diff options
Diffstat (limited to 'fs/gfs2/unlinked.c')
-rw-r--r-- | fs/gfs2/unlinked.c | 453 |
1 files changed, 453 insertions, 0 deletions
diff --git a/fs/gfs2/unlinked.c b/fs/gfs2/unlinked.c new file mode 100644 index 000000000000..4a993af58c1a --- /dev/null +++ b/fs/gfs2/unlinked.c @@ -0,0 +1,453 @@ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2005 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 v.2. + */ + +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/buffer_head.h> +#include <linux/kthread.h> +#include <asm/semaphore.h> + +#include "gfs2.h" +#include "bmap.h" +#include "inode.h" +#include "meta_io.h" +#include "trans.h" +#include "unlinked.h" + +static int munge_ondisk(struct gfs2_sbd *sdp, unsigned int slot, + struct gfs2_unlinked_tag *ut) +{ + struct gfs2_inode *ip = sdp->sd_ut_inode; + unsigned int block, offset; + uint64_t dblock; + int new = 0; + struct buffer_head *bh; + int error; + + block = slot / sdp->sd_ut_per_block; + offset = slot % sdp->sd_ut_per_block; + + error = gfs2_block_map(ip, block, &new, &dblock, NULL); + if (error) + return error; + error = gfs2_meta_read(ip->i_gl, dblock, DIO_START | DIO_WAIT, &bh); + if (error) + return error; + if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_UT)) { + error = -EIO; + goto out; + } + + down(&sdp->sd_unlinked_mutex); + gfs2_trans_add_bh(ip->i_gl, bh); + gfs2_unlinked_tag_out(ut, bh->b_data + + sizeof(struct gfs2_meta_header) + + offset * sizeof(struct gfs2_unlinked_tag)); + up(&sdp->sd_unlinked_mutex); + + out: + brelse(bh); + + return error; +} + +static void ul_hash(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul) +{ + spin_lock(&sdp->sd_unlinked_spin); + list_add(&ul->ul_list, &sdp->sd_unlinked_list); + gfs2_assert(sdp, ul->ul_count); + ul->ul_count++; + atomic_inc(&sdp->sd_unlinked_count); + spin_unlock(&sdp->sd_unlinked_spin); +} + +static void ul_unhash(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul) +{ + spin_lock(&sdp->sd_unlinked_spin); + list_del_init(&ul->ul_list); + gfs2_assert(sdp, ul->ul_count > 1); + ul->ul_count--; + gfs2_assert_warn(sdp, atomic_read(&sdp->sd_unlinked_count) > 0); + atomic_dec(&sdp->sd_unlinked_count); + spin_unlock(&sdp->sd_unlinked_spin); +} + +static struct gfs2_unlinked *ul_fish(struct gfs2_sbd *sdp) +{ + struct list_head *head; + struct gfs2_unlinked *ul; + int found = 0; + + if (sdp->sd_vfs->s_flags & MS_RDONLY) + return NULL; + + spin_lock(&sdp->sd_unlinked_spin); + + head = &sdp->sd_unlinked_list; + + list_for_each_entry(ul, head, ul_list) { + if (test_bit(ULF_LOCKED, &ul->ul_flags)) + continue; + + list_move_tail(&ul->ul_list, head); + ul->ul_count++; + set_bit(ULF_LOCKED, &ul->ul_flags); + found = 1; + + break; + } + + if (!found) + ul = NULL; + + spin_unlock(&sdp->sd_unlinked_spin); + + return ul; +} + +/** + * enforce_limit - limit the number of inodes waiting to be deallocated + * @sdp: the filesystem + * + * Returns: errno + */ + +static void enforce_limit(struct gfs2_sbd *sdp) +{ + unsigned int tries = 0, min = 0; + int error; + + if (atomic_read(&sdp->sd_unlinked_count) >= + gfs2_tune_get(sdp, gt_ilimit)) { + tries = gfs2_tune_get(sdp, gt_ilimit_tries); + min = gfs2_tune_get(sdp, gt_ilimit_min); + } + + while (tries--) { + struct gfs2_unlinked *ul = ul_fish(sdp); + if (!ul) + break; + error = gfs2_inode_dealloc(sdp, ul); + gfs2_unlinked_put(sdp, ul); + + if (!error) { + if (!--min) + break; + } else if (error != 1) + break; + } +} + +static struct gfs2_unlinked *ul_alloc(struct gfs2_sbd *sdp) +{ + struct gfs2_unlinked *ul; + + ul = kzalloc(sizeof(struct gfs2_unlinked), GFP_KERNEL); + if (ul) { + INIT_LIST_HEAD(&ul->ul_list); + ul->ul_count = 1; + set_bit(ULF_LOCKED, &ul->ul_flags); + } + + return ul; +} + +int gfs2_unlinked_get(struct gfs2_sbd *sdp, struct gfs2_unlinked **ul) +{ + unsigned int c, o = 0, b; + unsigned char byte = 0; + + enforce_limit(sdp); + + *ul = ul_alloc(sdp); + if (!*ul) + return -ENOMEM; + + spin_lock(&sdp->sd_unlinked_spin); + + for (c = 0; c < sdp->sd_unlinked_chunks; c++) + for (o = 0; o < PAGE_SIZE; o++) { + byte = sdp->sd_unlinked_bitmap[c][o]; + if (byte != 0xFF) + goto found; + } + + goto fail; + + found: + for (b = 0; b < 8; b++) + if (!(byte & (1 << b))) + break; + (*ul)->ul_slot = c * (8 * PAGE_SIZE) + o * 8 + b; + + if ((*ul)->ul_slot >= sdp->sd_unlinked_slots) + goto fail; + + sdp->sd_unlinked_bitmap[c][o] |= 1 << b; + + spin_unlock(&sdp->sd_unlinked_spin); + + return 0; + + fail: + spin_unlock(&sdp->sd_unlinked_spin); + kfree(*ul); + return -ENOSPC; +} + +void gfs2_unlinked_put(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul) +{ + gfs2_assert_warn(sdp, test_and_clear_bit(ULF_LOCKED, &ul->ul_flags)); + + spin_lock(&sdp->sd_unlinked_spin); + gfs2_assert(sdp, ul->ul_count); + ul->ul_count--; + if (!ul->ul_count) { + gfs2_icbit_munge(sdp, sdp->sd_unlinked_bitmap, ul->ul_slot, 0); + spin_unlock(&sdp->sd_unlinked_spin); + kfree(ul); + } else + spin_unlock(&sdp->sd_unlinked_spin); +} + +int gfs2_unlinked_ondisk_add(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul) +{ + int error; + + gfs2_assert_warn(sdp, test_bit(ULF_LOCKED, &ul->ul_flags)); + gfs2_assert_warn(sdp, list_empty(&ul->ul_list)); + + error = munge_ondisk(sdp, ul->ul_slot, &ul->ul_ut); + if (!error) + ul_hash(sdp, ul); + + return error; +} + +int gfs2_unlinked_ondisk_munge(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul) +{ + int error; + + gfs2_assert_warn(sdp, test_bit(ULF_LOCKED, &ul->ul_flags)); + gfs2_assert_warn(sdp, !list_empty(&ul->ul_list)); + + error = munge_ondisk(sdp, ul->ul_slot, &ul->ul_ut); + + return error; +} + +int gfs2_unlinked_ondisk_rm(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul) +{ + struct gfs2_unlinked_tag ut; + int error; + + gfs2_assert_warn(sdp, test_bit(ULF_LOCKED, &ul->ul_flags)); + gfs2_assert_warn(sdp, !list_empty(&ul->ul_list)); + + memset(&ut, 0, sizeof(struct gfs2_unlinked_tag)); + + error = munge_ondisk(sdp, ul->ul_slot, &ut); + if (error) + return error; + + ul_unhash(sdp, ul); + + return 0; +} + +/** + * gfs2_unlinked_dealloc - Go through the list of inodes to be deallocated + * @sdp: the filesystem + * + * Returns: errno + */ + +int gfs2_unlinked_dealloc(struct gfs2_sbd *sdp) +{ + unsigned int hits, strikes; + int error; + + for (;;) { + hits = 0; + strikes = 0; + + for (;;) { + struct gfs2_unlinked *ul = ul_fish(sdp); + if (!ul) + return 0; + error = gfs2_inode_dealloc(sdp, ul); + gfs2_unlinked_put(sdp, ul); + + if (!error) { + hits++; + if (strikes) + strikes--; + } else if (error == 1) { + strikes++; + if (strikes >= + atomic_read(&sdp->sd_unlinked_count)) { + error = 0; + break; + } + } else + return error; + } + + if (!hits || kthread_should_stop()) + break; + + cond_resched(); + } + + return 0; +} + +int gfs2_unlinked_init(struct gfs2_sbd *sdp) +{ + struct gfs2_inode *ip = sdp->sd_ut_inode; + unsigned int blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift; + unsigned int x, slot = 0; + unsigned int found = 0; + uint64_t dblock; + uint32_t extlen = 0; + int error; + + if (!ip->i_di.di_size || + ip->i_di.di_size > (64 << 20) || + ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1)) { + gfs2_consist_inode(ip); + return -EIO; + } + sdp->sd_unlinked_slots = blocks * sdp->sd_ut_per_block; + sdp->sd_unlinked_chunks = DIV_RU(sdp->sd_unlinked_slots, 8 * PAGE_SIZE); + + error = -ENOMEM; + + sdp->sd_unlinked_bitmap = kcalloc(sdp->sd_unlinked_chunks, + sizeof(unsigned char *), + GFP_KERNEL); + if (!sdp->sd_unlinked_bitmap) + return error; + + for (x = 0; x < sdp->sd_unlinked_chunks; x++) { + sdp->sd_unlinked_bitmap[x] = kzalloc(PAGE_SIZE, GFP_KERNEL); + if (!sdp->sd_unlinked_bitmap[x]) + goto fail; + } + + for (x = 0; x < blocks; x++) { + struct buffer_head *bh; + unsigned int y; + + if (!extlen) { + int new = 0; + error = gfs2_block_map(ip, x, &new, &dblock, &extlen); + if (error) + goto fail; + } + gfs2_meta_ra(ip->i_gl, dblock, extlen); + error = gfs2_meta_read(ip->i_gl, dblock, DIO_START | DIO_WAIT, + &bh); + if (error) + goto fail; + error = -EIO; + if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_UT)) { + brelse(bh); + goto fail; + } + + for (y = 0; + y < sdp->sd_ut_per_block && slot < sdp->sd_unlinked_slots; + y++, slot++) { + struct gfs2_unlinked_tag ut; + struct gfs2_unlinked *ul; + + gfs2_unlinked_tag_in(&ut, bh->b_data + + sizeof(struct gfs2_meta_header) + + y * sizeof(struct gfs2_unlinked_tag)); + if (!ut.ut_inum.no_addr) + continue; + + error = -ENOMEM; + ul = ul_alloc(sdp); + if (!ul) { + brelse(bh); + goto fail; + } + ul->ul_ut = ut; + ul->ul_slot = slot; + + spin_lock(&sdp->sd_unlinked_spin); + gfs2_icbit_munge(sdp, sdp->sd_unlinked_bitmap, slot, 1); + spin_unlock(&sdp->sd_unlinked_spin); + ul_hash(sdp, ul); + + gfs2_unlinked_put(sdp, ul); + found++; + } + + brelse(bh); + dblock++; + extlen--; + } + + if (found) + fs_info(sdp, "found %u unlinked inodes\n", found); + + return 0; + + fail: + gfs2_unlinked_cleanup(sdp); + return error; +} + +/** + * gfs2_unlinked_cleanup - get rid of any extra struct gfs2_unlinked structures + * @sdp: the filesystem + * + */ + +void gfs2_unlinked_cleanup(struct gfs2_sbd *sdp) +{ + struct list_head *head = &sdp->sd_unlinked_list; + struct gfs2_unlinked *ul; + unsigned int x; + + spin_lock(&sdp->sd_unlinked_spin); + while (!list_empty(head)) { + ul = list_entry(head->next, struct gfs2_unlinked, ul_list); + + if (ul->ul_count > 1) { + list_move_tail(&ul->ul_list, head); + spin_unlock(&sdp->sd_unlinked_spin); + schedule(); + spin_lock(&sdp->sd_unlinked_spin); + continue; + } + + list_del_init(&ul->ul_list); + atomic_dec(&sdp->sd_unlinked_count); + + gfs2_assert_warn(sdp, ul->ul_count == 1); + gfs2_assert_warn(sdp, !test_bit(ULF_LOCKED, &ul->ul_flags)); + kfree(ul); + } + spin_unlock(&sdp->sd_unlinked_spin); + + gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_unlinked_count)); + + if (sdp->sd_unlinked_bitmap) { + for (x = 0; x < sdp->sd_unlinked_chunks; x++) + kfree(sdp->sd_unlinked_bitmap[x]); + kfree(sdp->sd_unlinked_bitmap); + } +} + |