cregit-Linux how code gets into the kernel

Release 4.18 fs/hpfs/alloc.c

Directory: fs/hpfs
// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/hpfs/alloc.c
 *
 *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
 *
 *  HPFS bitmap operations
 */

#include "hpfs_fn.h"


static void hpfs_claim_alloc(struct super_block *s, secno sec) { struct hpfs_sb_info *sbi = hpfs_sb(s); if (sbi->sb_n_free != (unsigned)-1) { if (unlikely(!sbi->sb_n_free)) { hpfs_error(s, "free count underflow, allocating sector %08x", sec); sbi->sb_n_free = -1; return; } sbi->sb_n_free--; } }

Contributors

PersonTokensPropCommitsCommitProp
Mikulas Patocka72100.00%1100.00%
Total72100.00%1100.00%


static void hpfs_claim_free(struct super_block *s, secno sec) { struct hpfs_sb_info *sbi = hpfs_sb(s); if (sbi->sb_n_free != (unsigned)-1) { if (unlikely(sbi->sb_n_free >= sbi->sb_fs_size)) { hpfs_error(s, "free count overflow, freeing sector %08x", sec); sbi->sb_n_free = -1; return; } sbi->sb_n_free++; } }

Contributors

PersonTokensPropCommitsCommitProp
Mikulas Patocka75100.00%1100.00%
Total75100.00%1100.00%


static void hpfs_claim_dirband_alloc(struct super_block *s, secno sec) { struct hpfs_sb_info *sbi = hpfs_sb(s); if (sbi->sb_n_free_dnodes != (unsigned)-1) { if (unlikely(!sbi->sb_n_free_dnodes)) { hpfs_error(s, "dirband free count underflow, allocating sector %08x", sec); sbi->sb_n_free_dnodes = -1; return; } sbi->sb_n_free_dnodes--; } }

Contributors

PersonTokensPropCommitsCommitProp
Mikulas Patocka72100.00%1100.00%
Total72100.00%1100.00%


static void hpfs_claim_dirband_free(struct super_block *s, secno sec) { struct hpfs_sb_info *sbi = hpfs_sb(s); if (sbi->sb_n_free_dnodes != (unsigned)-1) { if (unlikely(sbi->sb_n_free_dnodes >= sbi->sb_dirband_size / 4)) { hpfs_error(s, "dirband free count overflow, freeing sector %08x", sec); sbi->sb_n_free_dnodes = -1; return; } sbi->sb_n_free_dnodes++; } }

Contributors

PersonTokensPropCommitsCommitProp
Mikulas Patocka77100.00%1100.00%
Total77100.00%1100.00%

/* * Check if a sector is allocated in bitmap * This is really slow. Turned on only if chk==2 */
static int chk_if_allocated(struct super_block *s, secno sec, char *msg) { struct quad_buffer_head qbh; __le32 *bmp; if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "chk"))) goto fail; if ((le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) >> (sec & 0x1f)) & 1) { hpfs_error(s, "sector '%s' - %08x not allocated in bitmap", msg, sec); goto fail1; } hpfs_brelse4(&qbh); if (sec >= hpfs_sb(s)->sb_dirband_start && sec < hpfs_sb(s)->sb_dirband_start + hpfs_sb(s)->sb_dirband_size) { unsigned ssec = (sec - hpfs_sb(s)->sb_dirband_start) / 4; if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto fail; if ((le32_to_cpu(bmp[ssec >> 5]) >> (ssec & 0x1f)) & 1) { hpfs_error(s, "sector '%s' - %08x not allocated in directory bitmap", msg, sec); goto fail1; } hpfs_brelse4(&qbh); } return 0; fail1: hpfs_brelse4(&qbh); fail: return 1; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)19889.59%125.00%
Brian Gerst167.24%125.00%
Mikulas Patocka52.26%125.00%
Al Viro20.90%125.00%
Total221100.00%4100.00%

/* * Check if sector(s) have proper number and additionally check if they're * allocated in bitmap. */
int hpfs_chk_sectors(struct super_block *s, secno start, int len, char *msg) { if (start + len < start || start < 0x12 || start + len > hpfs_sb(s)->sb_fs_size) { hpfs_error(s, "sector(s) '%s' badly placed at %08x", msg, start); return 1; } if (hpfs_sb(s)->sb_chk>=2) { int i; for (i = 0; i < len; i++) if (chk_if_allocated(s, start + i, msg)) return 1; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)9992.52%150.00%
Brian Gerst87.48%150.00%
Total107100.00%2100.00%


static secno alloc_in_bmp(struct super_block *s, secno near, unsigned n, unsigned forward) { struct quad_buffer_head qbh; __le32 *bmp; unsigned bs = near & ~0x3fff; unsigned nr = (near & 0x3fff) & ~(n - 1); /*unsigned mnr;*/ unsigned i, q; int a, b; secno ret = 0; if (n != 1 && n != 4) { hpfs_error(s, "Bad allocation size: %d", n); return 0; } if (bs != ~0x3fff) { if (!(bmp = hpfs_map_bitmap(s, near >> 14, &qbh, "aib"))) goto uls; } else { if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto uls; } if (!tstbits(bmp, nr, n + forward)) { ret = bs + nr; goto rt; } q = nr + n; b = 0; while ((a = tstbits(bmp, q, n + forward)) != 0) { q += a; if (n != 1) q = ((q-1)&~(n-1))+n; if (!b) { if (q>>5 != nr>>5) { b = 1; q = nr & 0x1f; } } else if (q > nr) break; } if (!a) { ret = bs + q; goto rt; } nr >>= 5; /*for (i = nr + 1; i != nr; i++, i &= 0x1ff) */ i = nr; do { if (!le32_to_cpu(bmp[i])) goto cont; if (n + forward >= 0x3f && le32_to_cpu(bmp[i]) != 0xffffffff) goto cont; q = i<<5; if (i > 0) { unsigned k = le32_to_cpu(bmp[i-1]); while (k & 0x80000000) { q--; k <<= 1; } } if (n != 1) q = ((q-1)&~(n-1))+n; while ((a = tstbits(bmp, q, n + forward)) != 0) { q += a; if (n != 1) q = ((q-1)&~(n-1))+n; if (q>>5 > i) break; } if (!a) { ret = bs + q; goto rt; } cont: i++, i &= 0x1ff; } while (i != nr); rt: if (ret) { if (hpfs_sb(s)->sb_chk && ((ret >> 14) != (bs >> 14) || (le32_to_cpu(bmp[(ret & 0x3fff) >> 5]) | ~(((1 << n) - 1) << (ret & 0x1f))) != 0xffffffff)) { hpfs_error(s, "Allocation doesn't work! Wanted %d, allocated at %08x", n, ret); ret = 0; goto b; } bmp[(ret & 0x3fff) >> 5] &= cpu_to_le32(~(((1 << n) - 1) << (ret & 0x1f))); hpfs_mark_4buffers_dirty(&qbh); } b: hpfs_brelse4(&qbh); uls: return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)55488.08%116.67%
Mikulas Patocka6610.49%233.33%
Andrew Morton40.64%116.67%
Brian Gerst40.64%116.67%
Al Viro10.16%116.67%
Total629100.00%6100.00%

/* * Allocation strategy: 1) search place near the sector specified * 2) search bitmap where free sectors last found * 3) search all bitmaps * 4) search all bitmaps ignoring number of pre-allocated * sectors */
secno hpfs_alloc_sector(struct super_block *s, secno near, unsigned n, int forward) { secno sec; int i; unsigned n_bmps; struct hpfs_sb_info *sbi = hpfs_sb(s); int f_p = 0; int near_bmp; if (forward < 0) { forward = -forward; f_p = 1; } n_bmps = (sbi->sb_fs_size + 0x4000 - 1) >> 14; if (near && near < sbi->sb_fs_size) { if ((sec = alloc_in_bmp(s, near, n, f_p ? forward : forward/4))) goto ret; near_bmp = near >> 14; } else near_bmp = n_bmps / 2; /* if (b != -1) { if ((sec = alloc_in_bmp(s, b<<14, n, f_p ? forward : forward/2))) { b &= 0x0fffffff; goto ret; } if (b > 0x10000000) if ((sec = alloc_in_bmp(s, (b&0xfffffff)<<14, n, f_p ? forward : 0))) goto ret; */ if (!f_p) if (forward > sbi->sb_max_fwd_alloc) forward = sbi->sb_max_fwd_alloc; less_fwd: for (i = 0; i < n_bmps; i++) { if (near_bmp+i < n_bmps && ((sec = alloc_in_bmp(s, (near_bmp+i) << 14, n, forward)))) { sbi->sb_c_bitmap = near_bmp+i; goto ret; } if (!forward) { if (near_bmp-i-1 >= 0 && ((sec = alloc_in_bmp(s, (near_bmp-i-1) << 14, n, forward)))) { sbi->sb_c_bitmap = near_bmp-i-1; goto ret; } } else { if (near_bmp+i >= n_bmps && ((sec = alloc_in_bmp(s, (near_bmp+i-n_bmps) << 14, n, forward)))) { sbi->sb_c_bitmap = near_bmp+i-n_bmps; goto ret; } } if (i == 1 && sbi->sb_c_bitmap != -1 && ((sec = alloc_in_bmp(s, (sbi->sb_c_bitmap) << 14, n, forward)))) { goto ret; } } if (!f_p) { if (forward) { sbi->sb_max_fwd_alloc = forward * 3 / 4; forward /= 2; goto less_fwd; } } sec = 0; ret: if (sec) { i = 0; do hpfs_claim_alloc(s, sec + i); while (unlikely(++i < n)); } if (sec && f_p) { for (i = 0; i < forward; i++) { if (!hpfs_alloc_if_possible(s, sec + n + i)) { hpfs_error(s, "Prealloc doesn't work! Wanted %d, allocated at %08x, can't allocate %d", forward, sec, i); sec = 0; break; } } } return sec; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)30061.86%233.33%
Mikulas Patocka16534.02%350.00%
Brian Gerst204.12%116.67%
Total485100.00%6100.00%


static secno alloc_in_dirband(struct super_block *s, secno near) { unsigned nr = near; secno sec; struct hpfs_sb_info *sbi = hpfs_sb(s); if (nr < sbi->sb_dirband_start) nr = sbi->sb_dirband_start; if (nr >= sbi->sb_dirband_start + sbi->sb_dirband_size) nr = sbi->sb_dirband_start + sbi->sb_dirband_size - 4; nr -= sbi->sb_dirband_start; nr >>= 2; sec = alloc_in_bmp(s, (~0x3fff) | nr, 1, 0); if (!sec) return 0; hpfs_claim_dirband_alloc(s, sec); return ((sec & 0x3fff) << 2) + sbi->sb_dirband_start; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)9574.22%133.33%
Brian Gerst2620.31%133.33%
Mikulas Patocka75.47%133.33%
Total128100.00%3100.00%

/* Alloc sector if it's free */
int hpfs_alloc_if_possible(struct super_block *s, secno sec) { struct quad_buffer_head qbh; __le32 *bmp; if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "aip"))) goto end; if (le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) & (1 << (sec & 0x1f))) { bmp[(sec & 0x3fff) >> 5] &= cpu_to_le32(~(1 << (sec & 0x1f))); hpfs_mark_4buffers_dirty(&qbh); hpfs_brelse4(&qbh); hpfs_claim_alloc(s, sec); return 1; } hpfs_brelse4(&qbh); end: return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)11688.55%120.00%
Mikulas Patocka1410.69%360.00%
Al Viro10.76%120.00%
Total131100.00%5100.00%

/* Free sectors in bitmaps */
void hpfs_free_sectors(struct super_block *s, secno sec, unsigned n) { struct quad_buffer_head qbh; __le32 *bmp; struct hpfs_sb_info *sbi = hpfs_sb(s); /*pr_info("2 - ");*/ if (!n) return; if (sec < 0x12) { hpfs_error(s, "Trying to free reserved sector %08x", sec); return; } sbi->sb_max_fwd_alloc += n > 0xffff ? 0xffff : n; if (sbi->sb_max_fwd_alloc > 0xffffff) sbi->sb_max_fwd_alloc = 0xffffff; new_map: if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "free"))) { return; } new_tst: if ((le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) >> (sec & 0x1f) & 1)) { hpfs_error(s, "sector %08x not allocated", sec); hpfs_brelse4(&qbh); return; } bmp[(sec & 0x3fff) >> 5] |= cpu_to_le32(1 << (sec & 0x1f)); hpfs_claim_free(s, sec); if (!--n) { hpfs_mark_4buffers_dirty(&qbh); hpfs_brelse4(&qbh); return; } if (!(++sec & 0x3fff)) { hpfs_mark_4buffers_dirty(&qbh); hpfs_brelse4(&qbh); goto new_map; } goto new_tst; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)18678.48%116.67%
Mikulas Patocka4920.68%350.00%
Fabian Frederick10.42%116.67%
Al Viro10.42%116.67%
Total237100.00%6100.00%

/* * Check if there are at least n free dnodes on the filesystem. * Called before adding to dnode. If we run out of space while * splitting dnodes, it would corrupt dnode tree. */
int hpfs_check_free_dnodes(struct super_block *s, int n) { int n_bmps = (hpfs_sb(s)->sb_fs_size + 0x4000 - 1) >> 14; int b = hpfs_sb(s)->sb_c_bitmap & 0x0fffffff; int i, j; __le32 *bmp; struct quad_buffer_head qbh; if ((bmp = hpfs_map_dnode_bitmap(s, &qbh))) { for (j = 0; j < 512; j++) { unsigned k; if (!le32_to_cpu(bmp[j])) continue; for (k = le32_to_cpu(bmp[j]); k; k >>= 1) if (k & 1) if (!--n) { hpfs_brelse4(&qbh); return 0; } } } hpfs_brelse4(&qbh); i = 0; if (hpfs_sb(s)->sb_c_bitmap != -1) { bmp = hpfs_map_bitmap(s, b, &qbh, "chkdn1"); goto chk_bmp; } chk_next: if (i == b) i++; if (i >= n_bmps) return 1; bmp = hpfs_map_bitmap(s, i, &qbh, "chkdn2"); chk_bmp: if (bmp) { for (j = 0; j < 512; j++) { u32 k; if (!le32_to_cpu(bmp[j])) continue; for (k = 0xf; k; k <<= 4) if ((le32_to_cpu(bmp[j]) & k) == k) { if (!--n) { hpfs_brelse4(&qbh); return 0; } } } hpfs_brelse4(&qbh); } i++; goto chk_next; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)28991.75%240.00%
Mikulas Patocka134.13%120.00%
Brian Gerst123.81%120.00%
Al Viro10.32%120.00%
Total315100.00%5100.00%


void hpfs_free_dnode(struct super_block *s, dnode_secno dno) { if (hpfs_sb(s)->sb_chk) if (dno & 3) { hpfs_error(s, "hpfs_free_dnode: dnode %08x not aligned", dno); return; } if (dno < hpfs_sb(s)->sb_dirband_start || dno >= hpfs_sb(s)->sb_dirband_start + hpfs_sb(s)->sb_dirband_size) { hpfs_free_sectors(s, dno, 4); } else { struct quad_buffer_head qbh; __le32 *bmp; unsigned ssec = (dno - hpfs_sb(s)->sb_dirband_start) / 4; if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) { return; } bmp[ssec >> 5] |= cpu_to_le32(1 << (ssec & 0x1f)); hpfs_mark_4buffers_dirty(&qbh); hpfs_brelse4(&qbh); hpfs_claim_dirband_free(s, dno); } }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)12980.62%120.00%
Brian Gerst2012.50%120.00%
Mikulas Patocka106.25%240.00%
Al Viro10.62%120.00%
Total160100.00%5100.00%


struct dnode *hpfs_alloc_dnode(struct super_block *s, secno near, dnode_secno *dno, struct quad_buffer_head *qbh) { struct dnode *d; if (hpfs_get_free_dnodes(s) > FREE_DNODES_ADD) { if (!(*dno = alloc_in_dirband(s, near))) if (!(*dno = hpfs_alloc_sector(s, near, 4, 0))) return NULL; } else { if (!(*dno = hpfs_alloc_sector(s, near, 4, 0))) if (!(*dno = alloc_in_dirband(s, near))) return NULL; } if (!(d = hpfs_get_4sectors(s, *dno, qbh))) { hpfs_free_dnode(s, *dno); return NULL; } memset(d, 0, 2048); d->magic = cpu_to_le32(DNODE_MAGIC); d->first_free = cpu_to_le32(52); d->dirent[0] = 32; d->dirent[2] = 8; d->dirent[30] = 1; d->dirent[31] = 255; d->self = cpu_to_le32(*dno); return d; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)21194.62%240.00%
Mikulas Patocka104.48%240.00%
Brian Gerst20.90%120.00%
Total223100.00%5100.00%


struct fnode *hpfs_alloc_fnode(struct super_block *s, secno near, fnode_secno *fno, struct buffer_head **bh) { struct fnode *f; if (!(*fno = hpfs_alloc_sector(s, near, 1, FNODE_ALLOC_FWD))) return NULL; if (!(f = hpfs_get_sector(s, *fno, bh))) { hpfs_free_sectors(s, *fno, 1); return NULL; } memset(f, 0, 512); f->magic = cpu_to_le32(FNODE_MAGIC); f->ea_offs = cpu_to_le16(0xc4); f->btree.n_free_nodes = 8; f->btree.first_free = cpu_to_le16(8); return f; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)12493.23%150.00%
Mikulas Patocka96.77%150.00%
Total133100.00%2100.00%


struct anode *hpfs_alloc_anode(struct super_block *s, secno near, anode_secno *ano, struct buffer_head **bh) { struct anode *a; if (!(*ano = hpfs_alloc_sector(s, near, 1, ANODE_ALLOC_FWD))) return NULL; if (!(a = hpfs_get_sector(s, *ano, bh))) { hpfs_free_sectors(s, *ano, 1); return NULL; } memset(a, 0, 512); a->magic = cpu_to_le32(ANODE_MAGIC); a->self = cpu_to_le32(*ano); a->btree.n_free_nodes = 40; a->btree.n_used_nodes = 0; a->btree.first_free = cpu_to_le16(8); return a; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)13393.66%150.00%
Mikulas Patocka96.34%150.00%
Total142100.00%2100.00%


static unsigned find_run(__le32 *bmp, unsigned *idx) { unsigned len; while (tstbits(bmp, *idx, 1)) { (*idx)++; if (unlikely(*idx >= 0x4000)) return 0; } len = 1; while (!tstbits(bmp, *idx + len, 1)) len++; return len; }

Contributors

PersonTokensPropCommitsCommitProp
Mikulas Patocka75100.00%1100.00%
Total75100.00%1100.00%


static int do_trim(struct super_block *s, secno start, unsigned len, secno limit_start, secno limit_end, unsigned minlen, unsigned *result) { int err; secno end; if (fatal_signal_pending(current)) return -EINTR; end = start + len; if (start < limit_start) start = limit_start; if (end > limit_end) end = limit_end; if (start >= end) return 0; if (end - start < minlen) return 0; err = sb_issue_discard(s, start, end - start, GFP_NOFS, 0); if (err) return err; *result += end - start; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Mikulas Patocka127100.00%1100.00%
Total127100.00%1100.00%


int hpfs_trim_fs(struct super_block *s, u64 start, u64 end, u64 minlen, unsigned *result) { int err = 0; struct hpfs_sb_info *sbi = hpfs_sb(s); unsigned idx, len, start_bmp, end_bmp; __le32 *bmp; struct quad_buffer_head qbh; *result = 0; if (!end || end > sbi->sb_fs_size) end = sbi->sb_fs_size; if (start >= sbi->sb_fs_size) return 0; if (minlen > 0x4000) return 0; if (start < sbi->sb_dirband_start + sbi->sb_dirband_size && end > sbi->sb_dirband_start) { hpfs_lock(s); if (sb_rdonly(s)) { err = -EROFS; goto unlock_1; } if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) { err = -EIO; goto unlock_1; } idx = 0; while ((len = find_run(bmp, &idx)) && !err) { err = do_trim(s, sbi->sb_dirband_start + idx * 4, len * 4, start, end, minlen, result); idx += len; } hpfs_brelse4(&qbh); unlock_1: hpfs_unlock(s); } start_bmp = start >> 14; end_bmp = (end + 0x3fff) >> 14; while (start_bmp < end_bmp && !err) { hpfs_lock(s); if (sb_rdonly(s)) { err = -EROFS; goto unlock_2; } if (!(bmp = hpfs_map_bitmap(s, start_bmp, &qbh, "trim"))) { err = -EIO; goto unlock_2; } idx = 0; while ((len = find_run(bmp, &idx)) && !err) { err = do_trim(s, (start_bmp << 14) + idx, len, start, end, minlen, result); idx += len; } hpfs_brelse4(&qbh); unlock_2: hpfs_unlock(s); start_bmp++; } return err; }

Contributors

PersonTokensPropCommitsCommitProp
Mikulas Patocka37498.42%150.00%
David Howells61.58%150.00%
Total380100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)244464.32%321.43%
Mikulas Patocka122932.34%535.71%
Brian Gerst1082.84%17.14%
Al Viro70.18%17.14%
David Howells60.16%17.14%
Andrew Morton40.11%17.14%
Fabian Frederick10.03%17.14%
Greg Kroah-Hartman10.03%17.14%
Total3800100.00%14100.00%
Directory: fs/hpfs
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