5.4-stable review patch. If anyone has any objections, please let me know.
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From: Theodore Ts'o tytso@mit.edu
commit 4a622e4d477bb12ad5ed4abbc7ad1365de1fa347 upstream.
The original implementation ext4's FS_IOC_GETFSMAP handling only worked when the range of queried blocks included at least one free (unallocated) block range. This is because how the metadata blocks were emitted was as a side effect of ext4_mballoc_query_range() calling ext4_getfsmap_datadev_helper(), and that function was only called when a free block range was identified. As a result, this caused generic/365 to fail.
Fix this by creating a new function ext4_getfsmap_meta_helper() which gets called so that blocks before the first free block range in a block group can get properly reported.
Signed-off-by: Theodore Ts'o tytso@mit.edu Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ext4/fsmap.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++++- fs/ext4/mballoc.c | 18 ++++++++++++++---- fs/ext4/mballoc.h | 1 + 3 files changed, 68 insertions(+), 5 deletions(-)
--- a/fs/ext4/fsmap.c +++ b/fs/ext4/fsmap.c @@ -185,6 +185,56 @@ static inline ext4_fsblk_t ext4_fsmap_ne return fmr->fmr_physical + fmr->fmr_length; }
+static int ext4_getfsmap_meta_helper(struct super_block *sb, + ext4_group_t agno, ext4_grpblk_t start, + ext4_grpblk_t len, void *priv) +{ + struct ext4_getfsmap_info *info = priv; + struct ext4_fsmap *p; + struct ext4_fsmap *tmp; + struct ext4_sb_info *sbi = EXT4_SB(sb); + ext4_fsblk_t fsb, fs_start, fs_end; + int error; + + fs_start = fsb = (EXT4_C2B(sbi, start) + + ext4_group_first_block_no(sb, agno)); + fs_end = fs_start + EXT4_C2B(sbi, len); + + /* Return relevant extents from the meta_list */ + list_for_each_entry_safe(p, tmp, &info->gfi_meta_list, fmr_list) { + if (p->fmr_physical < info->gfi_next_fsblk) { + list_del(&p->fmr_list); + kfree(p); + continue; + } + if (p->fmr_physical <= fs_start || + p->fmr_physical + p->fmr_length <= fs_end) { + /* Emit the retained free extent record if present */ + if (info->gfi_lastfree.fmr_owner) { + error = ext4_getfsmap_helper(sb, info, + &info->gfi_lastfree); + if (error) + return error; + info->gfi_lastfree.fmr_owner = 0; + } + error = ext4_getfsmap_helper(sb, info, p); + if (error) + return error; + fsb = p->fmr_physical + p->fmr_length; + if (info->gfi_next_fsblk < fsb) + info->gfi_next_fsblk = fsb; + list_del(&p->fmr_list); + kfree(p); + continue; + } + } + if (info->gfi_next_fsblk < fsb) + info->gfi_next_fsblk = fsb; + + return 0; +} + + /* Transform a blockgroup's free record into a fsmap */ static int ext4_getfsmap_datadev_helper(struct super_block *sb, ext4_group_t agno, ext4_grpblk_t start, @@ -539,6 +589,7 @@ static int ext4_getfsmap_datadev(struct error = ext4_mballoc_query_range(sb, info->gfi_agno, EXT4_B2C(sbi, info->gfi_low.fmr_physical), EXT4_B2C(sbi, info->gfi_high.fmr_physical), + ext4_getfsmap_meta_helper, ext4_getfsmap_datadev_helper, info); if (error) goto err; @@ -560,7 +611,8 @@ static int ext4_getfsmap_datadev(struct
/* Report any gaps at the end of the bg */ info->gfi_last = true; - error = ext4_getfsmap_datadev_helper(sb, end_ag, last_cluster, 0, info); + error = ext4_getfsmap_datadev_helper(sb, end_ag, last_cluster + 1, + 0, info); if (error) goto err;
--- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -5432,13 +5432,14 @@ int ext4_mballoc_query_range( struct super_block *sb, ext4_group_t group, - ext4_grpblk_t start, + ext4_grpblk_t first, ext4_grpblk_t end, + ext4_mballoc_query_range_fn meta_formatter, ext4_mballoc_query_range_fn formatter, void *priv) { void *bitmap; - ext4_grpblk_t next; + ext4_grpblk_t start, next; struct ext4_buddy e4b; int error;
@@ -5449,10 +5450,19 @@ ext4_mballoc_query_range(
ext4_lock_group(sb, group);
- start = max(e4b.bd_info->bb_first_free, start); + start = max(e4b.bd_info->bb_first_free, first); if (end >= EXT4_CLUSTERS_PER_GROUP(sb)) end = EXT4_CLUSTERS_PER_GROUP(sb) - 1; - + if (meta_formatter && start != first) { + if (start > end) + start = end; + ext4_unlock_group(sb, group); + error = meta_formatter(sb, group, first, start - first, + priv); + if (error) + goto out_unload; + ext4_lock_group(sb, group); + } while (start <= end) { start = mb_find_next_zero_bit(bitmap, end + 1, start); if (start > end) --- a/fs/ext4/mballoc.h +++ b/fs/ext4/mballoc.h @@ -226,6 +226,7 @@ ext4_mballoc_query_range( ext4_group_t agno, ext4_grpblk_t start, ext4_grpblk_t end, + ext4_mballoc_query_range_fn meta_formatter, ext4_mballoc_query_range_fn formatter, void *priv);