hw/9pfs: Use read-write lock for protecting fid path.
On rename we take the write lock and this ensure path
doesn't change as we operate on them.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index dc3e32b..356bb3b 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -1582,7 +1582,6 @@
gid_t gid;
ssize_t err = 0;
ssize_t offset = 7;
- V9fsString fullname;
V9fsString name;
V9fsFidState *fidp;
struct stat stbuf;
@@ -1590,7 +1589,6 @@
int32_t iounit;
V9fsPDU *pdu = opaque;
- v9fs_string_init(&fullname);
pdu_unmarshal(pdu, offset, "dsddd", &dfid, &name, &flags,
&mode, &gid);
@@ -1599,12 +1597,12 @@
err = -ENOENT;
goto out_nofid;
}
- v9fs_string_sprintf(&fullname, "%s/%s", fidp->path.data, name.data);
/* Ignore direct disk access hint until the server supports it. */
flags &= ~O_DIRECT;
- err = v9fs_co_open2(pdu->s, fidp, fullname.data, gid, flags, mode);
+ err = v9fs_co_open2(pdu->s, fidp, &name, gid,
+ flags | O_CREAT, mode, &stbuf);
if (err < 0) {
goto out;
}
@@ -1617,17 +1615,7 @@
*/
fidp->flags |= FID_NON_RECLAIMABLE;
}
- iounit = get_iounit(pdu->s, &fullname);
-
- err = v9fs_co_lstat(pdu->s, &fullname, &stbuf);
- if (err < 0) {
- fidp->fid_type = P9_FID_NONE;
- if (fidp->fs.fd > 0) {
- v9fs_co_close(pdu->s, fidp->fs.fd);
- }
- goto out;
- }
- v9fs_string_copy(&fidp->path, &fullname);
+ iounit = get_iounit(pdu->s, &fidp->path);
stat_to_qid(&stbuf, &qid);
offset += pdu_marshal(pdu, offset, "Qd", &qid, iounit);
err = offset;
@@ -1636,7 +1624,6 @@
out_nofid:
complete_pdu(pdu->s, pdu, err);
v9fs_string_free(&name);
- v9fs_string_free(&fullname);
}
static void v9fs_fsync(void *opaque)
@@ -2102,11 +2089,12 @@
goto out;
}
if (perm & P9_STAT_MODE_DIR) {
- err = v9fs_co_mkdir(pdu->s, fullname.data, perm & 0777,
- fidp->uid, -1);
+ err = v9fs_co_mkdir(pdu->s, fidp, &name, perm & 0777,
+ fidp->uid, -1, &stbuf);
if (err < 0) {
goto out;
}
+ v9fs_string_sprintf(&fullname, "%s/%s", fidp->path.data, name.data);
v9fs_string_copy(&fidp->path, &fullname);
err = v9fs_co_opendir(pdu->s, fidp);
if (err < 0) {
@@ -2114,11 +2102,13 @@
}
fidp->fid_type = P9_FID_DIR;
} else if (perm & P9_STAT_MODE_SYMLINK) {
- err = v9fs_co_symlink(pdu->s, fidp, extension.data,
- fullname.data, -1);
+ err = v9fs_co_symlink(pdu->s, fidp, &name,
+ extension.data, -1 , &stbuf);
if (err < 0) {
goto out;
}
+ v9fs_string_sprintf(&fullname, "%s/%s", fidp->path.data, name.data);
+ v9fs_string_copy(&fidp->path, &fullname);
} else if (perm & P9_STAT_MODE_LINK) {
int32_t nfid = atoi(extension.data);
V9fsFidState *nfidp = get_fid(pdu->s, nfid);
@@ -2126,12 +2116,19 @@
err = -EINVAL;
goto out;
}
+ v9fs_string_sprintf(&fullname, "%s/%s", fidp->path.data, name.data);
err = v9fs_co_link(pdu->s, &nfidp->path, &fullname);
+ put_fid(pdu->s, nfidp);
if (err < 0) {
- put_fid(pdu->s, nfidp);
goto out;
}
- put_fid(pdu->s, nfidp);
+ v9fs_string_sprintf(&fullname, "%s/%s", fidp->path.data, name.data);
+ v9fs_string_copy(&fidp->path, &fullname);
+ err = v9fs_co_lstat(pdu->s, &fidp->path, &stbuf);
+ if (err < 0) {
+ fidp->fid_type = P9_FID_NONE;
+ goto out;
+ }
} else if (perm & P9_STAT_MODE_DEVICE) {
char ctype;
uint32_t major, minor;
@@ -2155,26 +2152,32 @@
}
nmode |= perm & 0777;
- err = v9fs_co_mknod(pdu->s, &fullname, fidp->uid, -1,
- makedev(major, minor), nmode);
+ err = v9fs_co_mknod(pdu->s, fidp, &name, fidp->uid, -1,
+ makedev(major, minor), nmode, &stbuf);
if (err < 0) {
goto out;
}
+ v9fs_string_sprintf(&fullname, "%s/%s", fidp->path.data, name.data);
+ v9fs_string_copy(&fidp->path, &fullname);
} else if (perm & P9_STAT_MODE_NAMED_PIPE) {
- err = v9fs_co_mknod(pdu->s, &fullname, fidp->uid, -1,
- 0, S_IFIFO | (perm & 0777));
+ err = v9fs_co_mknod(pdu->s, fidp, &name, fidp->uid, -1,
+ 0, S_IFIFO | (perm & 0777), &stbuf);
if (err < 0) {
goto out;
}
+ v9fs_string_sprintf(&fullname, "%s/%s", fidp->path.data, name.data);
+ v9fs_string_copy(&fidp->path, &fullname);
} else if (perm & P9_STAT_MODE_SOCKET) {
- err = v9fs_co_mknod(pdu->s, &fullname, fidp->uid, -1,
- 0, S_IFSOCK | (perm & 0777));
+ err = v9fs_co_mknod(pdu->s, fidp, &name, fidp->uid, -1,
+ 0, S_IFSOCK | (perm & 0777), &stbuf);
if (err < 0) {
goto out;
}
+ v9fs_string_sprintf(&fullname, "%s/%s", fidp->path.data, name.data);
+ v9fs_string_copy(&fidp->path, &fullname);
} else {
- err = v9fs_co_open2(pdu->s, fidp, fullname.data, -1,
- omode_to_uflags(mode)|O_CREAT, perm);
+ err = v9fs_co_open2(pdu->s, fidp, &name, -1,
+ omode_to_uflags(mode)|O_CREAT, perm, &stbuf);
if (err < 0) {
goto out;
}
@@ -2188,16 +2191,7 @@
fidp->flags |= FID_NON_RECLAIMABLE;
}
}
- err = v9fs_co_lstat(pdu->s, &fullname, &stbuf);
- if (err < 0) {
- fidp->fid_type = P9_FID_NONE;
- if (fidp->fs.fd) {
- v9fs_co_close(pdu->s, fidp->fs.fd);
- }
- goto out;
- }
iounit = get_iounit(pdu->s, &fidp->path);
- v9fs_string_copy(&fidp->path, &fullname);
stat_to_qid(&stbuf, &qid);
offset += pdu_marshal(pdu, offset, "Qd", &qid, iounit);
err = offset;
@@ -2215,7 +2209,6 @@
V9fsPDU *pdu = opaque;
V9fsString name;
V9fsString symname;
- V9fsString fullname;
V9fsFidState *dfidp;
V9fsQID qid;
struct stat stbuf;
@@ -2224,7 +2217,6 @@
gid_t gid;
size_t offset = 7;
- v9fs_string_init(&fullname);
pdu_unmarshal(pdu, offset, "dssd", &dfid, &name, &symname, &gid);
dfidp = get_fid(pdu->s, dfid);
@@ -2232,13 +2224,7 @@
err = -EINVAL;
goto out_nofid;
}
-
- v9fs_string_sprintf(&fullname, "%s/%s", dfidp->path.data, name.data);
- err = v9fs_co_symlink(pdu->s, dfidp, symname.data, fullname.data, gid);
- if (err < 0) {
- goto out;
- }
- err = v9fs_co_lstat(pdu->s, &fullname, &stbuf);
+ err = v9fs_co_symlink(pdu->s, dfidp, &name, symname.data, gid, &stbuf);
if (err < 0) {
goto out;
}
@@ -2251,7 +2237,6 @@
complete_pdu(pdu->s, pdu, err);
v9fs_string_free(&name);
v9fs_string_free(&symname);
- v9fs_string_free(&fullname);
}
static void v9fs_flush(void *opaque)
@@ -2469,7 +2454,9 @@
}
BUG_ON(fidp->fid_type != P9_FID_NONE);
+ qemu_co_rwlock_wrlock(&s->rename_lock);
err = v9fs_complete_rename(s, fidp, newdirfid, &name);
+ qemu_co_rwlock_unlock(&s->rename_lock);
if (!err) {
err = offset;
}
@@ -2551,7 +2538,9 @@
pdu_unmarshal(pdu, offset, "dsds", &olddirfid,
&old_name, &newdirfid, &new_name);
+ qemu_co_rwlock_wrlock(&s->rename_lock);
err = v9fs_complete_renameat(s, olddirfid, &old_name, newdirfid, &new_name);
+ qemu_co_rwlock_unlock(&s->rename_lock);
if (!err) {
err = offset;
}
@@ -2735,12 +2724,10 @@
size_t offset = 7;
V9fsString name;
struct stat stbuf;
- V9fsString fullname;
V9fsFidState *fidp;
V9fsPDU *pdu = opaque;
V9fsState *s = pdu->s;
- v9fs_string_init(&fullname);
pdu_unmarshal(pdu, offset, "dsdddd", &fid, &name, &mode,
&major, &minor, &gid);
@@ -2749,13 +2736,8 @@
err = -ENOENT;
goto out_nofid;
}
- v9fs_string_sprintf(&fullname, "%s/%s", fidp->path.data, name.data);
- err = v9fs_co_mknod(s, &fullname, fidp->uid, gid,
- makedev(major, minor), mode);
- if (err < 0) {
- goto out;
- }
- err = v9fs_co_lstat(s, &fullname, &stbuf);
+ err = v9fs_co_mknod(s, fidp, &name, fidp->uid, gid,
+ makedev(major, minor), mode, &stbuf);
if (err < 0) {
goto out;
}
@@ -2766,7 +2748,6 @@
put_fid(s, fidp);
out_nofid:
complete_pdu(s, pdu, err);
- v9fs_string_free(&fullname);
v9fs_string_free(&name);
}
@@ -2867,14 +2848,13 @@
size_t offset = 7;
int32_t fid;
struct stat stbuf;
- V9fsString name, fullname;
V9fsQID qid;
+ V9fsString name;
V9fsFidState *fidp;
gid_t gid;
int mode;
int err = 0;
- v9fs_string_init(&fullname);
pdu_unmarshal(pdu, offset, "dsdd", &fid, &name, &mode, &gid);
fidp = get_fid(pdu->s, fid);
@@ -2882,12 +2862,7 @@
err = -ENOENT;
goto out_nofid;
}
- v9fs_string_sprintf(&fullname, "%s/%s", fidp->path.data, name.data);
- err = v9fs_co_mkdir(pdu->s, fullname.data, mode, fidp->uid, gid);
- if (err < 0) {
- goto out;
- }
- err = v9fs_co_lstat(pdu->s, &fullname, &stbuf);
+ err = v9fs_co_mkdir(pdu->s, fidp, &name, mode, fidp->uid, gid, &stbuf);
if (err < 0) {
goto out;
}
@@ -2898,7 +2873,6 @@
put_fid(pdu->s, fidp);
out_nofid:
complete_pdu(pdu->s, pdu, err);
- v9fs_string_free(&fullname);
v9fs_string_free(&name);
}
