From: Brian Foster bfoster@redhat.com
mainline-inclusion from mainline-v5.12-rc4 commit 2675ad3890db93e58f2264d07c2d1f615ec5adf7 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4KIAO CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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perag reservation is enabled at mount time on a per AG basis. The upcoming change to set aside allocbt blocks from block reservation requires a populated allocbt counter as soon as possible after mount to be fully effective against large perag reservations. Therefore as a preparation step, initialize the pagf on all mounts where at least one reservation is active. Note that this already occurs to some degree on most default format filesystems as reservation requirement calculations already depend on the AGF or AGI, depending on the reservation type.
Signed-off-by: Brian Foster bfoster@redhat.com Reviewed-by: Chandan Babu R chandanrlinux@gmail.com Reviewed-by: Allison Henderson allison.henderson@oracle.com Reviewed-by: Darrick J. Wong djwong@kernel.org Signed-off-by: Darrick J. Wong djwong@kernel.org Signed-off-by: Guo Xuenan guoxuenan@huawei.com Reviewed-by: Lihong Kou koulihong@huawei.com Reviewed-by: Zhang Yi yi.zhang@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- fs/xfs/libxfs/xfs_ag_resv.c | 34 +++++++++++++++++++++++----------- 1 file changed, 23 insertions(+), 11 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_ag_resv.c b/fs/xfs/libxfs/xfs_ag_resv.c index fdfe6dc0d307..0edf1aea1a37 100644 --- a/fs/xfs/libxfs/xfs_ag_resv.c +++ b/fs/xfs/libxfs/xfs_ag_resv.c @@ -249,7 +249,8 @@ xfs_ag_resv_init( xfs_agnumber_t agno = pag->pag_agno; xfs_extlen_t ask; xfs_extlen_t used; - int error = 0; + int error = 0, error2; + bool has_resv = false;
/* Create the metadata reservation. */ if (pag->pag_meta_resv.ar_asked == 0) { @@ -287,6 +288,8 @@ xfs_ag_resv_init( if (error) goto out; } + if (ask) + has_resv = true; }
/* Create the RMAPBT metadata reservation */ @@ -300,19 +303,28 @@ xfs_ag_resv_init( error = __xfs_ag_resv_init(pag, XFS_AG_RESV_RMAPBT, ask, used); if (error) goto out; + if (ask) + has_resv = true; }
-#ifdef DEBUG - /* need to read in the AGF for the ASSERT below to work */ - error = xfs_alloc_pagf_init(pag->pag_mount, tp, pag->pag_agno, 0); - if (error) - return error; - - ASSERT(xfs_perag_resv(pag, XFS_AG_RESV_METADATA)->ar_reserved + - xfs_perag_resv(pag, XFS_AG_RESV_RMAPBT)->ar_reserved <= - pag->pagf_freeblks + pag->pagf_flcount); -#endif out: + /* + * Initialize the pagf if we have at least one active reservation on the + * AG. This may have occurred already via reservation calculation, but + * fall back to an explicit init to ensure the in-core allocbt usage + * counters are initialized as soon as possible. This is important + * because filesystems with large perag reservations are susceptible to + * free space reservation problems that the allocbt counter is used to + * address. + */ + if (has_resv) { + error2 = xfs_alloc_pagf_init(mp, tp, pag->pag_agno, 0); + if (error2) + return error2; + ASSERT(xfs_perag_resv(pag, XFS_AG_RESV_METADATA)->ar_reserved + + xfs_perag_resv(pag, XFS_AG_RESV_RMAPBT)->ar_reserved <= + pag->pagf_freeblks + pag->pagf_flcount); + } return error; }