8387ff2577
We always mixed in the parent pointer into the dentry name hash, but we did it late at lookup time. It turns out that we can simplify that lookup-time action by salting the hash with the parent pointer early instead of late. A few other users of our string hashes also wanted to mix in their own pointers into the hash, and those are updated to use the same mechanism. Hash users that don't have any particular initial salt can just use the NULL pointer as a no-salt. Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: George Spelvin <linux@sciencehorizons.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
62 lines
1.4 KiB
C
62 lines
1.4 KiB
C
/*
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* linux/fs/hpfs/dentry.c
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*
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* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
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*
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* dcache operations
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*/
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#include "hpfs_fn.h"
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/*
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* Note: the dentry argument is the parent dentry.
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*/
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static int hpfs_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
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{
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unsigned long hash;
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int i;
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unsigned l = qstr->len;
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if (l == 1) if (qstr->name[0]=='.') goto x;
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if (l == 2) if (qstr->name[0]=='.' || qstr->name[1]=='.') goto x;
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hpfs_adjust_length(qstr->name, &l);
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/*if (hpfs_chk_name(qstr->name,&l))*/
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/*return -ENAMETOOLONG;*/
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/*return -ENOENT;*/
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x:
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hash = init_name_hash(dentry);
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for (i = 0; i < l; i++)
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hash = partial_name_hash(hpfs_upcase(hpfs_sb(dentry->d_sb)->sb_cp_table,qstr->name[i]), hash);
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qstr->hash = end_name_hash(hash);
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return 0;
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}
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static int hpfs_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
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unsigned int len, const char *str, const struct qstr *name)
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{
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unsigned al = len;
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unsigned bl = name->len;
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hpfs_adjust_length(str, &al);
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/*hpfs_adjust_length(b->name, &bl);*/
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/*
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* 'str' is the nane of an already existing dentry, so the name
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* must be valid. 'name' must be validated first.
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*/
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if (hpfs_chk_name(name->name, &bl))
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return 1;
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if (hpfs_compare_names(parent->d_sb, str, al, name->name, bl, 0))
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return 1;
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return 0;
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}
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const struct dentry_operations hpfs_dentry_operations = {
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.d_hash = hpfs_hash_dentry,
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.d_compare = hpfs_compare_dentry,
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};
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