2005-06-01 22:51:09

by NeilBrown

[permalink] [raw]
Subject: [PATCH kNFSd 002 of 28] nfs4: hold filp while reading or writing


We're trying to read and write from a struct file that we may not hold a
reference to any more (since a close could be processed as soon as we drop the
state lock).

Signed-off-by: J. Bruce Fields <[email protected]>
Signed-off-by: Neil Brown <[email protected]>

### Diffstat output
./fs/nfsd/nfs4proc.c | 15 ++++++++++++---
1 files changed, 12 insertions(+), 3 deletions(-)

diff ./fs/nfsd/nfs4proc.c~current~ ./fs/nfsd/nfs4proc.c
--- ./fs/nfsd/nfs4proc.c~current~ 2005-05-31 14:20:58.000000000 +1000
+++ ./fs/nfsd/nfs4proc.c 2005-05-31 14:20:58.000000000 +1000
@@ -45,6 +45,7 @@
#include <linux/param.h>
#include <linux/major.h>
#include <linux/slab.h>
+#include <linux/file.h>

#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
@@ -477,26 +478,27 @@ static inline int
nfsd4_read(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_read *read)
{
int status;
- struct file *filp = NULL;

/* no need to check permission - this will be done in nfsd_read() */

+ read->rd_filp = NULL;
if (read->rd_offset >= OFFSET_MAX)
return nfserr_inval;

nfs4_lock_state();
/* check stateid */
if ((status = nfs4_preprocess_stateid_op(current_fh, &read->rd_stateid,
- CHECK_FH | RD_STATE, &filp))) {
+ CHECK_FH | RD_STATE, &read->rd_filp))) {
dprintk("NFSD: nfsd4_read: couldn't process stateid!\n");
goto out;
}
+ if (read->rd_filp)
+ get_file(read->rd_filp);
status = nfs_ok;
out:
nfs4_unlock_state();
read->rd_rqstp = rqstp;
read->rd_fhp = current_fh;
- read->rd_filp = filp;
return status;
}

@@ -633,6 +635,8 @@ nfsd4_write(struct svc_rqst *rqstp, stru
dprintk("NFSD: nfsd4_write: couldn't process stateid!\n");
goto out;
}
+ if (filp)
+ get_file(filp);
nfs4_unlock_state();

write->wr_bytes_written = write->wr_buflen;
@@ -644,6 +648,8 @@ nfsd4_write(struct svc_rqst *rqstp, stru
status = nfsd_write(rqstp, current_fh, filp, write->wr_offset,
write->wr_vec, write->wr_vlen, write->wr_buflen,
&write->wr_how_written);
+ if (filp)
+ fput(filp);

if (status == nfserr_symlink)
status = nfserr_inval;
@@ -932,6 +938,9 @@ encode_op:
nfs4_put_stateowner(replay_owner);
replay_owner = NULL;
}
+ /* XXX Ugh, we need to get rid of this kind of special case: */
+ if (op->opnum == OP_READ && op->u.read.rd_filp)
+ fput(op->u.read.rd_filp);
}

out:


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