cregit-Linux how code gets into the kernel

Release 4.18 fs/reiserfs/resize.c

Directory: fs/reiserfs
/*
 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
 */

/*
 * Written by Alexander Zarochentcev.
 *
 * The kernel part of the (on-line) reiserfs resizer.
 */

#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/string.h>
#include <linux/errno.h>
#include "reiserfs.h"
#include <linux/buffer_head.h>


int reiserfs_resize(struct super_block *s, unsigned long block_count_new) { int err = 0; struct reiserfs_super_block *sb; struct reiserfs_bitmap_info *bitmap; struct reiserfs_bitmap_info *info; struct reiserfs_bitmap_info *old_bitmap = SB_AP_BITMAP(s); struct buffer_head *bh; struct reiserfs_transaction_handle th; unsigned int bmap_nr_new, bmap_nr; unsigned int block_r_new, block_r; struct reiserfs_list_bitmap *jb; struct reiserfs_list_bitmap jbitmap[JOURNAL_NUM_BITMAPS]; unsigned long int block_count, free_blocks; int i; int copy_size; int depth; sb = SB_DISK_SUPER_BLOCK(s); if (SB_BLOCK_COUNT(s) >= block_count_new) { printk("can\'t shrink filesystem on-line\n"); return -EINVAL; } /* check the device size */ depth = reiserfs_write_unlock_nested(s); bh = sb_bread(s, block_count_new - 1); reiserfs_write_lock_nested(s, depth); if (!bh) { printk("reiserfs_resize: can\'t read last block\n"); return -EINVAL; } bforget(bh); /* * old disk layout detection; those partitions can be mounted, but * cannot be resized */ if (SB_BUFFER_WITH_SB(s)->b_blocknr * SB_BUFFER_WITH_SB(s)->b_size != REISERFS_DISK_OFFSET_IN_BYTES) { printk ("reiserfs_resize: unable to resize a reiserfs without distributed bitmap (fs version < 3.5.12)\n"); return -ENOTSUPP; } /* count used bits in last bitmap block */ block_r = SB_BLOCK_COUNT(s) - (reiserfs_bmap_count(s) - 1) * s->s_blocksize * 8; /* count bitmap blocks in new fs */ bmap_nr_new = block_count_new / (s->s_blocksize * 8); block_r_new = block_count_new - bmap_nr_new * s->s_blocksize * 8; if (block_r_new) bmap_nr_new++; else block_r_new = s->s_blocksize * 8; /* save old values */ block_count = SB_BLOCK_COUNT(s); bmap_nr = reiserfs_bmap_count(s); /* resizing of reiserfs bitmaps (journal and real), if needed */ if (bmap_nr_new > bmap_nr) { /* reallocate journal bitmaps */ if (reiserfs_allocate_list_bitmaps(s, jbitmap, bmap_nr_new) < 0) { printk ("reiserfs_resize: unable to allocate memory for journal bitmaps\n"); return -ENOMEM; } /* * the new journal bitmaps are zero filled, now we copy i * the bitmap node pointers from the old journal bitmap * structs, and then transfer the new data structures * into the journal struct. * * using the copy_size var below allows this code to work for * both shrinking and expanding the FS. */ copy_size = bmap_nr_new < bmap_nr ? bmap_nr_new : bmap_nr; copy_size = copy_size * sizeof(struct reiserfs_list_bitmap_node *); for (i = 0; i < JOURNAL_NUM_BITMAPS; i++) { struct reiserfs_bitmap_node **node_tmp; jb = SB_JOURNAL(s)->j_list_bitmap + i; memcpy(jbitmap[i].bitmaps, jb->bitmaps, copy_size); /* * just in case vfree schedules on us, copy the new * pointer into the journal struct before freeing the * old one */ node_tmp = jb->bitmaps; jb->bitmaps = jbitmap[i].bitmaps; vfree(node_tmp); } /* * allocate additional bitmap blocks, reallocate * array of bitmap block pointers */ bitmap = vzalloc(array_size(bmap_nr_new, sizeof(struct reiserfs_bitmap_info))); if (!bitmap) { /* * Journal bitmaps are still supersized, but the * memory isn't leaked, so I guess it's ok */ printk("reiserfs_resize: unable to allocate memory.\n"); return -ENOMEM; } for (i = 0; i < bmap_nr; i++) bitmap[i] = old_bitmap[i]; /* * This doesn't go through the journal, but it doesn't have to. * The changes are still atomic: We're synced up when the * journal transaction begins, and the new bitmaps don't * matter if the transaction fails. */ for (i = bmap_nr; i < bmap_nr_new; i++) { int depth; /* * don't use read_bitmap_block since it will cache * the uninitialized bitmap */ depth = reiserfs_write_unlock_nested(s); bh = sb_bread(s, i * s->s_blocksize * 8); reiserfs_write_lock_nested(s, depth); if (!bh) { vfree(bitmap); return -EIO; } memset(bh->b_data, 0, sb_blocksize(sb)); reiserfs_set_le_bit(0, bh->b_data); reiserfs_cache_bitmap_metadata(s, bh, bitmap + i); set_buffer_uptodate(bh); mark_buffer_dirty(bh); depth = reiserfs_write_unlock_nested(s); sync_dirty_buffer(bh); reiserfs_write_lock_nested(s, depth); /* update bitmap_info stuff */ bitmap[i].free_count = sb_blocksize(sb) * 8 - 1; brelse(bh); } /* free old bitmap blocks array */ SB_AP_BITMAP(s) = bitmap; vfree(old_bitmap); } /* * begin transaction, if there was an error, it's fine. Yes, we have * incorrect bitmaps now, but none of it is ever going to touch the * disk anyway. */ err = journal_begin(&th, s, 10); if (err) return err; /* Extend old last bitmap block - new blocks have been made available */ info = SB_AP_BITMAP(s) + bmap_nr - 1; bh = reiserfs_read_bitmap_block(s, bmap_nr - 1); if (!bh) { int jerr = journal_end(&th); if (jerr) return jerr; return -EIO; } reiserfs_prepare_for_journal(s, bh, 1); for (i = block_r; i < s->s_blocksize * 8; i++) reiserfs_clear_le_bit(i, bh->b_data); info->free_count += s->s_blocksize * 8 - block_r; journal_mark_dirty(&th, bh); brelse(bh); /* Correct new last bitmap block - It may not be full */ info = SB_AP_BITMAP(s) + bmap_nr_new - 1; bh = reiserfs_read_bitmap_block(s, bmap_nr_new - 1); if (!bh) { int jerr = journal_end(&th); if (jerr) return jerr; return -EIO; } reiserfs_prepare_for_journal(s, bh, 1); for (i = block_r_new; i < s->s_blocksize * 8; i++) reiserfs_set_le_bit(i, bh->b_data); journal_mark_dirty(&th, bh); brelse(bh); info->free_count -= s->s_blocksize * 8 - block_r_new; /* update super */ reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1); free_blocks = SB_FREE_BLOCKS(s); PUT_SB_FREE_BLOCKS(s, free_blocks + (block_count_new - block_count - (bmap_nr_new - bmap_nr))); PUT_SB_BLOCK_COUNT(s, block_count_new); PUT_SB_BMAP_NR(s, bmap_would_wrap(bmap_nr_new) ? : bmap_nr_new); journal_mark_dirty(&th, SB_BUFFER_WITH_SB(s)); SB_JOURNAL(s)->j_must_wait = 1; return journal_end(&th); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds64668.07%316.67%
Jeff Mahoney21322.44%738.89%
Oleg Drokin565.90%211.11%
Dmitriy Monakhov161.69%15.56%
Frédéric Weisbecker80.84%15.56%
Kees Cook50.53%15.56%
Akinobu Mita30.32%15.56%
Andrew Morton10.11%15.56%
Joe Perches10.11%15.56%
Total949100.00%18100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds66268.11%313.64%
Jeff Mahoney21522.12%836.36%
Oleg Drokin565.76%29.09%
Dmitriy Monakhov161.65%14.55%
Frédéric Weisbecker80.82%14.55%
Kees Cook50.51%14.55%
Akinobu Mita30.31%14.55%
Dave Jones30.31%14.55%
Al Viro10.10%14.55%
Andrew Morton10.10%14.55%
Joe Perches10.10%14.55%
Christoph Hellwig10.10%14.55%
Total972100.00%22100.00%
Directory: fs/reiserfs
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