From: Eric Sandeen Date: Tue, 23 Jun 2015 01:36:50 +0000 (+1000) Subject: xfs_repair: refuse to unset lazycount on V5 filesystems X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=66de82b8c149b312c1c38dd2bcb5310096ce76e9;p=users%2Fhch%2Fxfsprogs.git xfs_repair: refuse to unset lazycount on V5 filesystems Running "xfs_admin -c 0" on a V5 fs has unfortunate results. Before: versionnum [0xbca5+0x18a] = ... LAZYSBCOUNT,PROJID32BIT,CRC, ... After: versionnum [0xbca5+0x188] = ... LAZYSBCOUNT,PROJID32BIT,CRC, ... The on-disk feature bit is in fact changed, but xfs_db reports that the feature is still present. This is because xfs_sb_version_haslazysbcount() ignores the feature bit, and always reports that the lazy-count feature is present on a V5 fs. i.e. the intent is that this feature is not optional on a V5 fs, yet we still flip the bit on disk when asked. Not good. So, document this, and error out if the user tries to disable lazy-count on a version 5 filesystem. Reported-by: Richard W.M. Jones Signed-off-by: Eric Sandeen Reviewed-by: Brian Foster Signed-off-by: Dave Chinner --- diff --git a/man/man8/xfs_admin.8 b/man/man8/xfs_admin.8 index b393d7446..0968196d0 100644 --- a/man/man8/xfs_admin.8 +++ b/man/man8/xfs_admin.8 @@ -62,6 +62,10 @@ Print the current filesystem UUID (Universally Unique IDentifier). .TP .BR "\-c 0" | 1 Enable (1) or disable (0) lazy-counters in the filesystem. +.IP +Lazy-counters may not be disabled on Version 5 superblock filesystems +(i.e. those with metadata CRCs enabled). +.IP This operation may take quite a bit of time on large filesystems as the entire filesystem needs to be scanned when this option is changed. .IP diff --git a/repair/phase1.c b/repair/phase1.c index ec75ada59..9e7011db5 100644 --- a/repair/phase1.c +++ b/repair/phase1.c @@ -121,8 +121,12 @@ phase1(xfs_mount_t *mp) sb->sb_bad_features2 |= XFS_SB_VERSION2_LAZYSBCOUNTBIT; primary_sb_modified = 1; printf(_("Enabling lazy-counters\n")); - } else - if (!lazy_count && xfs_sb_version_haslazysbcount(sb)) { + } else if (!lazy_count && xfs_sb_version_haslazysbcount(sb)) { + if (XFS_SB_VERSION_NUM(sb) == XFS_SB_VERSION_5) { + printf( +_("Cannot disable lazy-counters on V5 fs\n")); + exit(1); + } sb->sb_features2 &= ~XFS_SB_VERSION2_LAZYSBCOUNTBIT; sb->sb_bad_features2 &= ~XFS_SB_VERSION2_LAZYSBCOUNTBIT; printf(_("Disabling lazy-counters\n"));