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NFSv4.x/pnfs: Fix a race between layoutget and pnfs_destroy_layout

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If the server reboots while there is a layoutget outstanding, then
the call to pnfs_choose_layoutget_stateid() will fail with an EAGAIN
error, which causes an infinite loop in send_layoutget(). The reason
why we never break out of the loop is that the layout 'plh_block_lgets'
field is never cleared.

Fix is to replace plh_block_lgets with NFS_LAYOUT_INVALID_STID, which
can be reset after a new layoutget.

Fixes: ab7d763e47 ("pNFS: Ensure nfs4_layoutget_prepare returns...")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Trond Myklebust 2016-02-22 17:34:59 -05:00
parent d07fbb8fdf
commit 2454dfea0a
1 changed files with 22 additions and 2 deletions
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24
fs/nfs/pnfs.c
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@ -252,6 +252,27 @@ pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
}
}
/*
* Mark a pnfs_layout_hdr and all associated layout segments as invalid
*
* In order to continue using the pnfs_layout_hdr, a full recovery
* is required.
* Note that caller must hold inode->i_lock.
*/
static void
pnfs_mark_layout_stateid_invalid(struct pnfs_layout_hdr *lo,
struct list_head *lseg_list)
{
struct pnfs_layout_range range = {
.iomode = IOMODE_ANY,
.offset = 0,
.length = NFS4_MAX_UINT64,
};
set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
pnfs_mark_matching_lsegs_invalid(lo, lseg_list, &range);
}
static int
pnfs_iomode_to_fail_bit(u32 iomode)
{
@ -554,9 +575,8 @@ pnfs_destroy_layout(struct nfs_inode *nfsi)
spin_lock(&nfsi->vfs_inode.i_lock);
lo = nfsi->layout;
if (lo) {
lo->plh_block_lgets++; /* permanently block new LAYOUTGETs */
pnfs_mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
pnfs_get_layout_hdr(lo);
pnfs_mark_layout_stateid_invalid(lo, &tmp_list);
pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
spin_unlock(&nfsi->vfs_inode.i_lock);