diff options
author | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2023-06-09 22:26:25 +0300 |
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committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2023-08-23 22:58:47 +0300 |
commit | 303a78052091c81e9003915c521fdca1c7e117af (patch) | |
tree | 2616e0e3ddc48fee94929cf7e1220013b0e2377f /fs/nfs/nfs4proc.c | |
parent | 8d18f6c5bb864d97a730f471c56cdecf313efe64 (diff) | |
download | linux-303a78052091c81e9003915c521fdca1c7e117af.tar.xz |
NFSv4.2: Rework scratch handling for READ_PLUS (again)
I found that the read code might send multiple requests using the same
nfs_pgio_header, but nfs4_proc_read_setup() is only called once. This is
how we ended up occasionally double-freeing the scratch buffer, but also
means we set a NULL pointer but non-zero length to the xdr scratch
buffer. This results in an oops the first time decoding needs to copy
something to scratch, which frequently happens when decoding READ_PLUS
hole segments.
I fix this by moving scratch handling into the pageio read code. I
provide a function to allocate scratch space for decoding read replies,
and free the scratch buffer when the nfs_pgio_header is freed.
Fixes: fbd2a05f29a9 (NFSv4.2: Rework scratch handling for READ_PLUS)
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'fs/nfs/nfs4proc.c')
-rw-r--r-- | fs/nfs/nfs4proc.c | 13 |
1 files changed, 1 insertions, 12 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 832fa226b8f2..3c24c3c99e8a 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -5438,18 +5438,8 @@ static bool nfs4_read_plus_not_supported(struct rpc_task *task, return false; } -static inline void nfs4_read_plus_scratch_free(struct nfs_pgio_header *hdr) -{ - if (hdr->res.scratch) { - kfree(hdr->res.scratch); - hdr->res.scratch = NULL; - } -} - static int nfs4_read_done(struct rpc_task *task, struct nfs_pgio_header *hdr) { - nfs4_read_plus_scratch_free(hdr); - if (!nfs4_sequence_done(task, &hdr->res.seq_res)) return -EAGAIN; if (nfs4_read_stateid_changed(task, &hdr->args)) @@ -5469,8 +5459,7 @@ static bool nfs42_read_plus_support(struct nfs_pgio_header *hdr, /* Note: We don't use READ_PLUS with pNFS yet */ if (nfs_server_capable(hdr->inode, NFS_CAP_READ_PLUS) && !hdr->ds_clp) { msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ_PLUS]; - hdr->res.scratch = kmalloc(32, GFP_KERNEL); - return hdr->res.scratch != NULL; + return nfs_read_alloc_scratch(hdr, READ_PLUS_SCRATCH_SIZE); } return false; } |