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path: root/fs/ext4/mmp.c
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2013-01-12ext4: use unlikely to improve the efficiency of the kernelWang Shilong
Because the function 'sb_getblk' seldomly fails to return NULL value,it will be better to use 'unlikely' to optimize it. Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-01-12ext4: return ENOMEM if sb_getblk() failsTheodore Ts'o
The only reason for sb_getblk() failing is if it can't allocate the buffer_head. So ENOMEM is more appropriate than EIO. In addition, make sure that the file system is marked as being inconsistent if sb_getblk() fails. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@vger.kernel.org
2012-07-31ext4: Convert to new freezing mechanismJan Kara
We remove most of frozen checks since upper layer takes care of blocking all writes. We have to handle protection in ext4_page_mkwrite() in a special way because we cannot use generic block_page_mkwrite(). Also we add a freeze protection to ext4_evict_inode() so that iput() of unlinked inode cannot modify a frozen filesystem (we cannot easily instrument ext4_journal_start() / ext4_journal_stop() with freeze protection because we are missing the superblock pointer in ext4_journal_stop() in nojournal mode). CC: linux-ext4@vger.kernel.org CC: "Theodore Ts'o" <tytso@mit.edu> BugLink: https://bugs.launchpad.net/bugs/897421 Tested-by: Kamal Mostafa <kamal@canonical.com> Tested-by: Peter M. Petrakis <peter.petrakis@canonical.com> Tested-by: Dann Frazier <dann.frazier@canonical.com> Tested-by: Massimo Morana <massimo.morana@canonical.com> Acked-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-04-29ext4: add checksums to the MMP blockDarrick J. Wong
Compute and verify a checksum for the MMP block. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-02-27ext4: Fix endianness bug when reading the MMP blockSantosh Nayak
Sparse complained about this endian bug in fs/ext4/mmp.c. Signed-off-by: Santosh Nayak <santoshprasadnayak@gmail.com> Reviewed-by: Johann Lombardi <johann@whamcloud.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-18ext4: Fix comparison endianness problem in MMP initializationDarrick J. Wong
As part of startup, the MMP initialization code does this: mmp->mmp_seq = seq = cpu_to_le32(mmp_new_seq()); Next, mmp->mmp_seq is written out to disk, a delay happens, and then the MMP block is read back in and the sequence value is tested: if (seq != le32_to_cpu(mmp->mmp_seq)) { /* fail the mount */ On a LE system such as x86, the *le32* functions do nothing and this works. Unfortunately, on a BE system such as ppc64, this comparison becomes: if (cpu_to_le32(new_seq) != le32_to_cpu(cpu_to_le32(new_seq)) { /* fail the mount */ Except for a few palindromic sequence numbers, this test always causes the mount to fail, which makes MMP filesystems generally unmountable on ppc64. The attached patch fixes this situation. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-18ext4: MMP: fix error message rate-limiting logic in kmmpdNikitas Angelinas
Current logic would print an error message only once, and then 'failed_writes' would stay at 1. Rework the loop to increment 'failed_writes' and print the error message every s_mmp_update_interval * 60 seconds, as intended according to the comment. Signed-off-by: Nikitas Angelinas <nikitas_angelinas@xyratex.com> Signed-off-by: Andrew Perepechko <andrew_perepechko@xyratex.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Acked-by: Andreas Dilger <adilger@dilger.ca>
2011-10-18ext4: MMP: kmmpd should use nodename from init_uts_ns.name, not sysnameNikitas Angelinas
sysname holds "Linux" by default, i.e. what appears when doing a "uname -s"; nodename should be used to print the machine's hostname, i.e. what is returned when doing a "uname -n" or "hostname", and what gethostname(2)/sethostname(2) manipulate, in order to notify the administrator of the node which is contending to mount the filesystem. Acked-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Nikitas Angelinas <nikitas_angelinas@xyratex.com> Signed-off-by: Andrew Perepechko <andrew_perepechko@xyratex.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-05-24ext4: add support for multiple mount protectionJohann Lombardi
Prevent an ext4 filesystem from being mounted multiple times. A sequence number is stored on disk and is periodically updated (every 5 seconds by default) by a mounted filesystem. At mount time, we now wait for s_mmp_update_interval seconds to make sure that the MMP sequence does not change. In case of failure, the nodename, bdevname and the time at which the MMP block was last updated is displayed. Signed-off-by: Andreas Dilger <adilger@whamcloud.com> Signed-off-by: Johann Lombardi <johann@whamcloud.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>