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author | Nick Piggin <npiggin@kernel.dk> | 2011-01-07 06:49:36 (GMT) |
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committer | Nick Piggin <npiggin@kernel.dk> | 2011-01-07 06:50:22 (GMT) |
commit | 9abca36087288fe28de4749c71ca003d4b9e3ed0 (patch) | |
tree | 1d1b08bdcffb8f8a7be217ee1c017f5154f64f6a /fs/dcache.c | |
parent | b23fb0a60379a95e10c671f646b259ea2558421e (diff) | |
download | linux-fsl-qoriq-9abca36087288fe28de4749c71ca003d4b9e3ed0.tar.xz |
fs: increase d_name lock coverage
Cover d_name with d_lock in more cases, where there may be concurrent
modification to it.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Diffstat (limited to 'fs/dcache.c')
-rw-r--r-- | fs/dcache.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index de38680..a09f077 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1350,6 +1350,11 @@ static struct dentry *__d_instantiate_unique(struct dentry *entry, list_for_each_entry(alias, &inode->i_dentry, d_alias) { struct qstr *qstr = &alias->d_name; + /* + * Don't need alias->d_lock here, because aliases with + * d_parent == entry->d_parent are not subject to name or + * parent changes, because the parent inode i_mutex is held. + */ if (qstr->hash != hash) continue; if (alias->d_parent != entry->d_parent) @@ -2313,7 +2318,9 @@ static int prepend_path(const struct path *path, struct path *root, } parent = dentry->d_parent; prefetch(parent); + spin_lock(&dentry->d_lock); error = prepend_name(buffer, buflen, &dentry->d_name); + spin_unlock(&dentry->d_lock); if (!error) error = prepend(buffer, buflen, "/", 1); if (error) @@ -2515,10 +2522,13 @@ static char *__dentry_path(struct dentry *dentry, char *buf, int buflen) while (!IS_ROOT(dentry)) { struct dentry *parent = dentry->d_parent; + int error; prefetch(parent); - if ((prepend_name(&end, &buflen, &dentry->d_name) != 0) || - (prepend(&end, &buflen, "/", 1) != 0)) + spin_lock(&dentry->d_lock); + error = prepend_name(&end, &buflen, &dentry->d_name); + spin_unlock(&dentry->d_lock); + if (error != 0 || prepend(&end, &buflen, "/", 1) != 0) goto Elong; retval = end; |