From 51ff87bdd9f21a5d3672517b75d25ab5842d94a8 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Mon, 15 Oct 2007 14:42:35 +0100 Subject: [GFS2] Clean up internal read function As requested by Christoph, this patch cleans up GFS2's internal read function so that it no longer uses the do_generic_mapping_read function. This function is obsolete and GFS2 is the last user of it. As a side effect the internal read code gets smaller and easier to read and gfs2_readpage is split into two. One function has the locking and the other function has the rest of the logic. Signed-off-by: Steven Whitehouse Cc: Christoph Hellwig --- fs/gfs2/rgrp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/gfs2/rgrp.c') diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index 708c287e1d0e..09848aac45f6 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -25,10 +25,10 @@ #include "rgrp.h" #include "super.h" #include "trans.h" -#include "ops_file.h" #include "util.h" #include "log.h" #include "inode.h" +#include "ops_address.h" #define BFITNOENT ((u32)~0) #define NO_BLOCK ((u64)~0) -- cgit v1.2.2 From 292c8c14cace19c94c6abe25506310239daf949e Mon Sep 17 00:00:00 2001 From: Abhijith Das Date: Thu, 29 Nov 2007 14:13:54 -0600 Subject: [GFS2] patch to check for recursive lock requests in gfs2_rename code path A certain scenario in the rename code path triggers a kernel BUG() because it accidentally does recursive locking The first lock is requested to unlink an already existing inode (replacing a file) and the second lock is requested when the destination directory needs to alloc some space. It is rare that these two events happen during the same rename call, and even more rare that these two instances try to lock the same rgrp. It is, however, possible. https://bugzilla.redhat.com/show_bug.cgi?id=404711 Signed-off-by: Abhijith Das Signed-off-by: Steven Whitehouse --- fs/gfs2/rgrp.c | 33 +++++++++++++++++++++++++-------- 1 file changed, 25 insertions(+), 8 deletions(-) (limited to 'fs/gfs2/rgrp.c') diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index 09848aac45f6..e0ee195558d3 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -1063,22 +1063,30 @@ static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked) int flags = LM_FLAG_TRY; int skipped = 0; int loops = 0; - int error; + int error, rg_locked; /* Try recently successful rgrps */ rgd = recent_rgrp_first(sdp, ip->i_last_rg_alloc); while (rgd) { - error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, - LM_FLAG_TRY, &al->al_rgd_gh); + rg_locked = 0; + + if (gfs2_glock_is_locked_by_me(rgd->rd_gl)) { + rg_locked = 1; + error = 0; + } else { + error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, + LM_FLAG_TRY, &al->al_rgd_gh); + } switch (error) { case 0: if (try_rgrp_fit(rgd, al)) goto out; if (rgd->rd_flags & GFS2_RDF_CHECK) inode = try_rgrp_unlink(rgd, last_unlinked); - gfs2_glock_dq_uninit(&al->al_rgd_gh); + if (!rg_locked) + gfs2_glock_dq_uninit(&al->al_rgd_gh); if (inode) return inode; rgd = recent_rgrp_next(rgd, 1); @@ -1098,15 +1106,23 @@ static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked) begin = rgd = forward_rgrp_get(sdp); for (;;) { - error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, flags, - &al->al_rgd_gh); + rg_locked = 0; + + if (gfs2_glock_is_locked_by_me(rgd->rd_gl)) { + rg_locked = 1; + error = 0; + } else { + error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, flags, + &al->al_rgd_gh); + } switch (error) { case 0: if (try_rgrp_fit(rgd, al)) goto out; if (rgd->rd_flags & GFS2_RDF_CHECK) inode = try_rgrp_unlink(rgd, last_unlinked); - gfs2_glock_dq_uninit(&al->al_rgd_gh); + if (!rg_locked) + gfs2_glock_dq_uninit(&al->al_rgd_gh); if (inode) return inode; break; @@ -1213,7 +1229,8 @@ void gfs2_inplace_release(struct gfs2_inode *ip) al->al_line); al->al_rgd = NULL; - gfs2_glock_dq_uninit(&al->al_rgd_gh); + if (al->al_rgd_gh.gh_gl) + gfs2_glock_dq_uninit(&al->al_rgd_gh); if (ip != GFS2_I(sdp->sd_rindex)) gfs2_glock_dq_uninit(&al->al_ri_gh); } -- cgit v1.2.2 From 5fdc2eeb5d1d3800367f471690b01fcd1fd5b963 Mon Sep 17 00:00:00 2001 From: Bob Peterson Date: Tue, 11 Dec 2007 19:00:16 -0600 Subject: [GFS2] Run through full bitmaps quicker in gfs2_bitfit I eliminated the passing of an unused parameter into gfs2_bitfit called rgd. This also changes the gfs2_bitfit code that searches for free (or used) blocks. Before, the code was trying to check for bytes that indicated 4 blocks in the undesired state. The problem is, it was spending more time trying to do this than it actually was saving. This version only optimizes the case where we're looking for free blocks, and it checks a machine word at a time. So on 32-bit machines, it will check 32-bits (16 blocks) and on 64-bit machines, it will check 64-bits (32 blocks) at a time. The compiler optimizes that quite well and we save some time, especially when running through full bitmaps (like the bitmaps allocated for the journals). There's probably a more elegant or optimized way to do this, but I haven't thought of it yet. I'm open to suggestions. Signed-off-by: Bob Peterson Signed-off-by: Steven Whitehouse --- fs/gfs2/rgrp.c | 54 +++++++++++++++++++++++++++++------------------------- 1 file changed, 29 insertions(+), 25 deletions(-) (limited to 'fs/gfs2/rgrp.c') diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index e0ee195558d3..d7ff9cf6653f 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -126,41 +126,46 @@ static unsigned char gfs2_testbit(struct gfs2_rgrpd *rgd, unsigned char *buffer, * Return: the block number (bitmap buffer scope) that was found */ -static u32 gfs2_bitfit(struct gfs2_rgrpd *rgd, unsigned char *buffer, - unsigned int buflen, u32 goal, - unsigned char old_state) +static u32 gfs2_bitfit(unsigned char *buffer, unsigned int buflen, u32 goal, + unsigned char old_state) { - unsigned char *byte, *end, alloc; + unsigned char *byte; u32 blk = goal; - unsigned int bit; + unsigned int bit, bitlong; + unsigned long *plong, plong55; + static int c = 0; byte = buffer + (goal / GFS2_NBBY); + plong = buffer + (goal / GFS2_NBBY); bit = (goal % GFS2_NBBY) * GFS2_BIT_SIZE; - end = buffer + buflen; - alloc = (old_state == GFS2_BLKST_FREE) ? 0x55 : 0; - - while (byte < end) { - /* If we're looking for a free block we can eliminate all - bitmap settings with 0x55, which represents four data - blocks in a row. If we're looking for a data block, we can - eliminate 0x00 which corresponds to four free blocks. */ - if ((*byte & 0x55) == alloc) { - blk += (8 - bit) >> 1; - - bit = 0; - byte++; - + bitlong = bit; +#if BITS_PER_LONG == 32 + plong55 = 0x55555555; +#else + plong55 = 0x5555555555555555; +#endif + while (byte < buffer + buflen) { + + if (bitlong == 0 && old_state == 0 && *plong == plong55) { + plong++; + byte += sizeof(unsigned long); + blk += sizeof(unsigned long) * GFS2_NBBY; continue; } - - if (((*byte >> bit) & GFS2_BIT_MASK) == old_state) + if (((*byte >> bit) & GFS2_BIT_MASK) == old_state) { + c++; return blk; - + } bit += GFS2_BIT_SIZE; if (bit >= 8) { bit = 0; byte++; } + bitlong += GFS2_BIT_SIZE; + if (bitlong >= sizeof(unsigned long) * 8) { + bitlong = 0; + plong++; + } blk++; } @@ -1318,11 +1323,10 @@ static u32 rgblk_search(struct gfs2_rgrpd *rgd, u32 goal, /* The GFS2_BLKST_UNLINKED state doesn't apply to the clone bitmaps, so we must search the originals for that. */ if (old_state != GFS2_BLKST_UNLINKED && bi->bi_clone) - blk = gfs2_bitfit(rgd, bi->bi_clone + bi->bi_offset, + blk = gfs2_bitfit(bi->bi_clone + bi->bi_offset, bi->bi_len, goal, old_state); else - blk = gfs2_bitfit(rgd, - bi->bi_bh->b_data + bi->bi_offset, + blk = gfs2_bitfit(bi->bi_bh->b_data + bi->bi_offset, bi->bi_len, goal, old_state); if (blk != BFITNOENT) break; -- cgit v1.2.2 From b3513fca7e41965d85125c9770ce5f8fd4ff509a Mon Sep 17 00:00:00 2001 From: Bob Peterson Date: Wed, 12 Dec 2007 09:24:08 -0600 Subject: [GFS2] Incremental patch to fix compiler warning Signed-off-by: Bob Peterson Signed-off-by: Steven Whitehouse --- fs/gfs2/rgrp.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'fs/gfs2/rgrp.c') diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index d7ff9cf6653f..68c4bf363c46 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -133,10 +133,9 @@ static u32 gfs2_bitfit(unsigned char *buffer, unsigned int buflen, u32 goal, u32 blk = goal; unsigned int bit, bitlong; unsigned long *plong, plong55; - static int c = 0; byte = buffer + (goal / GFS2_NBBY); - plong = buffer + (goal / GFS2_NBBY); + plong = (unsigned long *)(buffer + (goal / GFS2_NBBY)); bit = (goal % GFS2_NBBY) * GFS2_BIT_SIZE; bitlong = bit; #if BITS_PER_LONG == 32 @@ -152,10 +151,8 @@ static u32 gfs2_bitfit(unsigned char *buffer, unsigned int buflen, u32 goal, blk += sizeof(unsigned long) * GFS2_NBBY; continue; } - if (((*byte >> bit) & GFS2_BIT_MASK) == old_state) { - c++; + if (((*byte >> bit) & GFS2_BIT_MASK) == old_state) return blk; - } bit += GFS2_BIT_SIZE; if (bit >= 8) { bit = 0; -- cgit v1.2.2 From 6dbd822487d0a9f14432cb4680415b80656b63a2 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Thu, 10 Jan 2008 15:18:55 +0000 Subject: [GFS2] Reduce inode size by moving i_alloc out of line It is possible to reduce the size of GFS2 inodes by taking the i_alloc structure out of the gfs2_inode. This patch allocates the i_alloc structure whenever its needed, and frees it afterward. This decreases the amount of low memory we use at the expense of requiring a memory allocation for each page or partial page that we write. A quick test with postmark shows that the overhead is not measurable and I also note that OCFS2 use the same approach. In the future I'd like to solve the problem by shrinking down the size of the members of the i_alloc structure, but for now, this reduces the immediate problem of using too much low-memory on x86 and doesn't add too much overhead. Signed-off-by: Steven Whitehouse --- fs/gfs2/rgrp.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) (limited to 'fs/gfs2/rgrp.c') diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index 68c4bf363c46..3552110b2e5f 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -819,11 +819,9 @@ void gfs2_rgrp_repolish_clones(struct gfs2_rgrpd *rgd) struct gfs2_alloc *gfs2_alloc_get(struct gfs2_inode *ip) { - struct gfs2_alloc *al = &ip->i_alloc; - - /* FIXME: Should assert that the correct locks are held here... */ - memset(al, 0, sizeof(*al)); - return al; + BUG_ON(ip->i_alloc != NULL); + ip->i_alloc = kzalloc(sizeof(struct gfs2_alloc), GFP_KERNEL); + return ip->i_alloc; } /** @@ -1061,7 +1059,7 @@ static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked) struct inode *inode = NULL; struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); struct gfs2_rgrpd *rgd, *begin = NULL; - struct gfs2_alloc *al = &ip->i_alloc; + struct gfs2_alloc *al = ip->i_alloc; int flags = LM_FLAG_TRY; int skipped = 0; int loops = 0; @@ -1176,7 +1174,7 @@ out: int gfs2_inplace_reserve_i(struct gfs2_inode *ip, char *file, unsigned int line) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); - struct gfs2_alloc *al = &ip->i_alloc; + struct gfs2_alloc *al = ip->i_alloc; struct inode *inode; int error = 0; u64 last_unlinked = NO_BLOCK; @@ -1222,7 +1220,7 @@ try_again: void gfs2_inplace_release(struct gfs2_inode *ip) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); - struct gfs2_alloc *al = &ip->i_alloc; + struct gfs2_alloc *al = ip->i_alloc; if (gfs2_assert_warn(sdp, al->al_alloced <= al->al_requested) == -1) fs_warn(sdp, "al_alloced = %u, al_requested = %u " @@ -1412,7 +1410,7 @@ static struct gfs2_rgrpd *rgblk_free(struct gfs2_sbd *sdp, u64 bstart, u64 gfs2_alloc_data(struct gfs2_inode *ip) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); - struct gfs2_alloc *al = &ip->i_alloc; + struct gfs2_alloc *al = ip->i_alloc; struct gfs2_rgrpd *rgd = al->al_rgd; u32 goal, blk; u64 block; @@ -1457,7 +1455,7 @@ u64 gfs2_alloc_data(struct gfs2_inode *ip) u64 gfs2_alloc_meta(struct gfs2_inode *ip) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); - struct gfs2_alloc *al = &ip->i_alloc; + struct gfs2_alloc *al = ip->i_alloc; struct gfs2_rgrpd *rgd = al->al_rgd; u32 goal, blk; u64 block; @@ -1503,7 +1501,7 @@ u64 gfs2_alloc_meta(struct gfs2_inode *ip) u64 gfs2_alloc_di(struct gfs2_inode *dip, u64 *generation) { struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode); - struct gfs2_alloc *al = &dip->i_alloc; + struct gfs2_alloc *al = dip->i_alloc; struct gfs2_rgrpd *rgd = al->al_rgd; u32 blk; u64 block; -- cgit v1.2.2