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author | Dave Chinner <dchinner@redhat.com> | 2021-06-18 08:21:52 -0700 |
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committer | Darrick J. Wong <djwong@kernel.org> | 2021-06-21 10:12:33 -0700 |
commit | 5f9b4b0de8dc2fb8eb655463b438001c111570fe (patch) | |
tree | 6885ac605fb4c2ab1b7eb9f188d282e687288d2e /fs/xfs/xfs_log.h | |
parent | 19f4e7cc819771812a7f527d7897c2deffbf7a00 (diff) | |
download | linux-5f9b4b0de8dc2fb8eb655463b438001c111570fe.tar.gz |
xfs: xfs_log_force_lsn isn't passed a LSN
In doing an investigation into AIL push stalls, I was looking at the log force code to see if an async CIL push could be done instead. This lead me to xfs_log_force_lsn() and looking at how it works. xfs_log_force_lsn() is only called from inode synchronisation contexts such as fsync(), and it takes the ip->i_itemp->ili_last_lsn value as the LSN to sync the log to. This gets passed to xlog_cil_force_lsn() via xfs_log_force_lsn() to flush the CIL to the journal, and then used by xfs_log_force_lsn() to flush the iclogs to the journal. The problem is that ip->i_itemp->ili_last_lsn does not store a log sequence number. What it stores is passed to it from the ->iop_committing method, which is called by xfs_log_commit_cil(). The value this passes to the iop_committing method is the CIL context sequence number that the item was committed to. As it turns out, xlog_cil_force_lsn() converts the sequence to an actual commit LSN for the related context and returns that to xfs_log_force_lsn(). xfs_log_force_lsn() overwrites it's "lsn" variable that contained a sequence with an actual LSN and then uses that to sync the iclogs. This caused me some confusion for a while, even though I originally wrote all this code a decade ago. ->iop_committing is only used by a couple of log item types, and only inode items use the sequence number it is passed. Let's clean up the API, CIL structures and inode log item to call it a sequence number, and make it clear that the high level code is using CIL sequence numbers and not on-disk LSNs for integrity synchronisation purposes. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Diffstat (limited to 'fs/xfs/xfs_log.h')
-rw-r--r-- | fs/xfs/xfs_log.h | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h index 99f9d6ed9598..813b972e9788 100644 --- a/fs/xfs/xfs_log.h +++ b/fs/xfs/xfs_log.h @@ -106,7 +106,7 @@ struct xfs_item_ops; struct xfs_trans; int xfs_log_force(struct xfs_mount *mp, uint flags); -int xfs_log_force_lsn(struct xfs_mount *mp, xfs_lsn_t lsn, uint flags, +int xfs_log_force_seq(struct xfs_mount *mp, xfs_csn_t seq, uint flags, int *log_forced); int xfs_log_mount(struct xfs_mount *mp, struct xfs_buftarg *log_target, @@ -131,8 +131,6 @@ bool xfs_log_writable(struct xfs_mount *mp); struct xlog_ticket *xfs_log_ticket_get(struct xlog_ticket *ticket); void xfs_log_ticket_put(struct xlog_ticket *ticket); -void xfs_log_commit_cil(struct xfs_mount *mp, struct xfs_trans *tp, - xfs_lsn_t *commit_lsn, bool regrant); void xlog_cil_process_committed(struct list_head *list); bool xfs_log_item_in_current_chkpt(struct xfs_log_item *lip); |