From 5a7e0a8cf50cf905403f5a498e86d1f97cfcf51b Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Tue, 8 Mar 2011 16:39:46 +0530 Subject: fs/9p: Fix race in initializing writeback fid When two process open the same file we can end up with both of them allocating the writeback_fid. Add a new mutex which can be used for synchronizing v9fs_inode member values. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Venkateswararao Jujjuri Signed-off-by: Eric Van Hensbergen --- fs/9p/vfs_file.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs/9p/vfs_file.c') diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index 78bcb97c3425..3337d58d0fc5 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -90,6 +90,7 @@ int v9fs_file_open(struct inode *inode, struct file *file) } file->private_data = fid; + mutex_lock(&v9inode->v_mutex); if (v9ses->cache && !v9inode->writeback_fid) { /* * clone a fid and add it to writeback_fid @@ -101,10 +102,12 @@ int v9fs_file_open(struct inode *inode, struct file *file) fid = v9fs_writeback_fid(file->f_path.dentry); if (IS_ERR(fid)) { err = PTR_ERR(fid); + mutex_unlock(&v9inode->v_mutex); goto out_error; } v9inode->writeback_fid = (void *) fid; } + mutex_unlock(&v9inode->v_mutex); #ifdef CONFIG_9P_FSCACHE if (v9ses->cache) v9fs_cache_inode_set_cookie(inode, file); -- cgit v1.2.3 From 7add697a3d271aa7080513f92dab190c75174b7e Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Tue, 8 Mar 2011 16:39:49 +0530 Subject: fs/9p: Attach writeback_fid on first open with WR flag We don't need writeback fid if we are only doing O_RDONLY open Signed-off-by: Aneesh Kumar K.V Signed-off-by: Venkateswararao Jujjuri Signed-off-by: Eric Van Hensbergen --- fs/9p/vfs_file.c | 3 ++- fs/9p/vfs_inode.c | 3 ++- fs/9p/vfs_inode_dotl.c | 3 ++- 3 files changed, 6 insertions(+), 3 deletions(-) (limited to 'fs/9p/vfs_file.c') diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index 3337d58d0fc5..6997eb62fbba 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -91,7 +91,8 @@ int v9fs_file_open(struct inode *inode, struct file *file) file->private_data = fid; mutex_lock(&v9inode->v_mutex); - if (v9ses->cache && !v9inode->writeback_fid) { + if (v9ses->cache && !v9inode->writeback_fid && + ((file->f_flags & O_ACCMODE) != O_RDONLY)) { /* * clone a fid and add it to writeback_fid * we do it during open time instead of diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 0afbbb450faf..774a20af01ea 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -652,7 +652,8 @@ v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode, if (nd && nd->flags & LOOKUP_OPEN) { v9inode = V9FS_I(dentry->d_inode); mutex_lock(&v9inode->v_mutex); - if (v9ses->cache && !v9inode->writeback_fid) { + if (v9ses->cache && !v9inode->writeback_fid && + ((flags & O_ACCMODE) != O_RDONLY)) { /* * clone a fid and add it to writeback_fid * we do it during open time instead of diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c index 0a0ac30d51d6..8b616dc3567a 100644 --- a/fs/9p/vfs_inode_dotl.c +++ b/fs/9p/vfs_inode_dotl.c @@ -246,7 +246,8 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, int omode, v9inode = V9FS_I(inode); mutex_lock(&v9inode->v_mutex); - if (v9ses->cache && !v9inode->writeback_fid) { + if (v9ses->cache && !v9inode->writeback_fid && + ((flags & O_ACCMODE) != O_RDONLY)) { /* * clone a fid and add it to writeback_fid * we do it during open time instead of -- cgit v1.2.3 From aaf0ef1d2bce05cfd06cf29c96a6973df4d0a6a8 Mon Sep 17 00:00:00 2001 From: "M. Mohan Kumar" Date: Wed, 16 Mar 2011 21:40:49 +0530 Subject: 9p: use the updated offset given by generic_write_checks Without this fix, even if a file is opened in O_APPEND mode, data will be written at current file position instead of end of file. Signed-off-by: M. Mohan Kumar Reviewed-by: Aneesh Kumar K.V Signed-off-by: Eric Van Hensbergen --- fs/9p/vfs_file.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'fs/9p/vfs_file.c') diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index 6997eb62fbba..ffed55817f0c 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -508,9 +508,12 @@ v9fs_file_write(struct file *filp, const char __user * data, if (!count) goto out; - return v9fs_file_write_internal(filp->f_path.dentry->d_inode, + retval = v9fs_file_write_internal(filp->f_path.dentry->d_inode, filp->private_data, - data, count, offset, 1); + data, count, &origin, 1); + /* update offset on successful write */ + if (retval > 0) + *offset = origin; out: return retval; } -- cgit v1.2.3