diff options
Diffstat (limited to 'fs/nilfs2/sufile.c')
| -rw-r--r-- | fs/nilfs2/sufile.c | 558 |
1 files changed, 558 insertions, 0 deletions
diff --git a/fs/nilfs2/sufile.c b/fs/nilfs2/sufile.c new file mode 100644 index 00000000000..98e68677f04 --- /dev/null +++ b/fs/nilfs2/sufile.c @@ -0,0 +1,558 @@ +/* + * sufile.c - NILFS segment usage file. + * + * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + * Written by Koji Sato <koji@osrg.net>. + */ + +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/string.h> +#include <linux/buffer_head.h> +#include <linux/errno.h> +#include <linux/nilfs2_fs.h> +#include "mdt.h" +#include "sufile.h" + + +static inline unsigned long +nilfs_sufile_segment_usages_per_block(const struct inode *sufile) +{ + return NILFS_MDT(sufile)->mi_entries_per_block; +} + +static unsigned long +nilfs_sufile_get_blkoff(const struct inode *sufile, __u64 segnum) +{ + __u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset; + do_div(t, nilfs_sufile_segment_usages_per_block(sufile)); + return (unsigned long)t; +} + +static unsigned long +nilfs_sufile_get_offset(const struct inode *sufile, __u64 segnum) +{ + __u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset; + return do_div(t, nilfs_sufile_segment_usages_per_block(sufile)); +} + +static unsigned long +nilfs_sufile_segment_usages_in_block(const struct inode *sufile, __u64 curr, + __u64 max) +{ + return min_t(unsigned long, + nilfs_sufile_segment_usages_per_block(sufile) - + nilfs_sufile_get_offset(sufile, curr), + max - curr + 1); +} + +static inline struct nilfs_sufile_header * +nilfs_sufile_block_get_header(const struct inode *sufile, + struct buffer_head *bh, + void *kaddr) +{ + return kaddr + bh_offset(bh); +} + +static struct nilfs_segment_usage * +nilfs_sufile_block_get_segment_usage(const struct inode *sufile, __u64 segnum, + struct buffer_head *bh, void *kaddr) +{ + return kaddr + bh_offset(bh) + + nilfs_sufile_get_offset(sufile, segnum) * + NILFS_MDT(sufile)->mi_entry_size; +} + +static inline int nilfs_sufile_get_header_block(struct inode *sufile, + struct buffer_head **bhp) +{ + return nilfs_mdt_get_block(sufile, 0, 0, NULL, bhp); +} + +static inline int +nilfs_sufile_get_segment_usage_block(struct inode *sufile, __u64 segnum, + int create, struct buffer_head **bhp) +{ + return nilfs_mdt_get_block(sufile, + nilfs_sufile_get_blkoff(sufile, segnum), + create, NULL, bhp); +} + +static void nilfs_sufile_mod_counter(struct buffer_head *header_bh, + u64 ncleanadd, u64 ndirtyadd) +{ + struct nilfs_sufile_header *header; + void *kaddr; + + kaddr = kmap_atomic(header_bh->b_page, KM_USER0); + header = kaddr + bh_offset(header_bh); + le64_add_cpu(&header->sh_ncleansegs, ncleanadd); + le64_add_cpu(&header->sh_ndirtysegs, ndirtyadd); + kunmap_atomic(kaddr, KM_USER0); + + nilfs_mdt_mark_buffer_dirty(header_bh); +} + +int nilfs_sufile_update(struct inode *sufile, __u64 segnum, int create, + void (*dofunc)(struct inode *, __u64, + struct buffer_head *, + struct buffer_head *)) +{ + struct buffer_head *header_bh, *bh; + int ret; + + if (unlikely(segnum >= nilfs_sufile_get_nsegments(sufile))) { + printk(KERN_WARNING "%s: invalid segment number: %llu\n", + __func__, (unsigned long long)segnum); + return -EINVAL; + } + down_write(&NILFS_MDT(sufile)->mi_sem); + + ret = nilfs_sufile_get_header_block(sufile, &header_bh); + if (ret < 0) + goto out_sem; + + ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, create, &bh); + if (!ret) { + dofunc(sufile, segnum, header_bh, bh); + brelse(bh); + } + brelse(header_bh); + + out_sem: + up_write(&NILFS_MDT(sufile)->mi_sem); + return ret; +} + +/** + * nilfs_sufile_alloc - allocate a segment + * @sufile: inode of segment usage file + * @segnump: pointer to segment number + * + * Description: nilfs_sufile_alloc() allocates a clean segment. + * + * Return Value: On success, 0 is returned and the segment number of the + * allocated segment is stored in the place pointed by @segnump. On error, one + * of the following negative error codes is returned. + * + * %-EIO - I/O error. + * + * %-ENOMEM - Insufficient amount of memory available. + * + * %-ENOSPC - No clean segment left. + */ +int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump) +{ + struct buffer_head *header_bh, *su_bh; + struct nilfs_sufile_header *header; + struct nilfs_segment_usage *su; + size_t susz = NILFS_MDT(sufile)->mi_entry_size; + __u64 segnum, maxsegnum, last_alloc; + void *kaddr; + unsigned long nsegments, ncleansegs, nsus; + int ret, i, j; + + down_write(&NILFS_MDT(sufile)->mi_sem); + + ret = nilfs_sufile_get_header_block(sufile, &header_bh); + if (ret < 0) + goto out_sem; + kaddr = kmap_atomic(header_bh->b_page, KM_USER0); + header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr); + ncleansegs = le64_to_cpu(header->sh_ncleansegs); + last_alloc = le64_to_cpu(header->sh_last_alloc); + kunmap_atomic(kaddr, KM_USER0); + + nsegments = nilfs_sufile_get_nsegments(sufile); + segnum = last_alloc + 1; + maxsegnum = nsegments - 1; + for (i = 0; i < nsegments; i += nsus) { + if (segnum >= nsegments) { + /* wrap around */ + segnum = 0; + maxsegnum = last_alloc; + } + ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1, + &su_bh); + if (ret < 0) + goto out_header; + kaddr = kmap_atomic(su_bh->b_page, KM_USER0); + su = nilfs_sufile_block_get_segment_usage( + sufile, segnum, su_bh, kaddr); + + nsus = nilfs_sufile_segment_usages_in_block( + sufile, segnum, maxsegnum); + for (j = 0; j < nsus; j++, su = (void *)su + susz, segnum++) { + if (!nilfs_segment_usage_clean(su)) + continue; + /* found a clean segment */ + nilfs_segment_usage_set_dirty(su); + kunmap_atomic(kaddr, KM_USER0); + + kaddr = kmap_atomic(header_bh->b_page, KM_USER0); + header = nilfs_sufile_block_get_header( + sufile, header_bh, kaddr); + le64_add_cpu(&header->sh_ncleansegs, -1); + le64_add_cpu(&header->sh_ndirtysegs, 1); + header->sh_last_alloc = cpu_to_le64(segnum); + kunmap_atomic(kaddr, KM_USER0); + + nilfs_mdt_mark_buffer_dirty(header_bh); + nilfs_mdt_mark_buffer_dirty(su_bh); + nilfs_mdt_mark_dirty(sufile); + brelse(su_bh); + *segnump = segnum; + goto out_header; + } + + kunmap_atomic(kaddr, KM_USER0); + brelse(su_bh); + } + + /* no segments left */ + ret = -ENOSPC; + + out_header: + brelse(header_bh); + + out_sem: + up_write(&NILFS_MDT(sufile)->mi_sem); + return ret; +} + +void nilfs_sufile_do_cancel_free(struct inode *sufile, __u64 segnum, + struct buffer_head *header_bh, + struct buffer_head *su_bh) +{ + struct nilfs_segment_usage *su; + void *kaddr; + + kaddr = kmap_atomic(su_bh->b_page, KM_USER0); + su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr); + if (unlikely(!nilfs_segment_usage_clean(su))) { + printk(KERN_WARNING "%s: segment %llu must be clean\n", + __func__, (unsigned long long)segnum); + kunmap_atomic(kaddr, KM_USER0); + return; + } + nilfs_segment_usage_set_dirty(su); + kunmap_atomic(kaddr, KM_USER0); + + nilfs_sufile_mod_counter(header_bh, -1, 1); + nilfs_mdt_mark_buffer_dirty(su_bh); + nilfs_mdt_mark_dirty(sufile); +} + +void nilfs_sufile_do_scrap(struct inode *sufile, __u64 segnum, + struct buffer_head *header_bh, + struct buffer_head *su_bh) +{ + struct nilfs_segment_usage *su; + void *kaddr; + int clean, dirty; + + kaddr = kmap_atomic(su_bh->b_page, KM_USER0); + su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr); + if (su->su_flags == cpu_to_le32(1UL << NILFS_SEGMENT_USAGE_DIRTY) && + su->su_nblocks == cpu_to_le32(0)) { + kunmap_atomic(kaddr, KM_USER0); + return; + } + clean = nilfs_segment_usage_clean(su); + dirty = nilfs_segment_usage_dirty(su); + + /* make the segment garbage */ + su->su_lastmod = cpu_to_le64(0); + su->su_nblocks = cpu_to_le32(0); + su->su_flags = cpu_to_le32(1UL << NILFS_SEGMENT_USAGE_DIRTY); + kunmap_atomic(kaddr, KM_USER0); + + nilfs_sufile_mod_counter(header_bh, clean ? (u64)-1 : 0, dirty ? 0 : 1); + nilfs_mdt_mark_buffer_dirty(su_bh); + nilfs_mdt_mark_dirty(sufile); +} + +void nilfs_sufile_do_free(struct inode *sufile, __u64 segnum, + struct buffer_head *header_bh, + struct buffer_head *su_bh) +{ + struct nilfs_segment_usage *su; + void *kaddr; + int sudirty; + + kaddr = kmap_atomic(su_bh->b_page, KM_USER0); + su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr); + if (nilfs_segment_usage_clean(su)) { + printk(KERN_WARNING "%s: segment %llu is already clean\n", + __func__, (unsigned long long)segnum); + kunmap_atomic(kaddr, KM_USER0); + return; + } + WARN_ON(nilfs_segment_usage_error(su)); + WARN_ON(!nilfs_segment_usage_dirty(su)); + + sudirty = nilfs_segment_usage_dirty(su); + nilfs_segment_usage_set_clean(su); + kunmap_atomic(kaddr, KM_USER0); + nilfs_mdt_mark_buffer_dirty(su_bh); + + nilfs_sufile_mod_counter(header_bh, 1, sudirty ? (u64)-1 : 0); + nilfs_mdt_mark_dirty(sufile); +} + +/** + * nilfs_sufile_get_segment_usage - get a segment usage + * @sufile: inode of segment usage file + * @segnum: segment number + * @sup: pointer to segment usage + * @bhp: pointer to buffer head + * + * Description: nilfs_sufile_get_segment_usage() acquires the segment usage + * specified by @segnum. + * + * Return Value: On success, 0 is returned, and the segment usage and the + * buffer head of the buffer on which the segment usage is located are stored + * in the place pointed by @sup and @bhp, respectively. On error, one of the + * following negative error codes is returned. + * + * %-EIO - I/O error. + * + * %-ENOMEM - Insufficient amount of memory available. + * + * %-EINVAL - Invalid segment usage number. + */ +int nilfs_sufile_get_segment_usage(struct inode *sufile, __u64 segnum, + struct nilfs_segment_usage **sup, + struct buffer_head **bhp) +{ + struct buffer_head *bh; + struct nilfs_segment_usage *su; + void *kaddr; + int ret; + + /* segnum is 0 origin */ + if (segnum >= nilfs_sufile_get_nsegments(sufile)) + return -EINVAL; + down_write(&NILFS_MDT(sufile)->mi_sem); + ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1, &bh); + if (ret < 0) + goto out_sem; + kaddr = kmap(bh->b_page); + su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr); + if (nilfs_segment_usage_error(su)) { + kunmap(bh->b_page); + brelse(bh); + ret = -EINVAL; + goto out_sem; + } + + if (sup != NULL) + *sup = su; + *bhp = bh; + + out_sem: + up_write(&NILFS_MDT(sufile)->mi_sem); + return ret; +} + +/** + * nilfs_sufile_put_segment_usage - put a segment usage + * @sufile: inode of segment usage file + * @segnum: segment number + * @bh: buffer head + * + * Description: nilfs_sufile_put_segment_usage() releases the segment usage + * specified by @segnum. @bh must be the buffer head which have been returned + * by a previous call to nilfs_sufile_get_segment_usage() with @segnum. + */ +void nilfs_sufile_put_segment_usage(struct inode *sufile, __u64 segnum, + struct buffer_head *bh) +{ + kunmap(bh->b_page); + brelse(bh); +} + +/** + * nilfs_sufile_get_stat - get segment usage statistics + * @sufile: inode of segment usage file + * @stat: pointer to a structure of segment usage statistics + * + * Description: nilfs_sufile_get_stat() returns information about segment + * usage. + * + * Return Value: On success, 0 is returned, and segment usage information is + * stored in the place pointed by @stat. On error, one of the following + * negative error codes is returned. + * + * %-EIO - I/O error. + * + * %-ENOMEM - Insufficient amount of memory available. + */ +int nilfs_sufile_get_stat(struct inode *sufile, struct nilfs_sustat *sustat) +{ + struct buffer_head *header_bh; + struct nilfs_sufile_header *header; + struct the_nilfs *nilfs = NILFS_MDT(sufile)->mi_nilfs; + void *kaddr; + int ret; + + down_read(&NILFS_MDT(sufile)->mi_sem); + + ret = nilfs_sufile_get_header_block(sufile, &header_bh); + if (ret < 0) + goto out_sem; + + kaddr = kmap_atomic(header_bh->b_page, KM_USER0); + header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr); + sustat->ss_nsegs = nilfs_sufile_get_nsegments(sufile); + sustat->ss_ncleansegs = le64_to_cpu(header->sh_ncleansegs); + sustat->ss_ndirtysegs = le64_to_cpu(header->sh_ndirtysegs); + sustat->ss_ctime = nilfs->ns_ctime; + sustat->ss_nongc_ctime = nilfs->ns_nongc_ctime; + spin_lock(&nilfs->ns_last_segment_lock); + sustat->ss_prot_seq = nilfs->ns_prot_seq; + spin_unlock(&nilfs->ns_last_segment_lock); + kunmap_atomic(kaddr, KM_USER0); + brelse(header_bh); + + out_sem: + up_read(&NILFS_MDT(sufile)->mi_sem); + return ret; +} + +/** + * nilfs_sufile_get_ncleansegs - get the number of clean segments + * @sufile: inode of segment usage file + * @nsegsp: pointer to the number of clean segments + * + * Description: nilfs_sufile_get_ncleansegs() acquires the number of clean + * segments. + * + * Return Value: On success, 0 is returned and the number of clean segments is + * stored in the place pointed by @nsegsp. On error, one of the following + * negative error codes is returned. + * + * %-EIO - I/O error. + * + * %-ENOMEM - Insufficient amount of memory available. + */ +int nilfs_sufile_get_ncleansegs(struct inode *sufile, unsigned long *nsegsp) +{ + struct nilfs_sustat sustat; + int ret; + + ret = nilfs_sufile_get_stat(sufile, &sustat); + if (ret == 0) + *nsegsp = sustat.ss_ncleansegs; + return ret; +} + +void nilfs_sufile_do_set_error(struct inode *sufile, __u64 segnum, + struct buffer_head *header_bh, + struct buffer_head *su_bh) +{ + struct nilfs_segment_usage *su; + void *kaddr; + int suclean; + + kaddr = kmap_atomic(su_bh->b_page, KM_USER0); + su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr); + if (nilfs_segment_usage_error(su)) { + kunmap_atomic(kaddr, KM_USER0); + return; + } + suclean = nilfs_segment_usage_clean(su); + nilfs_segment_usage_set_error(su); + kunmap_atomic(kaddr, KM_USER0); + + if (suclean) + nilfs_sufile_mod_counter(header_bh, -1, 0); + nilfs_mdt_mark_buffer_dirty(su_bh); + nilfs_mdt_mark_dirty(sufile); +} + +/** + * nilfs_sufile_get_suinfo - + * @sufile: inode of segment usage file + * @segnum: segment number to start looking + * @si: array of suinfo + * @nsi: size of suinfo array + * + * Description: + * + * Return Value: On success, 0 is returned and .... On error, one of the + * following negative error codes is returned. + * + * %-EIO - I/O error. + * + * %-ENOMEM - Insufficient amount of memory available. + */ +ssize_t nilfs_sufile_get_suinfo(struct inode *sufile, __u64 segnum, + struct nilfs_suinfo *si, size_t nsi) +{ + struct buffer_head *su_bh; + struct nilfs_segment_usage *su; + size_t susz = NILFS_MDT(sufile)->mi_entry_size; + struct the_nilfs *nilfs = NILFS_MDT(sufile)->mi_nilfs; + void *kaddr; + unsigned long nsegs, segusages_per_block; + ssize_t n; + int ret, i, j; + + down_read(&NILFS_MDT(sufile)->mi_sem); + + segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile); + nsegs = min_t(unsigned long, + nilfs_sufile_get_nsegments(sufile) - segnum, + nsi); + for (i = 0; i < nsegs; i += n, segnum += n) { + n = min_t(unsigned long, + segusages_per_block - + nilfs_sufile_get_offset(sufile, segnum), + nsegs - i); + ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, + &su_bh); + if (ret < 0) { + if (ret != -ENOENT) + goto out; + /* hole */ + memset(&si[i], 0, sizeof(struct nilfs_suinfo) * n); + continue; + } + + kaddr = kmap_atomic(su_bh->b_page, KM_USER0); + su = nilfs_sufile_block_get_segment_usage( + sufile, segnum, su_bh, kaddr); + for (j = 0; j < n; j++, su = (void *)su + susz) { + si[i + j].sui_lastmod = le64_to_cpu(su->su_lastmod); + si[i + j].sui_nblocks = le32_to_cpu(su->su_nblocks); + si[i + j].sui_flags = le32_to_cpu(su->su_flags) & + ~(1UL << NILFS_SEGMENT_USAGE_ACTIVE); + if (nilfs_segment_is_active(nilfs, segnum + j)) + si[i + j].sui_flags |= + (1UL << NILFS_SEGMENT_USAGE_ACTIVE); + } + kunmap_atomic(kaddr, KM_USER0); + brelse(su_bh); + } + ret = nsegs; + + out: + up_read(&NILFS_MDT(sufile)->mi_sem); + return ret; +} |