diff options
author | Chris Mason <clm@fb.com> | 2016-01-11 05:59:32 -0800 |
---|---|---|
committer | Chris Mason <clm@fb.com> | 2016-01-11 05:59:32 -0800 |
commit | a3058101c17d2825f34a0ab5c37d93ead0f4d9dc (patch) | |
tree | 193417b02c4fa79b582b435e154761b91a501884 /fs/btrfs/super.c | |
parent | 511711af91f21d80b27f18b569352d6896562828 (diff) | |
parent | ee592d07716139ef7c3ea8049936cbc3aafbc533 (diff) | |
download | op-kernel-dev-a3058101c17d2825f34a0ab5c37d93ead0f4d9dc.zip op-kernel-dev-a3058101c17d2825f34a0ab5c37d93ead0f4d9dc.tar.gz |
Merge branch 'misc-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5
Diffstat (limited to 'fs/btrfs/super.c')
-rw-r--r-- | fs/btrfs/super.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 9153d54..ff15087 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -310,7 +310,7 @@ enum { Opt_err, }; -static match_table_t tokens = { +static const match_table_t tokens = { {Opt_degraded, "degraded"}, {Opt_subvol, "subvol=%s"}, {Opt_subvolid, "subvolid=%s"}, @@ -1991,6 +1991,8 @@ static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes) * there are other factors that may change the result (like a new metadata * chunk). * + * If metadata is exhausted, f_bavail will be 0. + * * FIXME: not accurate for mixed block groups, total and free/used are ok, * available appears slightly larger. */ @@ -2002,11 +2004,13 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) struct btrfs_space_info *found; u64 total_used = 0; u64 total_free_data = 0; + u64 total_free_meta = 0; int bits = dentry->d_sb->s_blocksize_bits; __be32 *fsid = (__be32 *)fs_info->fsid; unsigned factor = 1; struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; int ret; + u64 thresh = 0; /* * holding chunk_muext to avoid allocating new chunks, holding @@ -2032,6 +2036,8 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) } } } + if (found->flags & BTRFS_BLOCK_GROUP_METADATA) + total_free_meta += found->disk_total - found->disk_used; total_used += found->disk_used; } @@ -2054,6 +2060,24 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) buf->f_bavail += div_u64(total_free_data, factor); buf->f_bavail = buf->f_bavail >> bits; + /* + * We calculate the remaining metadata space minus global reserve. If + * this is (supposedly) smaller than zero, there's no space. But this + * does not hold in practice, the exhausted state happens where's still + * some positive delta. So we apply some guesswork and compare the + * delta to a 4M threshold. (Practically observed delta was ~2M.) + * + * We probably cannot calculate the exact threshold value because this + * depends on the internal reservations requested by various + * operations, so some operations that consume a few metadata will + * succeed even if the Avail is zero. But this is better than the other + * way around. + */ + thresh = 4 * 1024 * 1024; + + if (total_free_meta - thresh < block_rsv->size) + buf->f_bavail = 0; + buf->f_type = BTRFS_SUPER_MAGIC; buf->f_bsize = dentry->d_sb->s_blocksize; buf->f_namelen = BTRFS_NAME_LEN; |