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authorLinus Torvalds <torvalds@linux-foundation.org>2022-06-22 08:09:49 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2022-06-22 08:09:49 -0500
commit3abc3ae553c7ed73365b385b9a4cffc5176aae45 (patch)
tree4cccb5183e9949f4b7e76d5d27af51806af76b2b /fs
parentca1fdab7fd27eb069df1384b2850dcd0c2bebe8d (diff)
parentb0017602fdf6bd3f344dd49eaee8b6ffeed6dbac (diff)
downloadlinux-3abc3ae553c7ed73365b385b9a4cffc5176aae45.tar.bz2
Merge tag '9p-for-5.19-rc4' of https://github.com/martinetd/linux
Pull 9pfs fixes from Dominique Martinet: "A couple of fid refcount and fscache fixes: - fid refcounting was incorrect in some corner cases and would leak resources, only freed at umount time. The first three commits fix three such cases - 'cache=loose' or fscache was broken when trying to write a partial page to a file with no read permission since the rework a few releases ago. The fix taken here is just to restore old behavior of using the special 'writeback_fid' for such reads, which is open as root/RDWR and such not get complains that we try to read on a WRONLY fid. Long-term it'd be nice to get rid of this and not issue the read at all (skip cache?) in such cases, but that direction hasn't progressed" * tag '9p-for-5.19-rc4' of https://github.com/martinetd/linux: 9p: fix EBADF errors in cached mode 9p: Fix refcounting during full path walks for fid lookups 9p: fix fid refcount leak in v9fs_vfs_get_link 9p: fix fid refcount leak in v9fs_vfs_atomic_open_dotl
Diffstat (limited to 'fs')
-rw-r--r--fs/9p/fid.c22
-rw-r--r--fs/9p/vfs_addr.c13
-rw-r--r--fs/9p/vfs_inode.c8
-rw-r--r--fs/9p/vfs_inode_dotl.c3
4 files changed, 29 insertions, 17 deletions
diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index 79df61fe0e59..baf2b152229e 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -152,7 +152,7 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry,
const unsigned char **wnames, *uname;
int i, n, l, clone, access;
struct v9fs_session_info *v9ses;
- struct p9_fid *fid, *old_fid = NULL;
+ struct p9_fid *fid, *old_fid;
v9ses = v9fs_dentry2v9ses(dentry);
access = v9ses->flags & V9FS_ACCESS_MASK;
@@ -194,13 +194,12 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry,
if (IS_ERR(fid))
return fid;
+ refcount_inc(&fid->count);
v9fs_fid_add(dentry->d_sb->s_root, fid);
}
/* If we are root ourself just return that */
- if (dentry->d_sb->s_root == dentry) {
- refcount_inc(&fid->count);
+ if (dentry->d_sb->s_root == dentry)
return fid;
- }
/*
* Do a multipath walk with attached root.
* When walking parent we need to make sure we
@@ -212,6 +211,7 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry,
fid = ERR_PTR(n);
goto err_out;
}
+ old_fid = fid;
clone = 1;
i = 0;
while (i < n) {
@@ -221,19 +221,15 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry,
* walk to ensure none of the patch component change
*/
fid = p9_client_walk(fid, l, &wnames[i], clone);
+ /* non-cloning walk will return the same fid */
+ if (fid != old_fid) {
+ p9_client_clunk(old_fid);
+ old_fid = fid;
+ }
if (IS_ERR(fid)) {
- if (old_fid) {
- /*
- * If we fail, clunk fid which are mapping
- * to path component and not the last component
- * of the path.
- */
- p9_client_clunk(old_fid);
- }
kfree(wnames);
goto err_out;
}
- old_fid = fid;
i += l;
clone = 0;
}
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index a8f512b44a85..d0833fa69faf 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -58,8 +58,21 @@ static void v9fs_issue_read(struct netfs_io_subrequest *subreq)
*/
static int v9fs_init_request(struct netfs_io_request *rreq, struct file *file)
{
+ struct inode *inode = file_inode(file);
+ struct v9fs_inode *v9inode = V9FS_I(inode);
struct p9_fid *fid = file->private_data;
+ BUG_ON(!fid);
+
+ /* we might need to read from a fid that was opened write-only
+ * for read-modify-write of page cache, use the writeback fid
+ * for that */
+ if (rreq->origin == NETFS_READ_FOR_WRITE &&
+ (fid->mode & O_ACCMODE) == O_WRONLY) {
+ fid = v9inode->writeback_fid;
+ BUG_ON(!fid);
+ }
+
refcount_inc(&fid->count);
rreq->netfs_priv = fid;
return 0;
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 419d2f3cf2c2..3d8297714772 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -1251,15 +1251,15 @@ static const char *v9fs_vfs_get_link(struct dentry *dentry,
return ERR_PTR(-ECHILD);
v9ses = v9fs_dentry2v9ses(dentry);
- fid = v9fs_fid_lookup(dentry);
+ if (!v9fs_proto_dotu(v9ses))
+ return ERR_PTR(-EBADF);
+
p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
+ fid = v9fs_fid_lookup(dentry);
if (IS_ERR(fid))
return ERR_CAST(fid);
- if (!v9fs_proto_dotu(v9ses))
- return ERR_PTR(-EBADF);
-
st = p9_client_stat(fid);
p9_client_clunk(fid);
if (IS_ERR(st))
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index d17502a738a9..b6eb1160296c 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -274,6 +274,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
if (IS_ERR(ofid)) {
err = PTR_ERR(ofid);
p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
+ p9_client_clunk(dfid);
goto out;
}
@@ -285,6 +286,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
if (err) {
p9_debug(P9_DEBUG_VFS, "Failed to get acl values in creat %d\n",
err);
+ p9_client_clunk(dfid);
goto error;
}
err = p9_client_create_dotl(ofid, name, v9fs_open_to_dotl_flags(flags),
@@ -292,6 +294,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
if (err < 0) {
p9_debug(P9_DEBUG_VFS, "p9_client_open_dotl failed in creat %d\n",
err);
+ p9_client_clunk(dfid);
goto error;
}
v9fs_invalidate_inode_attr(dir);