From 468d537b07c3c1ad72e1ee1e9651a17c72038837 Mon Sep 17 00:00:00 2001 From: Fedora Ninjas Date: Thu, 6 Aug 2015 07:17:14 -0700 Subject: [PATCH 33/35] libparted: Use read only when probing devices on linux (#1245144) When a device is opened for RW closing it can trigger other actions, like udev scanning it for partition changes. Use read only for the init_* methods and RW for actual changes to the device. This adds _device_open which takes mode flags as an argument and turns linux_open into a wrapper for it with RW_MODE. _device_open_ro is added to open the device with RD_MODE and increment the open_counter. This is used in the init_* functions. _device_close is a wrapper around linux_close that decrements the open_counter and is used in the init_* functions. All of these changes are self-contained with no external API changes. The only visible change in behavior is that when a new PedDevice is created the device is opened in RO_MODE instead of RW_MODE. Resolves: rhbz#1245144 --- libparted/arch/linux.c | 61 ++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 44 insertions(+), 17 deletions(-) diff --git a/libparted/arch/linux.c b/libparted/arch/linux.c index 1d11f58..341bbbb 100644 --- a/libparted/arch/linux.c +++ b/libparted/arch/linux.c @@ -287,6 +287,9 @@ struct blkdev_ioctl_param { static char* _device_get_part_path (PedDevice* dev, int num); static int _partition_is_mounted_by_path (const char* path); +static int _device_open (PedDevice* dev, int flags); +static int _device_open_ro (PedDevice* dev); +static int _device_close (PedDevice* dev); static int _read_fd (int fd, char **buf) @@ -830,7 +833,7 @@ init_ide (PedDevice* dev) if (!_device_stat (dev, &dev_stat)) goto error; - if (!ped_device_open (dev)) + if (!_device_open_ro (dev)) goto error; if (ioctl (arch_specific->fd, HDIO_GET_IDENTITY, &hdi)) { @@ -899,11 +902,11 @@ init_ide (PedDevice* dev) if (!_device_probe_geometry (dev)) goto error_close_dev; - ped_device_close (dev); + _device_close (dev); return 1; error_close_dev: - ped_device_close (dev); + _device_close (dev); error: return 0; } @@ -1036,7 +1039,7 @@ init_scsi (PedDevice* dev) char* vendor; char* product; - if (!ped_device_open (dev)) + if (!_device_open_ro (dev)) goto error; if (ioctl (arch_specific->fd, SCSI_IOCTL_GET_IDLUN, &idlun) < 0) { @@ -1050,7 +1053,7 @@ init_scsi (PedDevice* dev) goto error_close_dev; if (!_device_probe_geometry (dev)) goto error_close_dev; - ped_device_close (dev); + _device_close (dev); return 1; } @@ -1072,11 +1075,11 @@ init_scsi (PedDevice* dev) if (!_device_probe_geometry (dev)) goto error_close_dev; - ped_device_close (dev); + _device_close (dev); return 1; error_close_dev: - ped_device_close (dev); + _device_close (dev); error: return 0; } @@ -1088,7 +1091,7 @@ init_file (PedDevice* dev) if (!_device_stat (dev, &dev_stat)) goto error; - if (!ped_device_open (dev)) + if (!_device_open_ro (dev)) goto error; dev->sector_size = PED_SECTOR_SIZE_DEFAULT; @@ -1115,7 +1118,7 @@ init_file (PedDevice* dev) goto error_close_dev; } - ped_device_close (dev); + _device_close (dev); dev->bios_geom.cylinders = dev->length / 4 / 32; dev->bios_geom.heads = 4; @@ -1126,7 +1129,7 @@ init_file (PedDevice* dev) return 1; error_close_dev: - ped_device_close (dev); + _device_close (dev); error: return 0; } @@ -1142,7 +1145,7 @@ init_dasd (PedDevice* dev, const char* model_name) if (!_device_stat (dev, &dev_stat)) goto error; - if (!ped_device_open (dev)) + if (!_device_open_ro (dev)) goto error; LinuxSpecific* arch_specific = LINUX_SPECIFIC (dev); @@ -1182,11 +1185,11 @@ init_dasd (PedDevice* dev, const char* model_name) dev->model = strdup (model_name); - ped_device_close (dev); + _device_close (dev); return 1; error_close_dev: - ped_device_close (dev); + _device_close (dev); error: return 0; } @@ -1201,7 +1204,7 @@ init_generic (PedDevice* dev, const char* model_name) if (!_device_stat (dev, &dev_stat)) goto error; - if (!ped_device_open (dev)) + if (!_device_open_ro (dev)) goto error; ped_exception_fetch_all (); @@ -1249,11 +1252,11 @@ init_generic (PedDevice* dev, const char* model_name) dev->model = strdup (model_name); - ped_device_close (dev); + _device_close (dev); return 1; error_close_dev: - ped_device_close (dev); + _device_close (dev); error: return 0; } @@ -1543,12 +1546,27 @@ retry: } static int +_device_open_ro (PedDevice* dev) +{ + int rc = _device_open (dev, RD_MODE); + if (rc) + dev->open_count++; + return rc; +} + +static int linux_open (PedDevice* dev) { + return _device_open (dev, RW_MODE); +} + +static int +_device_open (PedDevice* dev, int flags) +{ LinuxSpecific* arch_specific = LINUX_SPECIFIC (dev); retry: - arch_specific->fd = open (dev->path, RW_MODE); + arch_specific->fd = open (dev->path, flags); if (arch_specific->fd == -1) { char* rw_error_msg = strerror (errno); @@ -1617,6 +1635,15 @@ linux_refresh_close (PedDevice* dev) return 1; } +static int +_device_close (PedDevice* dev) +{ + int rc = linux_close (dev); + if (dev->open_count > 0) + dev->open_count--; + return rc; +} + #if SIZEOF_OFF_T < 8 static _syscall5(int,_llseek, -- 2.4.3