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| author | Darrick J. Wong <djwong@kernel.org> | 2022-08-19 11:14:27 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-25 11:40:47 +0200 |
| commit | 90f414686bc48d8e7b886d059c94d2977d3601bd (patch) | |
| tree | 79a7f1e8c04577abad55e224147728cdbf1e9fe5 | |
| parent | 07e17dcd03e0b4267d3c71796cd18796b97bed4e (diff) | |
| download | linux-stable-90f414686bc48d8e7b886d059c94d2977d3601bd.tar.gz linux-stable-90f414686bc48d8e7b886d059c94d2977d3601bd.tar.bz2 linux-stable-90f414686bc48d8e7b886d059c94d2977d3601bd.zip | |
xfs: always succeed at setting the reserve pool size
[ Upstream commit 0baa2657dc4d79202148be79a3dc36c35f425060 ]
Nowadays, xfs_mod_fdblocks will always choose to fill the reserve pool
with freed blocks before adding to fdblocks. Therefore, we can change
the behavior of xfs_reserve_blocks slightly -- setting the target size
of the pool should always succeed, since a deficiency will eventually
be made up as blocks get freed.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Leah Rumancik <leah.rumancik@gmail.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/xfs/xfs_fsops.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c index 3c6d9d6836ef..5c2bea1e12a8 100644 --- a/fs/xfs/xfs_fsops.c +++ b/fs/xfs/xfs_fsops.c @@ -434,11 +434,14 @@ xfs_reserve_blocks( * The code below estimates how many blocks it can request from * fdblocks to stash in the reserve pool. This is a classic TOCTOU * race since fdblocks updates are not always coordinated via - * m_sb_lock. + * m_sb_lock. Set the reserve size even if there's not enough free + * space to fill it because mod_fdblocks will refill an undersized + * reserve when it can. */ free = percpu_counter_sum(&mp->m_fdblocks) - xfs_fdblocks_unavailable(mp); delta = request - mp->m_resblks; + mp->m_resblks = request; if (delta > 0 && free > 0) { /* * We'll either succeed in getting space from the free block @@ -455,10 +458,8 @@ xfs_reserve_blocks( * Update the reserve counters if blocks have been successfully * allocated. */ - if (!error) { - mp->m_resblks += fdblks_delta; + if (!error) mp->m_resblks_avail += fdblks_delta; - } } out: if (outval) { |