xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

GFS2: Reduce file fragmentation

Browse Source 
This patch reduces GFS2 file fragmentation by pre-reserving blocks. The
resulting improved on disk layout greatly speeds up operations in cases
which would have resulted in interlaced allocation of blocks previously.
A typical example of this is 10 parallel dd processes, each writing to a
file in a common dirctory.

The implementation uses an rbtree of reservations attached to each
resource group (and each inode).

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This commit is contained in:
Bob Peterson
2012-07-19 08:12:40 -04:00
committed by Steven Whitehouse
parent 294f2ad5a5
commit 8e2e004735
9 changed files with 706 additions and 90 deletions
Download Patch File Download Diff File Expand all files Collapse all files

49
fs/gfs2/incore.h
View File

@@ -84,6 +84,7 @@ struct gfs2_rgrpd {
u32 rd_data; /* num of data blocks in rgrp */
u32 rd_bitbytes; /* number of bytes in data bitmaps */
u32 rd_free;
u32 rd_reserved; /* number of blocks reserved */
u32 rd_free_clone;
u32 rd_dinodes;
u64 rd_igeneration;
@@ -96,6 +97,9 @@ struct gfs2_rgrpd {
#define GFS2_RDF_UPTODATE 0x20000000 /* rg is up to date */
#define GFS2_RDF_ERROR 0x40000000 /* error in rg */
#define GFS2_RDF_MASK 0xf0000000 /* mask for internal flags */
spinlock_t rd_rsspin; /* protects reservation related vars */
struct rb_root rd_rstree; /* multi-block reservation tree */
u32 rd_rs_cnt; /* count of current reservations */
};
enum gfs2_state_bits {
@@ -233,6 +237,38 @@ struct gfs2_holder {
unsigned long gh_ip;
};
/* Resource group multi-block reservation, in order of appearance:
Step 1. Function prepares to write, allocates a mb, sets the size hint.
Step 2. User calls inplace_reserve to target an rgrp, sets the rgrp info
Step 3. Function get_local_rgrp locks the rgrp, determines which bits to use
Step 4. Bits are assigned from the rgrp based on either the reservation
or wherever it can.
*/
struct gfs2_blkreserv {
/* components used during write (step 1): */
atomic_t rs_sizehint; /* hint of the write size */
/* components used during inplace_reserve (step 2): */
u32 rs_requested; /* Filled in by caller of gfs2_inplace_reserve() */
/* components used during get_local_rgrp (step 3): */
struct gfs2_rgrpd *rs_rgd; /* pointer to the gfs2_rgrpd */
struct gfs2_holder rs_rgd_gh; /* Filled in by get_local_rgrp */
struct rb_node rs_node; /* link to other block reservations */
/* components used during block searches and assignments (step 4): */
struct gfs2_bitmap *rs_bi; /* bitmap for the current allocation */
u32 rs_biblk; /* start block relative to the bi */
u32 rs_free; /* how many blocks are still free */
/* ancillary quota stuff */
struct gfs2_quota_data *rs_qa_qd[2 * MAXQUOTAS];
struct gfs2_holder rs_qa_qd_ghs[2 * MAXQUOTAS];
unsigned int rs_qa_qd_num;
};
enum {
GLF_LOCK = 1,
GLF_DEMOTE = 3,
@@ -290,16 +326,6 @@ struct gfs2_glock {
#define GFS2_MIN_LVB_SIZE 32 /* Min size of LVB that gfs2 supports */
struct gfs2_blkreserv {
u32 rs_requested; /* Filled in by caller of gfs2_inplace_reserve() */
struct gfs2_holder rs_rgd_gh; /* Filled in by gfs2_inplace_reserve() */
/* ancillary quota stuff */
struct gfs2_quota_data *rs_qa_qd[2 * MAXQUOTAS];
struct gfs2_holder rs_qa_qd_ghs[2 * MAXQUOTAS];
unsigned int rs_qa_qd_num;
};
enum {
GIF_INVALID = 0,
GIF_QD_LOCKED = 1,
@@ -307,7 +333,6 @@ enum {
GIF_SW_PAGED = 3,
};
struct gfs2_inode {
struct inode i_inode;
u64 i_no_addr;
@@ -318,7 +343,7 @@ struct gfs2_inode {
struct gfs2_glock *i_gl; /* Move into i_gh? */
struct gfs2_holder i_iopen_gh;
struct gfs2_holder i_gh; /* for prepare/commit_write only */
struct gfs2_blkreserv *i_res; /* resource group block reservation */
struct gfs2_blkreserv *i_res; /* rgrp multi-block reservation */
struct gfs2_rgrpd *i_rgd;
u64 i_goal; /* goal block for allocations */
struct rw_semaphore i_rw_mutex;