From d18e9008c377dc6a6d2166a6840bf3a23a5867fd Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Tue, 5 Jun 2012 15:10:17 +0200 Subject: vfs: add i_op->atomic_open() Add a new inode operation which is called on the last component of an open. Using this the filesystem can look up, possibly create and open the file in one atomic operation. If it cannot perform this (e.g. the file type turned out to be wrong) it may signal this by returning NULL instead of an open struct file pointer. i_op->atomic_open() is only called if the last component is negative or needs lookup. Handling cached positive dentries here doesn't add much value: these can be opened using f_op->open(). If the cached file turns out to be invalid, the open can be retried, this time using ->atomic_open() with a fresh dentry. For now leave the old way of using open intents in lookup and revalidate in place. This will be removed once all the users are converted. David Howells noticed that if ->atomic_open() opens the file but does not create it, handle_truncate() will be called on it even if it is not a regular file. Fix this by checking the file type in this case too. Signed-off-by: Miklos Szeredi Signed-off-by: Al Viro --- fs/open.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) (limited to 'fs/open.c') diff --git a/fs/open.c b/fs/open.c index 1540632d8387..13bece4f36a4 100644 --- a/fs/open.c +++ b/fs/open.c @@ -810,6 +810,48 @@ out_err: } EXPORT_SYMBOL_GPL(lookup_instantiate_filp); +/** + * finish_open - finish opening a file + * @od: opaque open data + * @dentry: pointer to dentry + * @open: open callback + * + * This can be used to finish opening a file passed to i_op->atomic_open(). + * + * If the open callback is set to NULL, then the standard f_op->open() + * filesystem callback is substituted. + */ +struct file *finish_open(struct opendata *od, struct dentry *dentry, + int (*open)(struct inode *, struct file *)) +{ + struct file *res; + + mntget(od->mnt); + dget(dentry); + + res = do_dentry_open(dentry, od->mnt, *od->filp, open, current_cred()); + if (!IS_ERR(res)) + *od->filp = NULL; + + return res; +} +EXPORT_SYMBOL(finish_open); + +/** + * finish_no_open - finish ->atomic_open() without opening the file + * + * @od: opaque open data + * @dentry: dentry or NULL (as returned from ->lookup()) + * + * This can be used to set the result of a successful lookup in ->atomic_open(). + * The filesystem's atomic_open() method shall return NULL after calling this. + */ +void finish_no_open(struct opendata *od, struct dentry *dentry) +{ + od->dentry = dentry; +} +EXPORT_SYMBOL(finish_no_open); + /** * nameidata_to_filp - convert a nameidata to an open filp. * @nd: pointer to nameidata -- cgit v1.2.3 From 015c3bbcd88df2305aae5b017a9c91c08b380aa1 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Tue, 5 Jun 2012 15:10:27 +0200 Subject: vfs: remove open intents from nameidata All users of open intents have been converted to use ->atomic_{open,create}. This patch gets rid of nd->intent.open and related infrastructure. Signed-off-by: Miklos Szeredi Signed-off-by: Al Viro --- fs/open.c | 87 ++------------------------------------------------------------- 1 file changed, 2 insertions(+), 85 deletions(-) (limited to 'fs/open.c') diff --git a/fs/open.c b/fs/open.c index 13bece4f36a4..937f4ec20180 100644 --- a/fs/open.c +++ b/fs/open.c @@ -770,46 +770,6 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, return res; } -/** - * lookup_instantiate_filp - instantiates the open intent filp - * @nd: pointer to nameidata - * @dentry: pointer to dentry - * @open: open callback - * - * Helper for filesystems that want to use lookup open intents and pass back - * a fully instantiated struct file to the caller. - * This function is meant to be called from within a filesystem's - * lookup method. - * Beware of calling it for non-regular files! Those ->open methods might block - * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo, - * leading to a deadlock, as nobody can open that fifo anymore, because - * another process to open fifo will block on locked parent when doing lookup). - * Note that in case of error, nd->intent.open.file is destroyed, but the - * path information remains valid. - * If the open callback is set to NULL, then the standard f_op->open() - * filesystem callback is substituted. - */ -struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, - int (*open)(struct inode *, struct file *)) -{ - const struct cred *cred = current_cred(); - - if (IS_ERR(nd->intent.open.file)) - goto out; - if (IS_ERR(dentry)) - goto out_err; - nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt), - nd->intent.open.file, - open, cred); -out: - return nd->intent.open.file; -out_err: - release_open_intent(nd); - nd->intent.open.file = ERR_CAST(dentry); - goto out; -} -EXPORT_SYMBOL_GPL(lookup_instantiate_filp); - /** * finish_open - finish opening a file * @od: opaque open data @@ -829,9 +789,9 @@ struct file *finish_open(struct opendata *od, struct dentry *dentry, mntget(od->mnt); dget(dentry); - res = do_dentry_open(dentry, od->mnt, *od->filp, open, current_cred()); + res = do_dentry_open(dentry, od->mnt, od->filp, open, current_cred()); if (!IS_ERR(res)) - *od->filp = NULL; + od->filp = NULL; return res; } @@ -852,49 +812,6 @@ void finish_no_open(struct opendata *od, struct dentry *dentry) } EXPORT_SYMBOL(finish_no_open); -/** - * nameidata_to_filp - convert a nameidata to an open filp. - * @nd: pointer to nameidata - * @flags: open flags - * - * Note that this function destroys the original nameidata - */ -struct file *nameidata_to_filp(struct nameidata *nd) -{ - const struct cred *cred = current_cred(); - struct file *filp; - - /* Pick up the filp from the open intent */ - filp = nd->intent.open.file; - - /* Has the filesystem initialised the file for us? */ - if (filp->f_path.dentry != NULL) { - nd->intent.open.file = NULL; - } else { - struct file *res; - - path_get(&nd->path); - res = do_dentry_open(nd->path.dentry, nd->path.mnt, - filp, NULL, cred); - if (!IS_ERR(res)) { - int error; - - nd->intent.open.file = NULL; - BUG_ON(res != filp); - - error = open_check_o_direct(filp); - if (error) { - fput(filp); - filp = ERR_PTR(error); - } - } else { - /* Allow nd->intent.open.file to be recycled */ - filp = res; - } - } - return filp; -} - /* * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an * error. -- 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/open.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'fs/open.c') diff --git a/fs/open.c b/fs/open.c index 937f4ec20180..89589bd3993c 100644 --- a/fs/open.c +++ b/fs/open.c @@ -782,7 +782,8 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, * filesystem callback is substituted. */ struct file *finish_open(struct opendata *od, struct dentry *dentry, - int (*open)(struct inode *, struct file *)) + int (*open)(struct inode *, struct file *), + int *opened) { struct file *res; @@ -790,8 +791,10 @@ struct file *finish_open(struct opendata *od, struct dentry *dentry, dget(dentry); res = do_dentry_open(dentry, od->mnt, od->filp, open, current_cred()); - if (!IS_ERR(res)) + if (!IS_ERR(res)) { + *opened |= FILE_OPENED; od->filp = NULL; + } return res; } -- cgit v1.2.3 From 3d8a00d2099ebc6d5a6e95fadaf861709d9919a8 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 10 Jun 2012 05:04:43 -0400 Subject: don't modify od->filp at all make put_filp() conditional on flag set by finish_open() Signed-off-by: Al Viro --- fs/open.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'fs/open.c') diff --git a/fs/open.c b/fs/open.c index 89589bd3993c..c87f98201c29 100644 --- a/fs/open.c +++ b/fs/open.c @@ -786,15 +786,14 @@ struct file *finish_open(struct opendata *od, struct dentry *dentry, int *opened) { struct file *res; + BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */ mntget(od->mnt); dget(dentry); res = do_dentry_open(dentry, od->mnt, od->filp, open, current_cred()); - if (!IS_ERR(res)) { + if (!IS_ERR(res)) *opened |= FILE_OPENED; - od->filp = NULL; - } return res; } -- cgit v1.2.3 From a4a3bdd778715999ddfeefdc52ab76254580fa76 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 10 Jun 2012 05:55:37 -0400 Subject: kill opendata->{mnt,dentry} ->filp->f_path is there for purpose... Signed-off-by: Al Viro --- fs/open.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'fs/open.c') diff --git a/fs/open.c b/fs/open.c index c87f98201c29..2b1654d8bfbd 100644 --- a/fs/open.c +++ b/fs/open.c @@ -788,10 +788,10 @@ struct file *finish_open(struct opendata *od, struct dentry *dentry, struct file *res; BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */ - mntget(od->mnt); + mntget(od->filp->f_path.mnt); dget(dentry); - res = do_dentry_open(dentry, od->mnt, od->filp, open, current_cred()); + res = do_dentry_open(dentry, od->filp->f_path.mnt, od->filp, open, current_cred()); if (!IS_ERR(res)) *opened |= FILE_OPENED; @@ -810,7 +810,7 @@ EXPORT_SYMBOL(finish_open); */ void finish_no_open(struct opendata *od, struct dentry *dentry) { - od->dentry = dentry; + od->filp->f_path.dentry = dentry; } EXPORT_SYMBOL(finish_no_open); -- 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/open.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) (limited to 'fs/open.c') diff --git a/fs/open.c b/fs/open.c index 2b1654d8bfbd..fc829d6c3a4b 100644 --- a/fs/open.c +++ b/fs/open.c @@ -781,21 +781,23 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, * If the open callback is set to NULL, then the standard f_op->open() * filesystem callback is substituted. */ -struct file *finish_open(struct opendata *od, struct dentry *dentry, - int (*open)(struct inode *, struct file *), - int *opened) +int finish_open(struct file *file, struct dentry *dentry, + int (*open)(struct inode *, struct file *), + int *opened) { struct file *res; BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */ - mntget(od->filp->f_path.mnt); + mntget(file->f_path.mnt); dget(dentry); - res = do_dentry_open(dentry, od->filp->f_path.mnt, od->filp, open, current_cred()); - if (!IS_ERR(res)) + res = do_dentry_open(dentry, file->f_path.mnt, file, open, current_cred()); + if (!IS_ERR(res)) { *opened |= FILE_OPENED; + return 0; + } - return res; + return PTR_ERR(res); } EXPORT_SYMBOL(finish_open); @@ -808,9 +810,9 @@ EXPORT_SYMBOL(finish_open); * This can be used to set the result of a successful lookup in ->atomic_open(). * The filesystem's atomic_open() method shall return NULL after calling this. */ -void finish_no_open(struct opendata *od, struct dentry *dentry) +void finish_no_open(struct file *file, struct dentry *dentry) { - od->filp->f_path.dentry = dentry; + file->f_path.dentry = dentry; } EXPORT_SYMBOL(finish_no_open); -- 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/open.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs/open.c') diff --git a/fs/open.c b/fs/open.c index fc829d6c3a4b..d51c1b71b062 100644 --- a/fs/open.c +++ b/fs/open.c @@ -810,9 +810,10 @@ EXPORT_SYMBOL(finish_open); * This can be used to set the result of a successful lookup in ->atomic_open(). * The filesystem's atomic_open() method shall return NULL after calling this. */ -void finish_no_open(struct file *file, struct dentry *dentry) +int finish_no_open(struct file *file, struct dentry *dentry) { file->f_path.dentry = dentry; + return 1; } EXPORT_SYMBOL(finish_no_open); -- cgit v1.2.3 From 96b7e579addd3cdc806c1667bf5b6b126070827c Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 10 Jun 2012 14:22:04 -0400 Subject: switch do_dentry_open() to returning int Signed-off-by: Al Viro --- fs/open.c | 40 ++++++++++++++++++++-------------------- 1 file changed, 20 insertions(+), 20 deletions(-) (limited to 'fs/open.c') diff --git a/fs/open.c b/fs/open.c index d51c1b71b062..1241c597d317 100644 --- a/fs/open.c +++ b/fs/open.c @@ -667,10 +667,10 @@ int open_check_o_direct(struct file *f) return 0; } -static struct file *do_dentry_open(struct dentry *dentry, struct vfsmount *mnt, - struct file *f, - int (*open)(struct inode *, struct file *), - const struct cred *cred) +static int do_dentry_open(struct dentry *dentry, struct vfsmount *mnt, + struct file *f, + int (*open)(struct inode *, struct file *), + const struct cred *cred) { static const struct file_operations empty_fops = {}; struct inode *inode; @@ -699,7 +699,7 @@ static struct file *do_dentry_open(struct dentry *dentry, struct vfsmount *mnt, if (unlikely(f->f_mode & FMODE_PATH)) { f->f_op = &empty_fops; - return f; + return 0; } f->f_op = fops_get(inode->i_fop); @@ -726,7 +726,7 @@ static struct file *do_dentry_open(struct dentry *dentry, struct vfsmount *mnt, file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); - return f; + return 0; cleanup_all: fops_put(f->f_op); @@ -749,7 +749,7 @@ cleanup_all: cleanup_file: dput(dentry); mntput(mnt); - return ERR_PTR(error); + return error; } static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, @@ -757,17 +757,19 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, int (*open)(struct inode *, struct file *), const struct cred *cred) { - struct file *res = do_dentry_open(dentry, mnt, f, open, cred); - if (!IS_ERR(res)) { - int error = open_check_o_direct(f); + int error; + error = do_dentry_open(dentry, mnt, f, open, cred); + if (!error) { + error = open_check_o_direct(f); if (error) { - fput(res); - res = ERR_PTR(error); + fput(f); + f = ERR_PTR(error); } - } else { + } else { put_filp(f); + f = ERR_PTR(error); } - return res; + return f; } /** @@ -785,19 +787,17 @@ int finish_open(struct file *file, struct dentry *dentry, int (*open)(struct inode *, struct file *), int *opened) { - struct file *res; + int error; BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */ mntget(file->f_path.mnt); dget(dentry); - res = do_dentry_open(dentry, file->f_path.mnt, file, open, current_cred()); - if (!IS_ERR(res)) { + error = do_dentry_open(dentry, file->f_path.mnt, file, open, current_cred()); + if (!error) *opened |= FILE_OPENED; - return 0; - } - return PTR_ERR(res); + return error; } EXPORT_SYMBOL(finish_open); -- cgit v1.2.3 From 2a027e7a1873812240cbdac0f55c4734ff0042a5 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 10 Jun 2012 14:24:38 -0400 Subject: fold __dentry_open() into its sole caller Signed-off-by: Al Viro --- fs/open.c | 33 ++++++++++++--------------------- 1 file changed, 12 insertions(+), 21 deletions(-) (limited to 'fs/open.c') diff --git a/fs/open.c b/fs/open.c index 1241c597d317..28fbacbd5e31 100644 --- a/fs/open.c +++ b/fs/open.c @@ -752,26 +752,6 @@ cleanup_file: return error; } -static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, - struct file *f, - int (*open)(struct inode *, struct file *), - const struct cred *cred) -{ - int error; - error = do_dentry_open(dentry, mnt, f, open, cred); - if (!error) { - error = open_check_o_direct(f); - if (error) { - fput(f); - f = ERR_PTR(error); - } - } else { - put_filp(f); - f = ERR_PTR(error); - } - return f; -} - /** * finish_open - finish opening a file * @od: opaque open data @@ -841,7 +821,18 @@ struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags, } f->f_flags = flags; - return __dentry_open(dentry, mnt, f, NULL, cred); + error = do_dentry_open(dentry, mnt, f, NULL, cred); + if (!error) { + error = open_check_o_direct(f); + if (error) { + fput(f); + f = ERR_PTR(error); + } + } else { + put_filp(f); + f = ERR_PTR(error); + } + return f; } EXPORT_SYMBOL(dentry_open); -- cgit v1.2.3 From 02e5180d991f203441687cecd0b7e6a2ba0a34d3 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 10 Jun 2012 14:32:45 -0400 Subject: do_dentry_open(): take initialization of file->f_path to caller ... and get rid of a couple of arguments and a pointless reassignment in finish_open() case. Signed-off-by: Al Viro --- fs/open.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) (limited to 'fs/open.c') diff --git a/fs/open.c b/fs/open.c index 28fbacbd5e31..124ccb1d38a0 100644 --- a/fs/open.c +++ b/fs/open.c @@ -667,8 +667,7 @@ int open_check_o_direct(struct file *f) return 0; } -static int do_dentry_open(struct dentry *dentry, struct vfsmount *mnt, - struct file *f, +static int do_dentry_open(struct file *f, int (*open)(struct inode *, struct file *), const struct cred *cred) { @@ -682,9 +681,9 @@ static int do_dentry_open(struct dentry *dentry, struct vfsmount *mnt, if (unlikely(f->f_flags & O_PATH)) f->f_mode = FMODE_PATH; - inode = dentry->d_inode; + inode = f->f_path.dentry->d_inode; if (f->f_mode & FMODE_WRITE) { - error = __get_file_write_access(inode, mnt); + error = __get_file_write_access(inode, f->f_path.mnt); if (error) goto cleanup_file; if (!special_file(inode->i_mode)) @@ -692,8 +691,6 @@ static int do_dentry_open(struct dentry *dentry, struct vfsmount *mnt, } f->f_mapping = inode->i_mapping; - f->f_path.dentry = dentry; - f->f_path.mnt = mnt; f->f_pos = 0; file_sb_list_add(f, inode->i_sb); @@ -740,15 +737,14 @@ cleanup_all: * here, so just reset the state. */ file_reset_write(f); - mnt_drop_write(mnt); + mnt_drop_write(f->f_path.mnt); } } file_sb_list_del(f); - f->f_path.dentry = NULL; - f->f_path.mnt = NULL; cleanup_file: - dput(dentry); - mntput(mnt); + path_put(&f->f_path); + f->f_path.mnt = NULL; + f->f_path.dentry = NULL; return error; } @@ -771,9 +767,9 @@ int finish_open(struct file *file, struct dentry *dentry, BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */ mntget(file->f_path.mnt); - dget(dentry); + file->f_path.dentry = dget(dentry); - error = do_dentry_open(dentry, file->f_path.mnt, file, open, current_cred()); + error = do_dentry_open(file, open, current_cred()); if (!error) *opened |= FILE_OPENED; @@ -821,7 +817,9 @@ struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags, } f->f_flags = flags; - error = do_dentry_open(dentry, mnt, f, NULL, cred); + f->f_path.mnt = mnt; + f->f_path.dentry = dentry; + error = do_dentry_open(f, NULL, cred); if (!error) { error = open_check_o_direct(f); if (error) { -- cgit v1.2.3 From c3c4f69424db0760239762d36d0b1b6ae524008b Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 23 Jun 2012 22:49:45 +0400 Subject: do_dentry_open(): close the race with mark_files_ro() in failure exit we want to take it out of mark_files_ro() reach *before* we start checking if we ought to drop write access. Signed-off-by: Al Viro --- fs/open.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/open.c') diff --git a/fs/open.c b/fs/open.c index 124ccb1d38a0..764cc9c201a5 100644 --- a/fs/open.c +++ b/fs/open.c @@ -727,6 +727,7 @@ static int do_dentry_open(struct file *f, cleanup_all: fops_put(f->f_op); + file_sb_list_del(f); if (f->f_mode & FMODE_WRITE) { put_write_access(inode); if (!special_file(inode->i_mode)) { @@ -740,7 +741,6 @@ cleanup_all: mnt_drop_write(f->f_path.mnt); } } - file_sb_list_del(f); cleanup_file: path_put(&f->f_path); f->f_path.mnt = NULL; -- cgit v1.2.3 From 55e4def0a6e79e7eb53017c4935adfed76510cd7 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 25 Jun 2012 12:55:09 +0100 Subject: VFS: Make chown() and lchown() call fchownat() Make the chown() and lchown() syscalls jump to the fchownat() syscall with the appropriate extra arguments. Signed-off-by: David Howells Signed-off-by: Al Viro --- fs/open.c | 41 +++++++---------------------------------- 1 file changed, 7 insertions(+), 34 deletions(-) (limited to 'fs/open.c') diff --git a/fs/open.c b/fs/open.c index 764cc9c201a5..75bea868ef8a 100644 --- a/fs/open.c +++ b/fs/open.c @@ -537,25 +537,6 @@ static int chown_common(struct path *path, uid_t user, gid_t group) return error; } -SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) -{ - struct path path; - int error; - - error = user_path(filename, &path); - if (error) - goto out; - error = mnt_want_write(path.mnt); - if (error) - goto out_release; - error = chown_common(&path, user, group); - mnt_drop_write(path.mnt); -out_release: - path_put(&path); -out: - return error; -} - SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, gid_t, group, int, flag) { @@ -583,23 +564,15 @@ out: return error; } -SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group) +SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) { - struct path path; - int error; + return sys_fchownat(AT_FDCWD, filename, user, group, 0); +} - error = user_lpath(filename, &path); - if (error) - goto out; - error = mnt_want_write(path.mnt); - if (error) - goto out_release; - error = chown_common(&path, user, group); - mnt_drop_write(path.mnt); -out_release: - path_put(&path); -out: - return error; +SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group) +{ + return sys_fchownat(AT_FDCWD, filename, user, group, + AT_SYMLINK_NOFOLLOW); } SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) -- cgit v1.2.3 From 765927b2d508712d320c8934db963bbe14c3fcec Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 26 Jun 2012 21:58:53 +0400 Subject: switch dentry_open() to struct path, make it grab references itself Signed-off-by: Al Viro --- fs/open.c | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-) (limited to 'fs/open.c') diff --git a/fs/open.c b/fs/open.c index 75bea868ef8a..1e914b397e12 100644 --- a/fs/open.c +++ b/fs/open.c @@ -766,11 +766,7 @@ int finish_no_open(struct file *file, struct dentry *dentry) } EXPORT_SYMBOL(finish_no_open); -/* - * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an - * error. - */ -struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags, +struct file *dentry_open(const struct path *path, int flags, const struct cred *cred) { int error; @@ -779,19 +775,16 @@ struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags, validate_creds(cred); /* We must always pass in a valid mount pointer. */ - BUG_ON(!mnt); + BUG_ON(!path->mnt); error = -ENFILE; f = get_empty_filp(); - if (f == NULL) { - dput(dentry); - mntput(mnt); + if (f == NULL) return ERR_PTR(error); - } f->f_flags = flags; - f->f_path.mnt = mnt; - f->f_path.dentry = dentry; + f->f_path = *path; + path_get(&f->f_path); error = do_dentry_open(f, NULL, cred); if (!error) { error = open_check_o_direct(f); -- cgit v1.2.3