ext3/file.c~ext3-lazy-discard-reservation-window-patch fs/ext3/file.c --- 25/fs/ext3/file.c~ext3-lazy-discard-reservation-window-patch Wed Jun 16 16:54:58 2004 +++ 25-akpm/fs/ext3/file.c Wed Jun 16 16:54:58 2004 @@ -33,7 +33,9 @@ */ static int ext3_release_file (struct inode * inode, struct file * filp) { - if (filp->f_mode & FMODE_WRITE) + /* if we are the last writer on the inode, drop the block reservation */ + if ((filp->f_mode & FMODE_WRITE) && + (atomic_read(&inode->i_writecount) == 1)) ext3_discard_reservation(inode); if (is_dx(inode) && filp->private_data) ext3_htree_free_dir_info(filp->private_data); _