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| author | Suresh Jayaraman <sjayaraman@suse.de> | 2010-10-18 23:29:37 +0530 |
|---|---|---|
| committer | Steve French <sfrench@us.ibm.com> | 2010-10-21 13:14:27 +0000 |
| commit | 3f9bcca7820a6711307b6499952b13cfcfc31dd6 (patch) | |
| tree | 6c380f5877562778335d6794e1e4a297f8970d77 /fs/cifs/misc.c | |
| parent | 3e24e132878c83910b61eb7704511a6d96a0389f (diff) | |
| download | linux-stable-3f9bcca7820a6711307b6499952b13cfcfc31dd6.tar.gz linux-stable-3f9bcca7820a6711307b6499952b13cfcfc31dd6.tar.bz2 linux-stable-3f9bcca7820a6711307b6499952b13cfcfc31dd6.zip | |
cifs: convert cifs_tcp_ses_lock from a rwlock to a spinlock
cifs_tcp_ses_lock is a rwlock with protects the cifs_tcp_ses_list,
server->smb_ses_list and the ses->tcon_list. It also protects a few
ref counters in server, ses and tcon. In most cases the critical section
doesn't seem to be large, in a few cases where it is slightly large, there
seem to be really no benefit from concurrent access. I briefly considered RCU
mechanism but it appears to me that there is no real need.
Replace it with a spinlock and get rid of the last rwlock in the cifs code.
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Diffstat (limited to 'fs/cifs/misc.c')
| -rw-r--r-- | fs/cifs/misc.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index de6073cccd9c..a7b492c213cd 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -347,7 +347,7 @@ header_assemble(struct smb_hdr *buffer, char smb_command /* command */ , if (current_fsuid() != treeCon->ses->linux_uid) { cFYI(1, "Multiuser mode and UID " "did not match tcon uid"); - read_lock(&cifs_tcp_ses_lock); + spin_lock(&cifs_tcp_ses_lock); list_for_each(temp_item, &treeCon->ses->server->smb_ses_list) { ses = list_entry(temp_item, struct cifsSesInfo, smb_ses_list); if (ses->linux_uid == current_fsuid()) { @@ -361,7 +361,7 @@ header_assemble(struct smb_hdr *buffer, char smb_command /* command */ , } } } - read_unlock(&cifs_tcp_ses_lock); + spin_unlock(&cifs_tcp_ses_lock); } } } @@ -551,7 +551,7 @@ is_valid_oplock_break(struct smb_hdr *buf, struct TCP_Server_Info *srv) return false; /* look up tcon based on tid & uid */ - read_lock(&cifs_tcp_ses_lock); + spin_lock(&cifs_tcp_ses_lock); list_for_each(tmp, &srv->smb_ses_list) { ses = list_entry(tmp, struct cifsSesInfo, smb_ses_list); list_for_each(tmp1, &ses->tcon_list) { @@ -573,7 +573,7 @@ is_valid_oplock_break(struct smb_hdr *buf, struct TCP_Server_Info *srv) */ if (netfile->closePend) { spin_unlock(&cifs_file_list_lock); - read_unlock(&cifs_tcp_ses_lock); + spin_unlock(&cifs_tcp_ses_lock); return true; } @@ -595,16 +595,16 @@ is_valid_oplock_break(struct smb_hdr *buf, struct TCP_Server_Info *srv) netfile->oplock_break_cancelled = false; spin_unlock(&cifs_file_list_lock); - read_unlock(&cifs_tcp_ses_lock); + spin_unlock(&cifs_tcp_ses_lock); return true; } spin_unlock(&cifs_file_list_lock); - read_unlock(&cifs_tcp_ses_lock); + spin_unlock(&cifs_tcp_ses_lock); cFYI(1, "No matching file for oplock break"); return true; } } - read_unlock(&cifs_tcp_ses_lock); + spin_unlock(&cifs_tcp_ses_lock); cFYI(1, "Can not process oplock break for non-existent connection"); return true; } |