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| author | Steven Danneman <steven.danneman@isilon.com> | 2009-05-14 23:12:23 +0000 |
|---|---|---|
| committer | Tim Prouty <tprouty@samba.org> | 2009-09-24 11:31:21 -0700 |
| commit | 74c0a7a1d34a75abec32cc46ab0b02b483160215 (patch) | |
| tree | b2a28dd2d7c7ad6db3ad7492da1bd25cf2072d05 | |
| parent | 5e9aade51657a22dba2c65ffc1aab1be7c532e61 (diff) | |
| download | samba-74c0a7a1d34a75abec32cc46ab0b02b483160215.tar.gz samba-74c0a7a1d34a75abec32cc46ab0b02b483160215.tar.bz2 samba-74c0a7a1d34a75abec32cc46ab0b02b483160215.zip | |
s3 onefs: Fix a race condition exists in onefs_open.c between multiple opens to the same file.
Two openers can stat a file at the same time, see that it doesn't exist,
and then both race to open it first. The loser will enter
onefs_open_file_ntcreate believing that the file doesnt exist, and thus
skip any current state lookups for that file. This includes setting
the file_id, and having a valid stat buffer.
Normally on first create the file_id will be set during the open, but
the second opener in this scenario may fail the open (oplock/share mode)
and file_id will not be set, nor will the stat buffer be valid.
In the error paths of this patch, we now double check that the file_id
and the stat buffer are valid before doing other operations.
| -rw-r--r-- | source3/modules/onefs_open.c | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/source3/modules/onefs_open.c b/source3/modules/onefs_open.c index 4ae81356b5..fa1f883c59 100644 --- a/source3/modules/onefs_open.c +++ b/source3/modules/onefs_open.c @@ -824,7 +824,6 @@ NTSTATUS onefs_open_file_ntcreate(connection_struct *conn, DEBUG(10, ("fsp = %p\n", fsp)); - fsp->file_id = vfs_file_id_from_sbuf(conn, &smb_fname->st); fsp->share_access = share_access; fsp->fh->private_options = create_options; fsp->access_mask = open_access_mask; /* We change this to the @@ -929,11 +928,16 @@ NTSTATUS onefs_open_file_ntcreate(connection_struct *conn, SMB_ASSERT(req); if (lck == NULL) { + /* + * We hit the race that when we did the stat + * on the file it did not exist, and someone + * has created it in between the stat and the + * open_file() call. Defer our open waiting, + * to break the oplock of the first opener. + */ struct timespec old_write_time; - old_write_time = smb_fname->st.st_ex_mtime; - DEBUG(3, ("Someone created file %s with an " "oplock after we looked: Retrying\n", smb_fname_str_dbg(smb_fname))); @@ -981,6 +985,16 @@ NTSTATUS onefs_open_file_ntcreate(connection_struct *conn, uint32 can_access_mask; bool can_access = True; + /* If we raced on open we may not have a valid file_id + * or stat buf. Get them again. */ + if (SMB_VFS_STAT(conn, fname, psbuf) == -1) { + DEBUG(0,("Error doing stat on file %s " + "(%s)\n", fname, strerror(errno))); + status = NT_STATUS_SHARING_VIOLATION; + goto cleanup_destroy; + } + id = vfs_file_id_from_sbuf(conn, psbuf); + /* Check if this can be done with the deny_dos and fcb * calls. */ @@ -1135,8 +1149,8 @@ NTSTATUS onefs_open_file_ntcreate(connection_struct *conn, /* * Now the file exists and fsp is successfully opened, - * fsp->dev and fsp->inode are valid and should replace the - * dev=0,inode=0 from a non existent file. Spotted by + * fsp->file_id is valid and should replace the + * dev=0, inode=0 from a non existent file. Spotted by * Nadav Danieli <nadavd@exanet.com>. JRA. */ |