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Btrfs-progs: Update mtab if necessary when device was deleted in btrfs

PATCH In review Miao Xie 2 participants 4 messages May 31, 2012 – Jun 1, 2012

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Miao Xie

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#0 lore raw

PATCH 1/1 Btrfs-progs: Update mtab if necessary when device was deleted in btrfs

Now if we remove the device that is specified when mounting, btrfs will update the mount information in /proc, such as the information in /proc/mounts. So in order to guarantee the consistency between /etc/mtab and the mount information in /proc, we must update /etc/mtab. This patch does it.

This patch need libmount and libmount-devel(version >= 2.19) packages to compile.

Signed-off-by Chen Yang <[email protected]>
Signed-off-by Miao Xie <[email protected]>
---
 Makefile      |    2 +-
 cmds-device.c |  404 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 utils.h       |    1 +
 3 files changed, 399 insertions(+), 8 deletions(-)
Makefile +1 -1
index 79818e6..8ce415b 100644
@@ -15,7 +15,7 @@ DEPFLAGS = -Wp,-MMD,$(@D)/.$(@F).d,-MT,$@
 INSTALL = install
 prefix ?= /usr/local
 bindir = $(prefix)/bin
-LIBS=-luuid
+LIBS=-luuid -lmount
 RESTORE_LIBS=-lz
 
 progs = btrfsctl mkfs.btrfs btrfs-debug-tree btrfs-show btrfs-vol btrfsck \
cmds-device.c +397 -7

490 lines not on this page · raw message

utils.h +1 -0
index c5f55e1..5a0b9e9 100644
@@ -39,6 +39,7 @@ int btrfs_scan_one_dir(char *dirname, int run_ioctl);
 int check_mounted(const char *devicename);
 int check_mounted_where(int fd, const char *file, char *where, int size,
 			struct btrfs_fs_devices **fs_devices_mnt);
+int blk_file_in_dev_list(struct btrfs_fs_devices *fs_devices, const char *file);
 int btrfs_device_already_in_root(struct btrfs_root *root, int fd,
 				 int super_offset);
 char *pretty_sizes(u64 size);
Signature · 1 line
1.7.6.5
#1 lore raw
Quoted 8 lines · Miao Xie

Now if we remove the device that is specified when mounting, btrfs will update the mount information in /proc, such as the information in /proc/mounts. So in order to guarantee the consistency between /etc/mtab and the mount information in /proc, we must update /etc/mtab. This patch does it.

This patch need libmount and libmount-devel(version >= 2.19) packages to compile.

Does this work well with say Fedora where /etc/mtab is just a symlink to /proc/mounts? Thanks,

Josef

author
#2 lore raw
Quoted 6 lines · Josef Bacik
Quoted 5 lines · Miao Xie

Now if we remove the device that is specified when mounting, btrfs will update the mount information in /proc, such as the information in /proc/mounts. So in order to guarantee the consistency between /etc/mtab and the mount information in /proc, we must update /etc/mtab. This patch does it.

Quoted 6 lines
Quoted 3 lines

This patch need libmount and libmount-devel(version >= 2.19) packages to compile.

Does this work well with say Fedora where /etc/mtab is just a symlink to /proc/mounts? Thanks,

Yes, if /etc/mtab is not a regular file, we will skip the update. And I have do some test for it and all of them passed.

This patch can not work well on your machine?

Thanks
Miao

#3 lore raw
Quoted 11 lines · Miao Xie
Quoted 10 lines · Josef Bacik
Quoted 8 lines · Miao Xie

Now if we remove the device that is specified when mounting, btrfs will update the mount information in /proc, such as the information in /proc/mounts. So in order to guarantee the consistency between /etc/mtab and the mount information in /proc, we must update /etc/mtab. This patch does it.

This patch need libmount and libmount-devel(version >= 2.19) packages to compile.

Quoted 8 lines
Quoted 2 lines

Does this work well with say Fedora where /etc/mtab is just a symlink to /proc/mounts? Thanks,

Yes, if /etc/mtab is not a regular file, we will skip the update. And I have do some test for it and all of them passed.

This patch can not work well on your machine?

It didn't but I think I screwed something up so ignore me. Thanks,

Josef