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authorSage Weil <sage@inktank.com>2012-07-31 22:27:36 +0400
committerSage Weil <sage@inktank.com>2012-08-02 20:11:19 +0400
commit5ef50c3bec20060bc114f62d6503c5d86d70bdd7 (patch)
tree0777f7c9bef358fe7778e11874a6a750e0d2ceab /fs
parent1a9b4993b70fb1884716902774dc9025b457760d (diff)
downloadlinux-5ef50c3bec20060bc114f62d6503c5d86d70bdd7.tar.xz
ceph: simplify+fix atomic_open
The initial ->atomic_open op was carried over from the old intent code, which was incomplete and didn't really work. Replace it with a fresh method. In particular: * always attempt to do an atomic open+lookup, both for the create case and for lookups of existing files. * fix symlink handling by returning 1 to the VFS so that we can follow the link to its destination. This fixes a longstanding ceph bug (#2392). Signed-off-by: Sage Weil <sage@inktank.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/ceph/dir.c38
-rw-r--r--fs/ceph/file.c62
-rw-r--r--fs/ceph/super.h6
3 files changed, 40 insertions, 66 deletions
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index f391f1e75414..e5b77319c97b 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -633,44 +633,6 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
return dentry;
}
-int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
- struct file *file, unsigned flags, umode_t mode,
- int *opened)
-{
- int err;
- struct dentry *res = NULL;
-
- if (!(flags & O_CREAT)) {
- if (dentry->d_name.len > NAME_MAX)
- return -ENAMETOOLONG;
-
- err = ceph_init_dentry(dentry);
- if (err < 0)
- return err;
-
- return ceph_lookup_open(dir, dentry, file, flags, mode, opened);
- }
-
- if (d_unhashed(dentry)) {
- res = ceph_lookup(dir, dentry, 0);
- if (IS_ERR(res))
- return PTR_ERR(res);
-
- if (res)
- dentry = res;
- }
-
- /* We don't deal with positive dentries here */
- if (dentry->d_inode)
- return finish_no_open(file, res);
-
- *opened |= FILE_CREATED;
- err = ceph_lookup_open(dir, dentry, file, flags, mode, opened);
- dput(res);
-
- return err;
-}
-
/*
* If we do a create but get no trace back from the MDS, follow up with
* a lookup (the VFS expects us to link up the provided dentry).
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 1b81d6c31878..ecebbc09bfc7 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -4,6 +4,7 @@
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/file.h>
+#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/writeback.h>
@@ -106,9 +107,6 @@ static int ceph_init_file(struct inode *inode, struct file *file, int fmode)
}
/*
- * If the filp already has private_data, that means the file was
- * already opened by intent during lookup, and we do nothing.
- *
* If we already have the requisite capabilities, we can satisfy
* the open request locally (no need to request new caps from the
* MDS). We do, however, need to inform the MDS (asynchronously)
@@ -207,24 +205,29 @@ out:
/*
- * Do a lookup + open with a single request.
- *
- * If this succeeds, but some subsequent check in the vfs
- * may_open() fails, the struct *file gets cleaned up (i.e.
- * ceph_release gets called). So fear not!
+ * Do a lookup + open with a single request. If we get a non-existent
+ * file or symlink, return 1 so the VFS can retry.
*/
-int ceph_lookup_open(struct inode *dir, struct dentry *dentry,
+int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
struct file *file, unsigned flags, umode_t mode,
int *opened)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_mds_request *req;
- struct dentry *ret;
+ struct dentry *dn;
int err;
- dout("ceph_lookup_open dentry %p '%.*s' flags %d mode 0%o\n",
- dentry, dentry->d_name.len, dentry->d_name.name, flags, mode);
+ dout("atomic_open %p dentry %p '%.*s' %s flags %d mode 0%o\n",
+ dir, dentry, dentry->d_name.len, dentry->d_name.name,
+ d_unhashed(dentry) ? "unhashed" : "hashed", flags, mode);
+
+ if (dentry->d_name.len > NAME_MAX)
+ return -ENAMETOOLONG;
+
+ err = ceph_init_dentry(dentry);
+ if (err < 0)
+ return err;
/* do the open */
req = prepare_open_request(dir->i_sb, flags, mode);
@@ -241,22 +244,31 @@ int ceph_lookup_open(struct inode *dir, struct dentry *dentry,
(flags & (O_CREAT|O_TRUNC)) ? dir : NULL,
req);
err = ceph_handle_snapdir(req, dentry, err);
- if (err)
- goto out;
- if ((flags & O_CREAT) && !req->r_reply_info.head->is_dentry)
+ if (err == 0 && (flags & O_CREAT) && !req->r_reply_info.head->is_dentry)
err = ceph_handle_notrace_create(dir, dentry);
- if (err)
- goto out;
- err = finish_open(file, req->r_dentry, ceph_open, opened);
-out:
- ret = ceph_finish_lookup(req, dentry, err);
- ceph_mdsc_put_request(req);
- dout("ceph_lookup_open result=%p\n", ret);
- if (IS_ERR(ret))
- return PTR_ERR(ret);
+ if (d_unhashed(dentry)) {
+ dn = ceph_finish_lookup(req, dentry, err);
+ if (IS_ERR(dn))
+ err = PTR_ERR(dn);
+ } else {
+ /* we were given a hashed negative dentry */
+ dn = NULL;
+ }
+ if (err)
+ goto out_err;
+ if (dn || dentry->d_inode == NULL || S_ISLNK(dentry->d_inode->i_mode)) {
+ /* make vfs retry on splice, ENOENT, or symlink */
+ dout("atomic_open finish_no_open on dn %p\n", dn);
+ err = finish_no_open(file, dn);
+ } else {
+ dout("atomic_open finish_open on dn %p\n", dn);
+ err = finish_open(file, dentry, ceph_open, opened);
+ }
- dput(ret);
+out_err:
+ ceph_mdsc_put_request(req);
+ dout("atomic_open result=%d\n", err);
return err;
}
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index ebc95cc652be..66ebe720e40d 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -806,9 +806,9 @@ extern int ceph_copy_from_page_vector(struct page **pages,
loff_t off, size_t len);
extern struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags);
extern int ceph_open(struct inode *inode, struct file *file);
-extern int ceph_lookup_open(struct inode *dir, struct dentry *dentry,
- struct file *od, unsigned flags,
- umode_t mode, int *opened);
+extern int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
+ struct file *file, unsigned flags, umode_t mode,
+ int *opened);
extern int ceph_release(struct inode *inode, struct file *filp);
/* dir.c */