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authorJan Kara <jack@suse.cz>2013-12-08 21:11:59 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-01-09 12:24:21 -0800
commitb35e443037c2e162a015a5f46009e8c21e673b63 (patch)
treefbfb0a36bfdc28c50898d05e29458e21f883ebce /fs/ext4
parentae21dda05193c441bde106a4bbf88c185a68fbed (diff)
ext4: Do not reserve clusters when fs doesn't support extents
commit 30fac0f75da24dd5bb43c9e911d2039a984ac815 upstream. When the filesystem doesn't support extents (like in ext2/3 compatibility modes), there is no need to reserve any clusters. Space estimates for writing are exact, hole punching doesn't need new metadata, and there are no unwritten extents to convert. This fixes a problem when filesystem still having some free space when accessed with a native ext2/3 driver suddently reports ENOSPC when accessed with ext4 driver. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/super.c17
1 files changed, 13 insertions, 4 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 3f7c39e6d097..e4923b6a9e39 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3213,11 +3213,19 @@ int ext4_calculate_overhead(struct super_block *sb)
}
-static ext4_fsblk_t ext4_calculate_resv_clusters(struct ext4_sb_info *sbi)
+static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
{
ext4_fsblk_t resv_clusters;
/*
+ * There's no need to reserve anything when we aren't using extents.
+ * The space estimates are exact, there are no unwritten extents,
+ * hole punching doesn't need new metadata... This is needed especially
+ * to keep ext2/3 backward compatibility.
+ */
+ if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
+ return 0;
+ /*
* By default we reserve 2% or 4096 clusters, whichever is smaller.
* This should cover the situations where we can not afford to run
* out of space like for example punch hole, or converting
@@ -3225,7 +3233,8 @@ static ext4_fsblk_t ext4_calculate_resv_clusters(struct ext4_sb_info *sbi)
* allocation would require 1, or 2 blocks, higher numbers are
* very rare.
*/
- resv_clusters = ext4_blocks_count(sbi->s_es) >> sbi->s_cluster_bits;
+ resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
+ EXT4_SB(sb)->s_cluster_bits;
do_div(resv_clusters, 50);
resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
@@ -3969,10 +3978,10 @@ no_journal:
"available");
}
- err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sbi));
+ err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
if (err) {
ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
- "reserved pool", ext4_calculate_resv_clusters(sbi));
+ "reserved pool", ext4_calculate_resv_clusters(sb));
goto failed_mount4a;
}