- 19 Oct, 2011 40 commits
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Josef Bacik authored
In __unlink_start_trans() if we don't have enough room for a reservation we will check to see if the unlink will free up space. If it does that's great, but we will still could add an orphan item, so we need to reserve enough space to add the orphan item. Do this and migrate the space the global reserve so it all works out right. Thanks, Signed-off-by:Josef Bacik <josef@redhat.com>
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Josef Bacik authored
We started setting trans->block_rsv = NULL to allow the delayed refs flushing stuff to use the right block_rsv and then just made btrfs_trans_release_metadata() unconditionally use the trans block rsv. The problem with this is we need to reserve some space in the transaction and then migrate it to the global block rsv, so we need to be able to free that out properly. So instead just move btrfs_trans_release_metadata() before the delayed ref flushing and use trans->block_rsv for the freeing. Thanks, Signed-off-by: -
Josef Bacik authored
Currently we only allow a maximum of 2 megabytes of pages to be flushed at a time. This was ok before, but now we have overcommit which will screw us in a heartbeat if we are quickly filling the disk. So instead pick either 2 megabytes or the number of pages we need to reclaim to be safe again, which ever is larger. Thanks, Signed-off-by: -
Josef Bacik authored
The only way we actually reclaim delalloc space is waiting for the IO to completely finish. Usually we kick off a bunch of IO and wait for a little bit and hope we can make our reservation, and usually this works out pretty well. With overcommit however we can get seriously underwater if we're filling up the disk quickly, so we need to be able to force the delalloc shrinker to wait for the ordered IO to finish to give us a better chance of actually reclaiming enough space to get our reservation. Thanks, Signed-off-by: -
Josef Bacik authored
Before the only reason to commit the transaction to recover space in reserve_metadata_bytes() was if there were enough pinned_bytes to satisfy our reservation. But now we have the delayed inode stuff which will hold it's reservations until we commit the transaction. So say we max out our reservation by creating a bunch of files but don't have any pinned bytes we will ENOSPC out early even though we could commit the transaction and get that space back. So now just unconditionally commit the transaction since currently there is no way to know how much metadata space is being reserved by delayed inode stuff. Thanks, Signed-off-by: -
Josef Bacik authored
Recently I changed the xattr stuff to unconditionally set the xattr first in case the xattr didn't exist yet. This has introduced a regression when setting an xattr that already exists with a large value. If we find the key we are looking for split_leaf will assume that we're extending that item. The problem is the size we pass down to btrfs_search_slot includes the size of the item already, so if we have the largest xattr we can possibly have plus the size of the xattr item plus the xattr item that btrfs_search_slot we'd overflow the leaf. Thankfully this is not what we're doing, but split_leaf doesn't know this so it just returns EOVERFLOW. So in the xattr code we need to check and see if we got back EOVERFLOW and treat it like EEXIST since that's really what happened. Thanks, Signed-off-by: -
Josef Bacik authored
Our unlink reservations were a bit much, we were reserving 10 and I only count 8 possible items we're touching, so comment what we're reserving for and fix the count value. Thanks, Signed-off-by: -
Josef Bacik authored
I noticed recently that my overcommit patch was causing one of my enospc tests to fail 25% of the time with early ENOSPC. This is because my overcommit patch was letting us go way over board, but it wasn't waiting long enough to let the delalloc shrinker do it's job. The problem is we just start writeback and wait a little bit hoping we flush enough, but we only free up delalloc space by having the writes complete all the way. We do this by waiting for ordered extents, which we do but only if we already free'd enough for the reservation, which isn't right, we should flush ordered extents if we didn't reclaim enough in case that will push us over the edge. With this patch I've not seen a failure in this enospc test after running it in a loop for an hour. Thanks, Signed-off-by: -
Josef Bacik authored
Yeah yeah I know this is how we used to do it and then I changed it, but damnit I'm changing it back. The fact is that writing out checksums will modify metadata, which could cause us to dirty a block group we've already written out, so we have to truncate it and all of it's checksums and re-write it which will write new checksums which could dirty a blockg roup that has already been written and you see where I'm going with this? This can cause unmount or really anything that depends on a transaction to commit to take it's sweet damned time to happen. So go back to the way it was, only this time we're specifically setting NODATACOW because we can't go through the COW pathway anyway and we're doing our own built-in cow'ing by truncating the free space cache. The other new thing is once we truncate the old cache and preallocate the new space, we don't need to do that song and dance at all for the rest of the transaction, we can just overwrite the existing space with the new cache if the block group changes for whatever reason, and the NODATACOW will let us do this fine. So keep track of which transaction we last cleared our cache in and if we cleared it in this transaction just say we're all setup and carry on. This survives xfstests and stress.sh. The inode cache will continue to use the normal csum infrastructure since it only gets written once and there will be no more modifications to the fs tree in a transaction commit. Signed-off-by: -
Josef Bacik authored
My overcommit stuff can be a little racy when we're filling up the disk with fs_mark and we overcommit into things that quickly get used up for data. So use num_bytes to see if we have enough available space so we're less likely to overcommit ourselves out of the ability to make reservations. Thanks, Signed-off-by: -
Josef Bacik authored
We need to check the return value of filemap_write_and_wait in the space cache writeout code. Also don't set the inode's generation until we're sure nothing else is going to fail. Thanks, Signed-off-by: -
Josef Bacik authored
In writing and reading the space cache we have one big loop that keeps track of which page we are on and then a bunch of sizeable loops underneath this big loop to try and read/write out properly. Especially in the write case this makes things hugely complicated and hard to follow, and makes our error checking and recovery equally as complex. So add a io_ctl struct with a bunch of helpers to keep track of the pages we have, where we are, if we have enough space etc. This unifies how we deal with the pages we're writing and keeps all the messy tracking internal. This allows us to kill the big loops in both the read and write case and makes reviewing and chaning the write and read paths much simpler. I've run xfstests and stress.sh on this code and it survives. Thanks, Signed-off-by: -
Josef Bacik authored
I noticed a slight bug where we will not bother writing out the block group cache's space cache if it's space tree is empty. Since it could have a cluster or pinned extents that need to be written out this is just not a valid test. Thanks, Signed-off-by: -
Josef Bacik authored
Some users have requested this and I've found I needed a way to disable cache loading without actually clearing the cache, so introduce the no_space_cache option. Before we check the super blocks cache generation field and if it was populated we always turned space caching on. Now we check this and set the space cache option on, and then parse the mount options so that if we want it off it get's turned off. Then we check the mount option all the places we do the caching work instead of checking the super's cache generation. This makes things more consistent and lets us turn space caching off. Thanks, Signed-off-by: -
Josef Bacik authored
Xfstests 79 was failing because we were inheriting the S_APPEND flag when we weren't supposed to. There isn't any specific documentation on this so I'm taking the test as the standard of how things work, and having S_APPEND set on a directory doesn't mean that S_APPEND gets inherited by its children according to this test. So only inherit btrfs specific things. This will let us set compress/nocompress on specific directories and everything in the directories will inherit this flag, same with nodatacow. With this patch test 79 passes. Thanks, Signed-off-by: -
Josef Bacik authored
One of the things that kills us is the fact that our ENOSPC reservations are horribly over the top in most normal cases. There isn't too much that can be done about this because when we are completely full we really need them to work like this so we don't under reserve. However if there is plenty of unallocated chunks on the disk we can use that to gauge how much we can overcommit. So this patch adds chunk free space accounting so we always know how much unallocated space we have. Then if we fail to make a reservation within our allocated space, check to see if we can overcommit. In the normal flushing case (like with delalloc metadata reservations) we'll take the free space and divide it by 2 if our metadata profile is setup for DUP or any of those, and then divide it by 8 to make sure we don't overcommit too much. Then if we're in a non-flushing case (we really need this reservation now!) we only limit ourselves to half of the free space. This makes this fio test [torrent] filename=torrent-test rw=randwrite size=4g ioengine=sync directory=/mnt/btrfs-test go from taking around 45 minutes to 10 seconds on my freshly formatted 3 TiB file system. This doesn't seem to break my other enospc tests, but could really use some more testing as this is a super scary change. Thanks, Signed-off-by: -
Josef Bacik authored
I noticed while running xfstests 83 that if we didn't have enough space to delete our inode the orphan cleanup would just loop. This is because it keeps finding the same orphan item and keeps trying to kill it but can't because we don't get an error back from iput for deleting the inode. So keep track of the last guy we tried to kill, if it's the same as the one we're trying to kill currently we know we are having problems and can just error out. I don't have a way to test this so look hard and make sure it's right. Thanks, Signed-off-by: -
Josef Bacik authored
Xfstests 83 really stresses our ENOSPC since it uses a 100mb fs which ends up with the mixed block group stuff. Because of this we can run into a situation where we don't have enough space to delete inodes, or even worse we can't free the inodes when we next mount the fs which causes the orphan code to lose its mind. So if we fail to make our reservation, steal from the global reserve. The global reserve will end up taking up the entire rest of the free space on the fs in this worst case so there really is no other option. With this patch test 83 doesn't freak out. Thanks, Signed-off-by: -
Josef Bacik authored
While looking for a performance regression a user was complaining about, I noticed that we had a regression with the varmail test of filebench. This was introduced by 0d10ee2e which keeps us from calling writepages in writepage. This is a correct change, however it happens to help the varmail test because we write out in larger chunks. This is largly to do with how we write out dirty pages for each transaction. If you run filebench with load varmail set $dir=/mnt/btrfs-test run 60 prior to this patch you would get ~1420 ops/second, but with the patch you get ~1200 ops/second. This is a 16% decrease. So since we know the range of dirty pages we want to write out, don't write out in one page chunks, write out in ranges. So to do this we call filemap_fdatawrite_range() on the range of bytes. Then we convert the DIRTY extents to NEED_WAIT extents. When we then call btrfs_wait_marked_extents() we only have to filemap_fdatawait_range() on that range and clear the NEED_WAIT extents. This doesn't get us back to our original speeds, but I've been seeing ~1380 ops/second, which is a <5% regression as opposed to a >15% regression. That is acceptable given that the original commit greatly reduces our latency to begin with. Thanks, Signed-off-by:
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Josef Bacik authored
If I have a range where I know a certain bit is and I want to set it to another bit the only option I have is to call set and then clear bit, which will result in 2 tree searches. This is inefficient, so introduce convert_extent_bit which will go through and set the bit I want and clear the old bit I don't want. Thanks, Signed-off-by: -
Josef Bacik authored
There is a bug that may lead to early ENOSPC in our reservation code. We've been checking against num_bytes which may be above and beyond what we want to actually reserve, which could give us a false ENOSPC. Fix this by making sure the unused space is above how much we want to reserve and not how much we're trying to flush. Thanks, Signed-off-by: -
Josef Bacik authored
In fixing how we deal with bad inodes, we had a regression in the orphan cleanup code, since it expects to get a bad inode back. So fix it to deal with getting -ESTALE back by deleting the orphan item manually and moving on. Thanks, Reported-by:
Simon Kirby <sim@hostway.ca> Signed-off-by:
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Josef Bacik authored
Johannes pointed out we were allocating only kernel pages for doing writes, which is kind of a big deal if you are on 32bit and have more than a gig of ram. So fix our allocations to use the mapping's gfp but still clear __GFP_FS so we don't re-enter. Thanks, Reported-by:
Johannes Weiner <jweiner@redhat.com> Signed-off-by:
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Josef Bacik authored
I kept getting warnings from evict because we were calling btrfs_start_transaction() with a transaction already started when doing a balance. This is because we remove a block group which requires a transaction, and the put the last reference on the cache inode. Instead of doing this we need to delay the iput so it is done not within a transaction having started. This gets rid of our warnings. Thanks, Signed-off-by: -
Josef Bacik authored
Checksums are charged in 2 different ways. The first case is when we're writing to the disk, we account for the new checksums with the delalloc block rsv. In order for this to work we check if we're allocating a block for the csum root and if trans->block_rsv == the delalloc block rsv. But when we're deleting the csums because of cow, this is charged to the global block rsv, and is done when we run the delayed refs. So we need to make sure that trans->block_rsv == NULL when running the delayed refs. So set it to NULL and reset it in should_end_transaction, and set it to NULL in commit_transaction. This got rid of the ridiculous amount of warnings I was seeing when trying to do a balance. Thanks, Signed-off-by: -
Josef Bacik authored
The only thing that we need to have a trans handle for is in reserve_metadata_bytes and thats to know how much flushing we can do. So instead of passing it around, just check current->journal_info for a trans_handle so we know if we can commit a transaction to try and free up space or not. Thanks, Signed-off-by: -
Josef Bacik authored
Since the durable block rsv stuff has been killed there is no need to get the block_rsv in btrfs_free_tree_block anymore. Signed-off-by: -
Josef Bacik authored
The alloc warnings everybody has been seeing is because we have been reserving space for csums, but we weren't actually using that space. So make get_block_rsv() return the trans->block_rsv if we're modifying the csum root. Also set the trans->block_rsv to NULL so that if we modify the csum root when running delayed ref's that comes out of the global reserve like it's supposed to. With this patch I'm not seeing those alloc warnings anymore. Thanks, Signed-off-by: -
Josef Bacik authored
Since free space inodes now use normal checksumming we need to make sure to account for their metadata use. So reserve metadata space, and then if we fail to write out the metadata we can just release it, otherwise it will be freed up when the io completes. Thanks, Signed-off-by: -
Josef Bacik authored
In moving some enospc stuff around I noticed that when we unmount we are often evicting the free space cache inodes before we do our last commit. This isn't bad, but it makes us constantly have to re-read the inodes back. So instead don't evict the cache until after we do our last commit, this will make things a little less crappy and makes a future enospc change work properly. Thanks, Signed-off-by: -
Josef Bacik authored
While debugging a different issue I noticed that we were always reserving space when we tried to use our truncate block rsv's. This is because they didn't have a ->size value, so use_block_rsv just assumes there is nothing reserved and it does a reserve_metadata_bytes. This is because btrfs_check_block_rsv() doesn't actually add to the size of the block rsv. That seems to be the right thing to do so set ->size to the minimum truncate size we need, since we will always only refill to that size anyway, and this way everything works out correctly. Signed-off-by: -
Josef Bacik authored
If we have to emergency reserve space we need to not increase the block_rsv size, otherwise we'll leak space. Take for instance delalloc, say we reserve 4k, and we use that 4k, and then we have to emergency allocate another 4k, we bump the size up to 8k, however we've only accounted for 4k in reservations in all of our supporting logic, so we'll go to free the 4k and end up having a size of 4k, which will cause us to later not free as much space. I saw this doing testing where I wasn't reserving enough space for something but was still leaking space, very frustrating. Thanks, Signed-off-by: -
Josef Bacik authored
When changing back to using a spin_lock to protect the extent counters I decided that since we would only be dropping our original extent, it was ok to just drop the extent and return. However since somebody else could have come in and done a reservation, we need to do the normal song and dance to clear the reservation out properly. So calculate how much space we need to free, and then subtract what we just attempted to reserve. If it's more then we know we need to drop those bytes from the delalloc block rsv. Thanks, Signed-off-by: -
Josef Bacik authored
We are setting ins_len to 1 even tho we are just modifying an item that should be there already. This may cause the search stuff to split nodes on the way down needelessly. Set this to 0 since we aren't inserting anything. Thanks, Signed-off-by: -
Josef Bacik authored
If you run xfstest 224 it you will get lots of messages about not being able to delete inodes and that they will be cleaned up next mount. This is because btrfs_block_rsv_check was not calling reserve_metadata_bytes with the ability to flush, so if there was not enough space, it simply failed. But in truncate and evict case we could easily flush space to try and get enough space to do our work, so make btrfs_block_rsv_check take a flush argument to pass down to reserve_metadata_bytes. Now xfstests 224 runs fine without all those complaints. Thanks, Signed-off-by: -
Josef Bacik authored
With btrfs_truncate_inode_items we always return if we have to go to another leaf, which makes us do our reservation again. This means we will only ever modify one leaf at a time, so we only need 1 items worth of slack space. Also, since we are deleting we will not be creating nodes as we go down, if anything we'll be free'ing them as we merge them together, so make a different calculation for truncate which will only have the worst case useage of COW'ing the entire path down to the leaf. Thanks, Signed-off-by: -
Josef Bacik authored
Lukas found a problem where if he tries to fallocate over the same region twice and the first fallocate took up all the space we would fail with ENOSPC. This is because we reserve the total space we want to use for fallocate, regardless of wether or not we will have to actually preallocate. So instead move the check into the loop where we actually have to do the preallocate. Thanks, Tested-by:
Lukas Czerner <lczerner@redhat.com> Signed-off-by:
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Josef Bacik authored
Since we've optimized the truncate path, we no longer require this function. Signed-off-by: -
Josef Bacik authored
Currently we're starting and stopping a transaction for no real reason, so kill that and just reserve enough space as if we can truncate all in one transaction. Also use btrfs_block_rsv_check() for our reserve to minimize the amount of space we may have to allocate for our slack space. Thanks, Signed-off-by: -
Josef Bacik authored
We will try and reserve metadata bytes in btrfs_block_rsv_check and if we cannot because we have a transaction open it will return EAGAIN, so we do not need to try and commit the transaction again. Signed-off-by:
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