From 79eb4dde742fe2e9c9e301432b894a7410261ce7 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 7 Jan 2011 17:49:24 +1100 Subject: cifs: dont overwrite dentry name in d_revalidate Use vfat's method for dealing with negative dentries to preserve case, rather than overwrite dentry name in d_revalidate, which is a bit ugly and also gets in the way of doing lock-free path walking. Signed-off-by: Nick Piggin --- fs/cifs/dir.c | 43 ++++++++++++++++++++++++------------------- 1 file changed, 24 insertions(+), 19 deletions(-) (limited to 'fs/cifs/dir.c') diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c index 3840eddbfb7a..521d841b1fd1 100644 --- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -656,22 +656,34 @@ lookup_out: static int cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd) { - int isValid = 1; - if (direntry->d_inode) { if (cifs_revalidate_dentry(direntry)) return 0; - } else { - cFYI(1, "neg dentry 0x%p name = %s", - direntry, direntry->d_name.name); - if (time_after(jiffies, direntry->d_time + HZ) || - !lookupCacheEnabled) { - d_drop(direntry); - isValid = 0; - } + else + return 1; } - return isValid; + /* + * This may be nfsd (or something), anyway, we can't see the + * intent of this. So, since this can be for creation, drop it. + */ + if (!nd) + return 0; + + /* + * Drop the negative dentry, in order to make sure to use the + * case sensitive name which is specified by user if this is + * for creation. + */ + if (!(nd->flags & (LOOKUP_CONTINUE | LOOKUP_PARENT))) { + if (nd->flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET)) + return 0; + } + + if (time_after(jiffies, direntry->d_time + HZ) || !lookupCacheEnabled) + return 0; + + return 1; } /* static int cifs_d_delete(struct dentry *direntry) @@ -709,15 +721,8 @@ static int cifs_ci_compare(struct dentry *dentry, struct qstr *a, struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls; if ((a->len == b->len) && - (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) { - /* - * To preserve case, don't let an existing negative dentry's - * case take precedence. If a is not a negative dentry, this - * should have no side effects - */ - memcpy((void *)a->name, b->name, a->len); + (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) return 0; - } return 1; } -- cgit v1.2.1 From 621e155a3591962420eacdd39f6f0aa29ceb221e Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 7 Jan 2011 17:49:27 +1100 Subject: fs: change d_compare for rcu-walk Change d_compare so it may be called from lock-free RCU lookups. This does put significant restrictions on what may be done from the callback, however there don't seem to have been any problems with in-tree fses. If some strange use case pops up that _really_ cannot cope with the rcu-walk rules, we can just add new rcu-unaware callbacks, which would cause name lookup to drop out of rcu-walk mode. For in-tree filesystems, this is just a mechanical change. Signed-off-by: Nick Piggin --- fs/cifs/dir.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'fs/cifs/dir.c') diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c index 521d841b1fd1..c60133f0d8e4 100644 --- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -715,13 +715,15 @@ static int cifs_ci_hash(struct dentry *dentry, struct qstr *q) return 0; } -static int cifs_ci_compare(struct dentry *dentry, struct qstr *a, - struct qstr *b) +static int cifs_ci_compare(const struct dentry *parent, + const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { - struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls; + struct nls_table *codepage = CIFS_SB(pinode->i_sb)->local_nls; - if ((a->len == b->len) && - (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) + if ((name->len == len) && + (nls_strnicmp(codepage, name->name, str, len) == 0)) return 0; return 1; } -- cgit v1.2.1 From b1e6a015a580ad145689ad1d6b4aa0e03e6c868b Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 7 Jan 2011 17:49:28 +1100 Subject: fs: change d_hash for rcu-walk Change d_hash so it may be called from lock-free RCU lookups. See similar patch for d_compare for details. For in-tree filesystems, this is just a mechanical change. Signed-off-by: Nick Piggin --- fs/cifs/dir.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'fs/cifs/dir.c') diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c index c60133f0d8e4..88bfe686ac00 100644 --- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -700,9 +700,10 @@ const struct dentry_operations cifs_dentry_ops = { /* d_delete: cifs_d_delete, */ /* not needed except for debugging */ }; -static int cifs_ci_hash(struct dentry *dentry, struct qstr *q) +static int cifs_ci_hash(const struct dentry *dentry, const struct inode *inode, + struct qstr *q) { - struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls; + struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls; unsigned long hash; int i; -- cgit v1.2.1 From fb045adb99d9b7c562dc7fef834857f78249daa1 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 7 Jan 2011 17:49:55 +1100 Subject: fs: dcache reduce branches in lookup path Reduce some branches and memory accesses in dcache lookup by adding dentry flags to indicate common d_ops are set, rather than having to check them. This saves a pointer memory access (dentry->d_op) in common path lookup situations, and saves another pointer load and branch in cases where we have d_op but not the particular operation. Patched with: git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i Signed-off-by: Nick Piggin --- fs/cifs/dir.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'fs/cifs/dir.c') diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c index 88bfe686ac00..e3b10ca6d453 100644 --- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -135,9 +135,9 @@ static void setup_cifs_dentry(struct cifsTconInfo *tcon, struct inode *newinode) { if (tcon->nocase) - direntry->d_op = &cifs_ci_dentry_ops; + d_set_d_op(direntry, &cifs_ci_dentry_ops); else - direntry->d_op = &cifs_dentry_ops; + d_set_d_op(direntry, &cifs_dentry_ops); d_instantiate(direntry, newinode); } @@ -421,9 +421,9 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode, rc = cifs_get_inode_info_unix(&newinode, full_path, inode->i_sb, xid); if (pTcon->nocase) - direntry->d_op = &cifs_ci_dentry_ops; + d_set_d_op(direntry, &cifs_ci_dentry_ops); else - direntry->d_op = &cifs_dentry_ops; + d_set_d_op(direntry, &cifs_dentry_ops); if (rc == 0) d_instantiate(direntry, newinode); @@ -604,9 +604,9 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, if ((rc == 0) && (newInode != NULL)) { if (pTcon->nocase) - direntry->d_op = &cifs_ci_dentry_ops; + d_set_d_op(direntry, &cifs_ci_dentry_ops); else - direntry->d_op = &cifs_dentry_ops; + d_set_d_op(direntry, &cifs_dentry_ops); d_add(direntry, newInode); if (posix_open) { filp = lookup_instantiate_filp(nd, direntry, @@ -634,9 +634,9 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, rc = 0; direntry->d_time = jiffies; if (pTcon->nocase) - direntry->d_op = &cifs_ci_dentry_ops; + d_set_d_op(direntry, &cifs_ci_dentry_ops); else - direntry->d_op = &cifs_dentry_ops; + d_set_d_op(direntry, &cifs_dentry_ops); d_add(direntry, NULL); /* if it was once a directory (but how can we tell?) we could do shrink_dcache_parent(direntry); */ -- cgit v1.2.1 From 34286d6662308d82aed891852d04c7c3a2649b16 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 7 Jan 2011 17:49:57 +1100 Subject: fs: rcu-walk aware d_revalidate method Require filesystems be aware of .d_revalidate being called in rcu-walk mode (nd->flags & LOOKUP_RCU). For now do a simple push down, returning -ECHILD from all implementations. Signed-off-by: Nick Piggin --- fs/cifs/dir.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs/cifs/dir.c') diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c index e3b10ca6d453..db2a58c00f7b 100644 --- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -656,6 +656,9 @@ lookup_out: static int cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd) { + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + if (direntry->d_inode) { if (cifs_revalidate_dentry(direntry)) return 0; -- cgit v1.2.1