From e43ae79c540270865918dab5ac914c74f43101e2 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Tue, 5 Jun 2012 15:10:26 +0200 Subject: 9p: implement i_op->atomic_open() Add an ->atomic_open implementation which replaces the atomic open+create operation implemented via ->create. No functionality is changed. Signed-off-by: Miklos Szeredi CC: Eric Van Hensbergen Signed-off-by: Al Viro --- fs/9p/vfs_inode.c | 169 ++++++++++++++++++++++++++++++++---------------------- 1 file changed, 102 insertions(+), 67 deletions(-) (limited to 'fs/9p/vfs_inode.c') diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 57ccb7537da..e8c42ceb89b 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -712,11 +712,14 @@ error: } /** - * v9fs_vfs_create - VFS hook to create files + * v9fs_vfs_create - VFS hook to create a regular file + * + * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open(). This is only called + * for mknod(2). + * * @dir: directory inode that is being created * @dentry: dentry that is being deleted * @mode: create permissions - * @nd: path information * */ @@ -724,76 +727,19 @@ static int v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, struct nameidata *nd) { - int err; - u32 perm; - int flags; - struct file *filp; - struct v9fs_inode *v9inode; - struct v9fs_session_info *v9ses; - struct p9_fid *fid, *inode_fid; - - err = 0; - fid = NULL; - v9ses = v9fs_inode2v9ses(dir); - perm = unixmode2p9mode(v9ses, mode); - if (nd) - flags = nd->intent.open.flags; - else - flags = O_RDWR; + struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir); + u32 perm = unixmode2p9mode(v9ses, mode); + struct p9_fid *fid; - fid = v9fs_create(v9ses, dir, dentry, NULL, perm, - v9fs_uflags2omode(flags, - v9fs_proto_dotu(v9ses))); - if (IS_ERR(fid)) { - err = PTR_ERR(fid); - fid = NULL; - goto error; - } + /* P9_OEXCL? */ + fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR); + if (IS_ERR(fid)) + return PTR_ERR(fid); v9fs_invalidate_inode_attr(dir); - /* if we are opening a file, assign the open fid to the file */ - if (nd) { - v9inode = V9FS_I(dentry->d_inode); - mutex_lock(&v9inode->v_mutex); - 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 - * page dirty time via write_begin/page_mkwrite - * because we want write after unlink usecase - * to work. - */ - inode_fid = v9fs_writeback_fid(dentry); - if (IS_ERR(inode_fid)) { - err = PTR_ERR(inode_fid); - mutex_unlock(&v9inode->v_mutex); - goto error; - } - v9inode->writeback_fid = (void *) inode_fid; - } - mutex_unlock(&v9inode->v_mutex); - filp = lookup_instantiate_filp(nd, dentry, generic_file_open); - if (IS_ERR(filp)) { - err = PTR_ERR(filp); - goto error; - } - - filp->private_data = fid; -#ifdef CONFIG_9P_FSCACHE - if (v9ses->cache) - v9fs_cache_inode_set_cookie(dentry->d_inode, filp); -#endif - } else - p9_client_clunk(fid); + p9_client_clunk(fid); return 0; - -error: - if (fid) - p9_client_clunk(fid); - - return err; } /** @@ -910,6 +856,93 @@ error: return ERR_PTR(result); } +static struct file * +v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, + struct opendata *od, unsigned flags, umode_t mode, + bool *created) +{ + int err; + u32 perm; + struct file *filp; + struct v9fs_inode *v9inode; + struct v9fs_session_info *v9ses; + struct p9_fid *fid, *inode_fid; + struct dentry *res = NULL; + + if (d_unhashed(dentry)) { + res = v9fs_vfs_lookup(dir, dentry, NULL); + if (IS_ERR(res)) + return ERR_CAST(res); + + if (res) + dentry = res; + } + + /* Only creates */ + if (!(flags & O_CREAT) || dentry->d_inode) { + finish_no_open(od, res); + return NULL; + } + + err = 0; + fid = NULL; + v9ses = v9fs_inode2v9ses(dir); + perm = unixmode2p9mode(v9ses, mode); + fid = v9fs_create(v9ses, dir, dentry, NULL, perm, + v9fs_uflags2omode(flags, + v9fs_proto_dotu(v9ses))); + if (IS_ERR(fid)) { + err = PTR_ERR(fid); + fid = NULL; + goto error; + } + + v9fs_invalidate_inode_attr(dir); + v9inode = V9FS_I(dentry->d_inode); + mutex_lock(&v9inode->v_mutex); + 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 + * page dirty time via write_begin/page_mkwrite + * because we want write after unlink usecase + * to work. + */ + inode_fid = v9fs_writeback_fid(dentry); + if (IS_ERR(inode_fid)) { + err = PTR_ERR(inode_fid); + mutex_unlock(&v9inode->v_mutex); + goto error; + } + v9inode->writeback_fid = (void *) inode_fid; + } + mutex_unlock(&v9inode->v_mutex); + filp = finish_open(od, dentry, generic_file_open); + if (IS_ERR(filp)) { + err = PTR_ERR(filp); + goto error; + } + + filp->private_data = fid; +#ifdef CONFIG_9P_FSCACHE + if (v9ses->cache) + v9fs_cache_inode_set_cookie(dentry->d_inode, filp); +#endif + + *created = true; +out: + dput(res); + return filp; + +error: + if (fid) + p9_client_clunk(fid); + + filp = ERR_PTR(err); + goto out; +} + /** * v9fs_vfs_unlink - VFS unlink hook to delete an inode * @i: inode that is being unlinked @@ -1488,6 +1521,7 @@ out: static const struct inode_operations v9fs_dir_inode_operations_dotu = { .create = v9fs_vfs_create, .lookup = v9fs_vfs_lookup, + .atomic_open = v9fs_vfs_atomic_open, .symlink = v9fs_vfs_symlink, .link = v9fs_vfs_link, .unlink = v9fs_vfs_unlink, @@ -1502,6 +1536,7 @@ static const struct inode_operations v9fs_dir_inode_operations_dotu = { static const struct inode_operations v9fs_dir_inode_operations = { .create = v9fs_vfs_create, .lookup = v9fs_vfs_lookup, + .atomic_open = v9fs_vfs_atomic_open, .unlink = v9fs_vfs_unlink, .mkdir = v9fs_vfs_mkdir, .rmdir = v9fs_vfs_rmdir, -- cgit v1.2.3 From 47237687d73cbeae1dd7a133c3fc3d7239094568 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 10 Jun 2012 05:01:45 -0400 Subject: ->atomic_open() prototype change - pass int * instead of bool * ... and let finish_open() report having opened the file via that sucker. Next step: don't modify od->filp at all. [AV: FILE_CREATE was already used by cifs; Miklos' fix folded] Signed-off-by: Al Viro --- fs/9p/vfs_inode.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'fs/9p/vfs_inode.c') diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index e8c42ceb89b..de626b3b342 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -859,7 +859,7 @@ error: static struct file * v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, struct opendata *od, unsigned flags, umode_t mode, - bool *created) + int *opened) { int err; u32 perm; @@ -918,7 +918,7 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, v9inode->writeback_fid = (void *) inode_fid; } mutex_unlock(&v9inode->v_mutex); - filp = finish_open(od, dentry, generic_file_open); + filp = finish_open(od, dentry, generic_file_open, opened); if (IS_ERR(filp)) { err = PTR_ERR(filp); goto error; @@ -930,7 +930,7 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, v9fs_cache_inode_set_cookie(dentry->d_inode, filp); #endif - *created = true; + *opened |= FILE_CREATED; out: dput(res); return filp; -- cgit v1.2.3 From d95852777bc8ba6b3ad3397d495c5f9dd8ca8383 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 22 Jun 2012 12:39:14 +0400 Subject: make ->atomic_open() return int Change of calling conventions: old new NULL 1 file 0 ERR_PTR(-ve) -ve Caller *knows* that struct file *; no need to return it. Signed-off-by: Al Viro --- fs/9p/vfs_inode.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) (limited to 'fs/9p/vfs_inode.c') diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index de626b3b342..62ce8daefa9 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -856,7 +856,7 @@ error: return ERR_PTR(result); } -static struct file * +static int v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, struct opendata *od, unsigned flags, umode_t mode, int *opened) @@ -872,7 +872,7 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, if (d_unhashed(dentry)) { res = v9fs_vfs_lookup(dir, dentry, NULL); if (IS_ERR(res)) - return ERR_CAST(res); + return PTR_ERR(res); if (res) dentry = res; @@ -881,7 +881,7 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, /* Only creates */ if (!(flags & O_CREAT) || dentry->d_inode) { finish_no_open(od, res); - return NULL; + return 1; } err = 0; @@ -933,13 +933,11 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, *opened |= FILE_CREATED; out: dput(res); - return filp; + return err; error: if (fid) p9_client_clunk(fid); - - filp = ERR_PTR(err); goto out; } -- cgit v1.2.3 From 30d904947459cca2beb69e0110716f5248b31f2a Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 22 Jun 2012 12:40:19 +0400 Subject: kill struct opendata Just pass struct file *. Methods are happier that way... There's no need to return struct file * from finish_open() now, so let it return int. Next: saner prototypes for parts in namei.c Signed-off-by: Al Viro --- fs/9p/vfs_inode.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) (limited to 'fs/9p/vfs_inode.c') diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 62ce8daefa9..2b05651e0c3 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -858,12 +858,11 @@ error: static int v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, - struct opendata *od, unsigned flags, umode_t mode, + struct file *file, unsigned flags, umode_t mode, int *opened) { int err; u32 perm; - struct file *filp; struct v9fs_inode *v9inode; struct v9fs_session_info *v9ses; struct p9_fid *fid, *inode_fid; @@ -880,7 +879,7 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, /* Only creates */ if (!(flags & O_CREAT) || dentry->d_inode) { - finish_no_open(od, res); + finish_no_open(file, res); return 1; } @@ -918,16 +917,14 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, v9inode->writeback_fid = (void *) inode_fid; } mutex_unlock(&v9inode->v_mutex); - filp = finish_open(od, dentry, generic_file_open, opened); - if (IS_ERR(filp)) { - err = PTR_ERR(filp); + err = finish_open(file, dentry, generic_file_open, opened); + if (err) goto error; - } - filp->private_data = fid; + file->private_data = fid; #ifdef CONFIG_9P_FSCACHE if (v9ses->cache) - v9fs_cache_inode_set_cookie(dentry->d_inode, filp); + v9fs_cache_inode_set_cookie(dentry->d_inode, file); #endif *opened |= FILE_CREATED; -- cgit v1.2.3 From e45198a6ac24bd2c4ad4a43b670c2f1a23dd2df3 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 10 Jun 2012 06:48:09 -0400 Subject: make finish_no_open() return int namely, 1 ;-) That's what we want to return from ->atomic_open() instances after finish_no_open(). Signed-off-by: Al Viro --- fs/9p/vfs_inode.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'fs/9p/vfs_inode.c') diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 2b05651e0c3..eae476fb401 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -878,10 +878,8 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, } /* Only creates */ - if (!(flags & O_CREAT) || dentry->d_inode) { - finish_no_open(file, res); - return 1; - } + if (!(flags & O_CREAT) || dentry->d_inode) + return finish_no_open(file, res); err = 0; fid = NULL; -- cgit v1.2.3 From 00cd8dd3bf95f2cc8435b4cac01d9995635c6d0b Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 10 Jun 2012 17:13:09 -0400 Subject: stop passing nameidata to ->lookup() Just the flags; only NFS cares even about that, but there are legitimate uses for such argument. And getting rid of that completely would require splitting ->lookup() into a couple of methods (at least), so let's leave that alone for now... Signed-off-by: Al Viro --- fs/9p/vfs_inode.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'fs/9p/vfs_inode.c') diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index eae476fb401..bb0d7627f95 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -785,7 +785,7 @@ static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode */ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, - struct nameidata *nameidata) + unsigned int flags) { struct dentry *res; struct super_block *sb; @@ -795,8 +795,8 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, char *name; int result = 0; - p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n", - dir, dentry->d_name.name, dentry, nameidata); + p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p flags: %x\n", + dir, dentry->d_name.name, dentry, flags); if (dentry->d_name.len > NAME_MAX) return ERR_PTR(-ENAMETOOLONG); @@ -869,7 +869,7 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, struct dentry *res = NULL; if (d_unhashed(dentry)) { - res = v9fs_vfs_lookup(dir, dentry, NULL); + res = v9fs_vfs_lookup(dir, dentry, 0); if (IS_ERR(res)) return PTR_ERR(res); -- cgit v1.2.3 From ebfc3b49a7ac25920cb5be5445f602e51d2ea559 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 10 Jun 2012 18:05:36 -0400 Subject: don't pass nameidata to ->create() boolean "does it have to be exclusive?" flag is passed instead; Local filesystem should just ignore it - the object is guaranteed not to be there yet. Signed-off-by: Al Viro --- fs/9p/vfs_inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/9p/vfs_inode.c') diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index bb0d7627f95..cbf9dbb1b2a 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -725,7 +725,7 @@ error: static int v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, - struct nameidata *nd) + bool excl) { struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir); u32 perm = unixmode2p9mode(v9ses, mode); -- cgit v1.2.3 From ba413ab2ccc49e6aa1ebc3523a75635b5e4a0494 Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Tue, 21 Aug 2012 09:20:49 +0200 Subject: fs/9p: avoid debug OOPS when reading a long symlink Reading a symlink longer than the given buffer, a p9_debug use would try to print the link name (not NUL-terminated) using a %s format. Use %.*s instead, and replace the strncpy+strnlen with functionally equivalent strlen+memcpy. Signed-off-by: Jim Meyering Signed-off-by: Eric Van Hensbergen --- fs/9p/vfs_inode.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'fs/9p/vfs_inode.c') diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index cbf9dbb1b2a..890bed538f9 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -1276,12 +1276,12 @@ static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen) } /* copy extension buffer into buffer */ - strncpy(buffer, st->extension, buflen); + retval = min(strlen(st->extension)+1, (size_t)buflen); + memcpy(buffer, st->extension, retval); - p9_debug(P9_DEBUG_VFS, "%s -> %s (%s)\n", - dentry->d_name.name, st->extension, buffer); + p9_debug(P9_DEBUG_VFS, "%s -> %s (%.*s)\n", + dentry->d_name.name, st->extension, buflen, buffer); - retval = strnlen(buffer, buflen); done: p9stat_free(st); kfree(st); -- cgit v1.2.3