| From 843225aa9d5077bebdb08bbf9699c02aec0b83eb Mon Sep 17 00:00:00 2001 |
| From: "Brian C. Lane" <bcl@redhat.com> |
| Date: Tue, 26 Sep 2017 08:04:58 +0000 |
| Subject: [PATCH] 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 |
| |
| Upstream-Status: Backport |
| |
| Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com> |
| |
| --- |
| libparted/arch/linux.c | 62 +++++++++++++++++++++++++++++++++++--------------- |
| 1 file changed, 44 insertions(+), 18 deletions(-) |
| |
| diff --git a/libparted/arch/linux.c b/libparted/arch/linux.c |
| index 7f12f58..4ddea58 100644 |
| --- a/libparted/arch/linux.c |
| +++ b/libparted/arch/linux.c |
| @@ -292,7 +292,9 @@ struct blkdev_ioctl_param { |
| static char* _device_get_part_path (PedDevice const *dev, int num); |
| static int _partition_is_mounted_by_path (const char* path); |
| static unsigned int _device_get_partition_range(PedDevice const* dev); |
| - |
| +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) |
| @@ -911,7 +913,7 @@ 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)) { |
| @@ -980,11 +982,11 @@ 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; |
| } |
| @@ -1117,7 +1119,7 @@ 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) { |
| @@ -1131,7 +1133,7 @@ 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; |
| } |
| |
| @@ -1153,11 +1155,11 @@ 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; |
| } |
| @@ -1169,7 +1171,7 @@ 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; |
| @@ -1196,7 +1198,7 @@ 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; |
| @@ -1207,7 +1209,7 @@ init_file (PedDevice* dev) |
| return 1; |
| |
| error_close_dev: |
| - ped_device_close (dev); |
| + _device_close (dev); |
| error: |
| return 0; |
| } |
| @@ -1223,7 +1225,7 @@ 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); |
| @@ -1263,11 +1265,11 @@ 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; |
| } |
| @@ -1282,7 +1284,7 @@ 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 (); |
| @@ -1330,11 +1332,11 @@ 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; |
| } |
| @@ -1621,12 +1623,27 @@ 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); |
| @@ -1695,6 +1712,15 @@ 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, |