From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1a7L7z-0004Cr-ES for barebox@lists.infradead.org; Fri, 11 Dec 2015 10:40:44 +0000 From: Sascha Hauer Date: Fri, 11 Dec 2015 11:40:34 +0100 Message-Id: <1449830435-6964-1-git-send-email-s.hauer@pengutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH 1/2] devfs: Add symlink support To: Barebox List Signed-off-by: Sascha Hauer --- fs/devfs-core.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++---------- fs/devfs.c | 27 ++++++++++++++++++++- include/driver.h | 4 ++++ 3 files changed, 89 insertions(+), 14 deletions(-) diff --git a/fs/devfs-core.c b/fs/devfs-core.c index 2541ea3..1e899a1 100644 --- a/fs/devfs-core.c +++ b/fs/devfs-core.c @@ -46,7 +46,18 @@ int devfs_partition_complete(struct string_list *sl, char *instr) } #endif -struct cdev *cdev_by_name(const char *filename) +struct cdev *cdev_readlink(struct cdev *cdev) +{ + if (cdev->link) + cdev = cdev->link; + + /* links to links are not allowed */ + BUG_ON(cdev->link); + + return cdev; +} + +struct cdev *lcdev_by_name(const char *filename) { struct cdev *cdev; @@ -57,6 +68,17 @@ struct cdev *cdev_by_name(const char *filename) return NULL; } +struct cdev *cdev_by_name(const char *filename) +{ + struct cdev *cdev; + + cdev = lcdev_by_name(filename); + if (!cdev) + return NULL; + + return cdev_readlink(cdev); +} + struct cdev *cdev_by_device_node(struct device_node *node) { struct cdev *cdev; @@ -65,7 +87,7 @@ struct cdev *cdev_by_device_node(struct device_node *node) if (!cdev->device_node) continue; if (cdev->device_node == node) - return cdev; + return cdev_readlink(cdev); } return NULL; } @@ -111,14 +133,6 @@ int cdev_find_free_index(const char *basename) return -EBUSY; /* all indexes are used */ } -int cdev_do_open(struct cdev *cdev, unsigned long flags) -{ - if (cdev->ops->open) - return cdev->ops->open(cdev, flags); - - return 0; -} - struct cdev *cdev_open(const char *name, unsigned long flags) { struct cdev *cdev; @@ -131,9 +145,11 @@ struct cdev *cdev_open(const char *name, unsigned long flags) if (!cdev) return NULL; - ret = cdev_do_open(cdev, flags); - if (ret) - return NULL; + if (cdev->ops->open) { + ret = cdev->ops->open(cdev, flags); + if (ret) + return NULL; + } return cdev; } @@ -266,8 +282,31 @@ int devfs_create(struct cdev *new) return 0; } +int devfs_create_link(struct cdev *cdev, const char *name) +{ + struct cdev *new; + + if (cdev_by_name(name)) + return -EEXIST; + + /* + * Create a link to the real cdev instead of creating + * a link to a link. + */ + cdev = cdev_readlink(cdev); + + new = xzalloc(sizeof(*new)); + new->name = xstrdup(name); + new->link = cdev; + list_add_tail(&new->list, &cdev_list); + + return 0; +} + int devfs_remove(struct cdev *cdev) { + struct cdev *c, *tmp; + if (cdev->open) return -EBUSY; @@ -275,6 +314,13 @@ int devfs_remove(struct cdev *cdev) if (cdev->dev) list_del(&cdev->devices_list); + list_for_each_entry_safe(c, tmp, &cdev_list, list) + if (c->link == cdev) + devfs_remove(c); + + if (cdev->link) + free(cdev); + return 0; } diff --git a/fs/devfs.c b/fs/devfs.c index 5c96682..0b8d4fd 100644 --- a/fs/devfs.c +++ b/fs/devfs.c @@ -212,12 +212,18 @@ static int devfs_stat(struct device_d *_dev, const char *filename, struct stat * { struct cdev *cdev; - cdev = cdev_by_name(filename + 1); + cdev = lcdev_by_name(filename + 1); if (!cdev) return -ENOENT; s->st_mode = S_IFCHR; s->st_size = cdev->size; + + if (cdev->link) + s->st_mode |= S_IFLNK; + + cdev = cdev_readlink(cdev); + if (cdev->ops->write) s->st_mode |= S_IWUSR; if (cdev->ops->read) @@ -242,6 +248,24 @@ static void devfs_delete(struct device_d *dev) { } +static int devfs_readlink(struct device_d *dev, const char *pathname, + char *buf, size_t bufsz) +{ + struct cdev *cdev; + + cdev = cdev_by_name(pathname + 1); + if (!cdev) + return -ENOENT; + + while (cdev->link) + cdev = cdev->link; + + bufsz = min(bufsz, strlen(cdev->name)); + memcpy(buf, cdev->name, bufsz); + + return 0; +} + static struct fs_driver_d devfs_driver = { .read = devfs_read, .write = devfs_write, @@ -258,6 +282,7 @@ static struct fs_driver_d devfs_driver = { .erase = devfs_erase, .protect = devfs_protect, .memmap = devfs_memmap, + .readlink = devfs_readlink, .flags = FS_DRIVER_NO_DEV, .drv = { .probe = devfs_probe, diff --git a/include/driver.h b/include/driver.h index 046dd90..29686f5 100644 --- a/include/driver.h +++ b/include/driver.h @@ -450,13 +450,17 @@ struct cdev { int open; struct mtd_info *mtd; u8 dos_partition_type; + struct cdev *link; }; int devfs_create(struct cdev *); +int devfs_create_link(struct cdev *, const char *name); int devfs_remove(struct cdev *); int cdev_find_free_index(const char *); struct cdev *device_find_partition(struct device_d *dev, const char *name); struct cdev *cdev_by_name(const char *filename); +struct cdev *lcdev_by_name(const char *filename); +struct cdev *cdev_readlink(struct cdev *cdev); struct cdev *cdev_by_device_node(struct device_node *node); struct cdev *cdev_open(const char *name, unsigned long flags); int cdev_do_open(struct cdev *, unsigned long flags); -- 2.6.2 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox