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| author |   Trond Myklebust <trond.myklebust@hammerspace.com> | 2020-04-13 15:55:21 -0400 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@hammerspace.com> | 2020-04-13 15:55:21 -0400 |
| commit | fbf4bcc9a8373122881909331f2f9566a128126e (patch) | |
| tree | 8ab1e8a6c18cc76d2e520dc6095cbead15847f81 /fs/nfs | |
| parent | Linux 5.7-rc1 (diff) | |
| download | wireguard-linux-fbf4bcc9a8373122881909331f2f9566a128126e.tar.xz wireguard-linux-fbf4bcc9a8373122881909331f2f9566a128126e.zip | |
NFS: Fix an ABBA spinlock issue in pnfs_update_layout()
We need to drop the inode spinlock while calling nfs4_select_rw_stateid(),
since nfs4_copy_delegation_stateid() could take the delegation lock.
Note that it is safe to do this, since all other calls to
pnfs_update_layout() for that inode will find themselves blocked by
the lock we hold on NFS_LAYOUT_FIRST_LAYOUTGET.
Fixes: fc51b1cf391d ("NFS: Beware when dereferencing the delegation cred")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Diffstat (limited to 'fs/nfs')
| -rw-r--r-- | fs/nfs/pnfs.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index f2dc35c22964..b8d78f393365 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -2023,6 +2023,7 @@ lookup_again: goto lookup_again; } + spin_unlock(&ino->i_lock); first = true; status = nfs4_select_rw_stateid(ctx->state, iomode == IOMODE_RW ? FMODE_WRITE : FMODE_READ, @@ -2032,12 +2033,12 @@ lookup_again: trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg, PNFS_UPDATE_LAYOUT_INVALID_OPEN); - spin_unlock(&ino->i_lock); nfs4_schedule_stateid_recovery(server, ctx->state); pnfs_clear_first_layoutget(lo); pnfs_put_layout_hdr(lo); goto lookup_again; } + spin_lock(&ino->i_lock); } else { nfs4_stateid_copy(&stateid, &lo->plh_stateid); } |