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linux-next/fs/gfs2/rgrp.h

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/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License version 2.
*/
#ifndef __RGRP_DOT_H__
#define __RGRP_DOT_H__
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#include <linux/uaccess.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
/* Since each block in the file system is represented by two bits in the
* bitmap, one 64-bit word in the bitmap will represent 32 blocks.
* By reserving 32 blocks at a time, we can optimize / shortcut how we search
* through the bitmaps by looking a word at a time.
*/
#define RGRP_RSRV_MINBLKS 32
#define RGRP_RSRV_ADDBLKS 64
struct gfs2_rgrpd;
struct gfs2_sbd;
struct gfs2_holder;
extern void gfs2_rgrp_verify(struct gfs2_rgrpd *rgd);
extern struct gfs2_rgrpd *gfs2_blk2rgrpd(struct gfs2_sbd *sdp, u64 blk, bool exact);
extern struct gfs2_rgrpd *gfs2_rgrpd_get_first(struct gfs2_sbd *sdp);
extern struct gfs2_rgrpd *gfs2_rgrpd_get_next(struct gfs2_rgrpd *rgd);
extern void gfs2_clear_rgrpd(struct gfs2_sbd *sdp);
extern int gfs2_rindex_update(struct gfs2_sbd *sdp);
extern void gfs2_free_clones(struct gfs2_rgrpd *rgd);
GFS2: Use rbtree for resource groups and clean up bitmap buffer ref count scheme Here is an update of Bob's original rbtree patch which, in addition, also resolves the rather strange ref counting that was being done relating to the bitmap blocks. Originally we had a dual system for journaling resource groups. The metadata blocks were journaled and also the rgrp itself was added to a list. The reason for adding the rgrp to the list in the journal was so that the "repolish clones" code could be run to update the free space, and potentially send any discard requests when the log was flushed. This was done by comparing the "cloned" bitmap with what had been written back on disk during the transaction commit. Due to this, there was a requirement to hang on to the rgrps' bitmap buffers until the journal had been flushed. For that reason, there was a rather complicated set up in the ->go_lock ->go_unlock functions for rgrps involving both a mutex and a spinlock (the ->sd_rindex_spin) to maintain a reference count on the buffers. However, the journal maintains a reference count on the buffers anyway, since they are being journaled as metadata buffers. So by moving the code which deals with the post-journal accounting for bitmap blocks to the metadata journaling code, we can entirely dispense with the rather strange buffer ref counting scheme and also the requirement to journal the rgrps. The net result of all this is that the ->sd_rindex_spin is left to do exactly one job, and that is to look after the rbtree or rgrps. This patch is designed to be a stepping stone towards using RCU for the rbtree of resource groups, however the reduction in the number of uses of the ->sd_rindex_spin is likely to have benefits for multi-threaded workloads, anyway. The patch retains ->go_lock and ->go_unlock for rgrps, however these maybe also be removed in future in favour of calling the functions directly where required in the code. That will allow locking of resource groups without needing to actually read them in - something that could be useful in speeding up statfs. In the mean time though it is valid to dereference ->bi_bh only when the rgrp is locked. This is basically the same rule as before, modulo the references not being valid until the following journal flush. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com> Cc: Benjamin Marzinski <bmarzins@redhat.com>
2011-08-31 16:53:19 +08:00
extern int gfs2_rgrp_go_lock(struct gfs2_holder *gh);
extern void gfs2_rgrp_brelse(struct gfs2_rgrpd *rgd);
GFS2: Use rbtree for resource groups and clean up bitmap buffer ref count scheme Here is an update of Bob's original rbtree patch which, in addition, also resolves the rather strange ref counting that was being done relating to the bitmap blocks. Originally we had a dual system for journaling resource groups. The metadata blocks were journaled and also the rgrp itself was added to a list. The reason for adding the rgrp to the list in the journal was so that the "repolish clones" code could be run to update the free space, and potentially send any discard requests when the log was flushed. This was done by comparing the "cloned" bitmap with what had been written back on disk during the transaction commit. Due to this, there was a requirement to hang on to the rgrps' bitmap buffers until the journal had been flushed. For that reason, there was a rather complicated set up in the ->go_lock ->go_unlock functions for rgrps involving both a mutex and a spinlock (the ->sd_rindex_spin) to maintain a reference count on the buffers. However, the journal maintains a reference count on the buffers anyway, since they are being journaled as metadata buffers. So by moving the code which deals with the post-journal accounting for bitmap blocks to the metadata journaling code, we can entirely dispense with the rather strange buffer ref counting scheme and also the requirement to journal the rgrps. The net result of all this is that the ->sd_rindex_spin is left to do exactly one job, and that is to look after the rbtree or rgrps. This patch is designed to be a stepping stone towards using RCU for the rbtree of resource groups, however the reduction in the number of uses of the ->sd_rindex_spin is likely to have benefits for multi-threaded workloads, anyway. The patch retains ->go_lock and ->go_unlock for rgrps, however these maybe also be removed in future in favour of calling the functions directly where required in the code. That will allow locking of resource groups without needing to actually read them in - something that could be useful in speeding up statfs. In the mean time though it is valid to dereference ->bi_bh only when the rgrp is locked. This is basically the same rule as before, modulo the references not being valid until the following journal flush. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com> Cc: Benjamin Marzinski <bmarzins@redhat.com>
2011-08-31 16:53:19 +08:00
extern void gfs2_rgrp_go_unlock(struct gfs2_holder *gh);
extern struct gfs2_alloc *gfs2_alloc_get(struct gfs2_inode *ip);
#define GFS2_AF_ORLOV 1
extern int gfs2_inplace_reserve(struct gfs2_inode *ip,
struct gfs2_alloc_parms *ap);
extern void gfs2_inplace_release(struct gfs2_inode *ip);
extern int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *n,
bool dinode, u64 *generation);
extern int gfs2_rsqa_alloc(struct gfs2_inode *ip);
extern void gfs2_rs_deltree(struct gfs2_blkreserv *rs);
extern void gfs2_rsqa_delete(struct gfs2_inode *ip, atomic_t *wcount);
extern void __gfs2_free_blocks(struct gfs2_inode *ip, struct gfs2_rgrpd *rgd,
u64 bstart, u32 blen, int meta);
extern void gfs2_free_meta(struct gfs2_inode *ip, struct gfs2_rgrpd *rgd,
u64 bstart, u32 blen);
extern void gfs2_free_di(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip);
extern void gfs2_unlink_di(struct inode *inode);
extern int gfs2_check_blk_type(struct gfs2_sbd *sdp, u64 no_addr,
unsigned int type);
struct gfs2_rgrp_list {
unsigned int rl_rgrps;
unsigned int rl_space;
struct gfs2_rgrpd **rl_rgd;
struct gfs2_holder *rl_ghs;
};
extern void gfs2_rlist_add(struct gfs2_inode *ip, struct gfs2_rgrp_list *rlist,
u64 block);
extern void gfs2_rlist_alloc(struct gfs2_rgrp_list *rlist);
extern void gfs2_rlist_free(struct gfs2_rgrp_list *rlist);
extern u64 gfs2_ri_total(struct gfs2_sbd *sdp);
extern void gfs2_rgrp_dump(struct seq_file *seq, struct gfs2_glock *gl);
extern int gfs2_rgrp_send_discards(struct gfs2_sbd *sdp, u64 offset,
struct buffer_head *bh,
const struct gfs2_bitmap *bi, unsigned minlen, u64 *ptrimmed);
extern int gfs2_fitrim(struct file *filp, void __user *argp);
/* This is how to tell if a reservation is in the rgrp tree: */
static inline bool gfs2_rs_active(const struct gfs2_blkreserv *rs)
{
return rs && !RB_EMPTY_NODE(&rs->rs_node);
}
GFS2: Non-recursive delete Implement truncate/delete as a non-recursive algorithm. The older algorithm was implemented with recursion to strip off each layer at a time (going by height, starting with the maximum height. This version tries to do the same thing but without recursion, and without needing to allocate new structures or lists in memory. For example, say you want to truncate a very large file to 1 byte, and its end-of-file metapath is: 0.505.463.428. The starting metapath would be 0.0.0.0. Since it's a truncate to non-zero, it needs to preserve that byte, and all metadata pointing to it. So it would start at 0.0.0.0, look up all its metadata buffers, then free all data blocks pointed to at the highest level. After that buffer is "swept", it moves on to 0.0.0.1, then 0.0.0.2, etc., reading in buffers and sweeping them clean. When it gets to the end of the 0.0.0 metadata buffer (for 4K blocks the last valid one is 0.0.0.508), it backs up to the previous height and starts working on 0.0.1.0, then 0.0.1.1, and so forth. After it reaches the end and sweeps 0.0.1.508, it continues with 0.0.2.0, and so on. When that height is exhausted, and it reaches 0.0.508.508 it backs up another level, to 0.1.0.0, then 0.1.0.1, through 0.1.0.508. So it has to keep marching backwards and forwards through the metadata until it's all swept clean. Once it has all the data blocks freed, it lowers the strip height, and begins the process all over again, but with one less height. This time it sweeps 0.0.0 through 0.505.463. When that's clean, it lowers the strip height again and works to free 0.505. Eventually it strips the lowest height, 0. For a delete or truncate to 0, all metadata for all heights of 0.0.0.0 would be freed. For a truncate to 1 byte, 0.0.0.0 would be preserved. This isn't much different from normal integer incrementing, where an integer gets incremented from 0000 (0.0.0.0) to 3021 (3.0.2.1). So 0000 gets increments to 0001, 0002, up to 0009, then on to 0010, 0011 up to 0099, then 0100 and so forth. It's just that each "digit" goes from 0 to 508 (for a total of 509 pointers) rather than from 0 to 9. Note that the dinode will only have 483 pointers due to the dinode structure itself. Also note: this is just an example. These numbers (509 and 483) are based on a standard 4K block size. Smaller block sizes will yield smaller numbers of indirect pointers accordingly. The truncation process is accomplished with the help of two major functions and a few helper functions. Functions do_strip and recursive_scan are obsolete, so removed. New function sweep_bh_for_rgrps cleans a buffer_head pointed to by the given metapath and height. By cleaning, I mean it frees all blocks starting at the offset passed in metapath. It starts at the first block in the buffer pointed to by the metapath and identifies its resource group (rgrp). From there it frees all subsequent block pointers that lie within that rgrp. If it's already inside a transaction, it stays within it as long as it can. In other words, it doesn't close a transaction until it knows it's freed what it can from the resource group. In this way, multiple buffers may be cleaned in a single transaction, as long as those blocks in the buffer all lie within the same rgrp. If it's not in a transaction, it starts one. If the buffer_head has references to blocks within multiple rgrps, it frees all the blocks inside the first rgrp it finds, then closes the transaction. Then it repeats the cycle: identifies the next unfreed block, uses it to find its rgrp, then starts a new transaction for that set. It repeats this process repeatedly until the buffer_head contains no more references to any blocks past the given metapath. Function trunc_dealloc has been reworked into a finite state automaton. It has basically 3 active states: DEALLOC_MP_FULL, DEALLOC_MP_LOWER, and DEALLOC_FILL_MP: The DEALLOC_MP_FULL state implies the metapath has a full set of buffers out to the "shrink height", and therefore, it can call function sweep_bh_for_rgrps to free the blocks within the highest height of the metapath. If it's just swept the lowest level (or an error has occurred) the state machine is ended. Otherwise it proceeds to the DEALLOC_MP_LOWER state. The DEALLOC_MP_LOWER state implies we are finished with a given buffer_head, which may now be released, and therefore we are then missing some buffer information from the metapath. So we need to find more buffers to read in. In most cases, this is just a matter of releasing the buffer_head and moving to the next pointer from the previous height, so it may be read in and swept as well. If it can't find another non-null pointer to process, it checks whether it's reached the end of a height and needs to lower the strip height, or whether it still needs move forward through the previous height's metadata. In this state, all zero-pointers are skipped. From this state, it can only loop around (once more backing up another height) or, once a valid metapath is found (one that has non-zero pointers), proceed to state DEALLOC_FILL_MP. The DEALLOC_FILL_MP state implies that we have a metapath but not all its buffers are read in. So we must proceed to read in buffer_heads until the metapath has a valid buffer for every height. If the previous state backed us up 3 heights, we may need to read in a buffer, increment the height, then repeat the process until buffers have been read in for all required heights. If it's successful reading a buffer, and it's at the highest height we need, it proceeds back to the DEALLOC_MP_FULL state. If it's unable to fill in a buffer, (encounters a hole, etc.) it tries to find another non-zero block pointer. If they're all zero, it lowers the height and returns to the DEALLOC_MP_LOWER state. If it finds a good non-null pointer, it loops around and reads it in, while keeping the metapath in lock-step with the pointers it examines. The state machine runs until the truncation request is satisfied. Then any transactions are ended, the quota and statfs data are updated, and the function is complete. Helper function metaptr1 was introduced to be an easy way to determine the start of a buffer_head's indirect pointers. Helper function lookup_mp_height was introduced to find a metapath index and read in the buffer that corresponds to it. In this way, function lookup_metapath becomes a simple loop to call it for every height. Helper function fillup_metapath is similar to lookup_metapath except it can do partial lookups. If the state machine backed up multiple levels (like 2999 wrapping to 3000) it needs to find out the next starting point and start issuing metadata reads at that point. Helper function hptrs is a shortcut to determine how many pointers should be expected in a buffer. Height 0 is the dinode which has fewer pointers than the others. Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2017-02-06 21:28:32 +08:00
static inline int rgrp_contains_block(struct gfs2_rgrpd *rgd, u64 block)
{
u64 first = rgd->rd_data0;
u64 last = first + rgd->rd_data;
return first <= block && block < last;
}
extern void check_and_update_goal(struct gfs2_inode *ip);
#endif /* __RGRP_DOT_H__ */